Safety of Synchronous Laparoscopic Resection of Bilateral Pheochromocytomas/Paragangliomas: A Single-Center Retrospective Study

Safety of Synchronous Laparoscopic Resection of Bilateral Pheochromocytomas/Paragangliomas: A Single-Center Retrospective Study | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Safety of Synchronous Laparoscopic Resection of Bilateral Pheochromocytomas/Paragangliomas: A Single-Center Retrospective Study Wei Liu, Le Shen, Xiaohan Xu, Jiao Zhang, Xuerong Yu This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6979686/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Background Synchronous resection of bilateral pheochromocytomas/paragangliomas (PPGLs) might increase risk of blood loss, hemodynamic instability, and postoperative complications. However, owing to the low incidence of bilateral PPGLs, evidence of safety for these surgeries is not enough, with only case reports available. This study reported a series of bilateral PPGLs case. All the patients received synchronous laparoscopic resection of tumors. Methods Patients underwent synchronous laparoscopic resection of bilateral pheochromocytoma were included. Clinical data including preoperative variables, intraoperative blood loss and transfusion, and postoperative recovery were collected. Results A total of 23 patients were collected. Median intraoperative blood loss was 200 ml (IQR 50, 350), with blood loss/estimated blood volume (EBV) ratio of 3.2%. No allogeneic transfusion required intraoperatively, and the postoperative allogeneic transfusion rate was 4.3%. 82.6% (19/23), 30.4% (7/23), and 17.4% (4/23) of patients required low-dose norepinephrine support at the end of operation, during ICU observation, and at 24 hours respectively. The incidence of postoperative mechanical ventilation duration > 24 h and Foley catheterization duration > 4 days was 17.4% and 13% respectively. ICU and hospital stay duration was 1 day (IQR 1, 1) and 7 days (IQR 4, 7) respectively. Postoperative complication rate was 17.4%. No postoperative mortality and 30-day occured. Conclusion Compared with unilateral tumor resection, we did not find synchronous resection of bilateral PPGLs with more risks of hemorrhage-related complications, hemodynamic fluctuations, or prolonged postoperative recovery. Pheochromocytoma Laparoscopic Resection Bilateral Perioperative Management Safety 1. Introduction Pheochromocytomas and paragangliomas (PPGLs) are neuroendocrine tumors originating from the adrenal medulla (75%-85%) or sympathetic ganglia (15%-25%) [1, 2], with an annual incidence of 0.6–8.3 per 100,000 individuals [3–5]. These tumors are characterized by high mortality [6] and elevated catecholamine related symptoms (e.g., headache, palpitations, hypertension). The standard treatment of PPGLs is resection of the tumor. Perioperative risks include: (1) massive blood loss [7] and high allogeneic transfusion rate due to its proximity to inferior vena cava, renal vasculature, or other abdominal organs [8]; and (2) hypertension and/or tachycardia caused by intraoperative tumor manipulation and life-threatening hypotension after tumor resection due to catecholamine withdrawal and relative hypovolemia [9, 10]. Contemporary laparoscopic techniques and standardized perioperative management have reduced the mortality to 0–3% and the complication rates to 5–22% [11, 12]. PPGLs predominantly occur unilaterally, while bilateral cases constitute only 7–10% [13–15]. Theoretically, simultaneous resection of bilateral tumors might increase the incidence of postoperative complications due to high level of hemorrhagic risk, and hemodynamic fluctuations caused by biphasic catecholamine release ("dual-peak" effect) triggered sequentially during each tumor resection. However, owing to the low incidence of bilateral PPGLs and the clinical preference for conservative staged subsequent procedures, evidences of safety for synchronous adrenalectomy in bilateral PPGLs patients are not enough, with only case reports available [16]. This study aimed to report the safety related data of synchronous laparoscopic resection of bilateral PPGLs which will provide evidence-base guidance to optimize perioperative management strategies and improve patient outcomes. 2. Materials and methods 2.1 Study Subjects This is a single-center retrospective study, which was approved by the ethics Review board of Peking Union Medical College Hospital (Approval number: I-25PJ1398), Informed consent was obtained from all patients by telephone. Patients underwent synchronous laparoscopic resection of bilateral pheochromocytoma in Peking Union Medical College Hospital from January 2013 to June 2024 were included. Cases with incomplete perioperative data were excluded. 2.2 Research Methods 2.2.1 Data collection Clinical data were collected from electronic medical records and anesthesia systems. Preoperative variables included age, sex, body mass index (BMI), preoperative hemoglobin (HGB) and 24-hour urinary catecholamine levels, tumor size and location, preoperative medication, and commodities. Intraoperative blood loss, fluid intake and output, hemoglobin concentration, allogeneic transfusion, and hemodynamic parameters were recorded. Admission-recorded blood pressure was set as baseline. Postoperative hospital/ICU stay duration, complications (defined as deviations from the normal postoperative course recorded in the medical records [17]), and mortality were also collected. 2.2.2 Routine process of perioperative management in patients received resection of pheochromocytoma in our center All patients received ≥ 14 days of preoperative oral non-selective α-blockade (phenoxybenzamine), with dose titration to maintain blood pressure < 140/90 mmHg while ensuring orthostatic systolic BP ≥ 90 mmHg. β-blockers were added as needed to achieve heart rates < 90 bpm. Concurrent volume expansion was encouraged via dietary sodium supplementation. Prior to anesthesia induction, arterial catheters were placed for continuous invasive arterial pressure monitoring, with central venous access established post-induction. Arterial pressure and heart rate were automatically recorded at 10-second intervals throughout surgery. During surgery, anesthesiologists managed hemodynamic fluctuations as follows: when systolic blood pressure exceeded 160 mmHg or increased by more than 30% of baseline, antihypertensive agents such as sodium nitroprusside or phentolamine were administered; conversely, when systolic blood pressure fell below 90 mmHg or decreased by more than 30% of baseline, vasopressors (norepinephrine or epinephrine) were administered alongside aggressive intravenous fluid resuscitation to maintain adequate intravascular volume; additionally, esmolol was utilized for heart rate control when necessary. All patients were transferred to the intensive care unit (ICU) postoperatively. 2.3 Statistical Analysis Given the small sample size (n = 23), all the continuous variables were expressed as median (interquartile range), no matter they were normally distributed or not. Categorical variables were expressed as number and percentage (n (%)). 3. Results This study included a total of 23 patients, with baseline characteristics, preoperative comorbidities, tumor-related data, and preoperative medication preparation detailed in Table 1. Hypertension was the most common preoperative comorbidity (30.4%) in these patients. All patients received preoperative oral α-receptor blockers, while 26.1% additionally used beta-receptor blockers for heart rate control. Preoperative computed tomography（CT）reported a 13.0% incidence of tumors adjacent to blood vessels. Analysis of 24-hour urinary catecholamines revealed elevation of norepinephrine in 19 patients (82.6%), epinephrine in 6 patients (26.1%), and dopamine in 5 patients (21.7%). TABLE 1 Preoperative variables of patients (n = 23) Variable Data Age (years) 40 (34.3,46) Sex 【 N(%) 】 Male 12 (52.2) Female 11 (47.8) Height (cm) 169 (161,175.5) Weight (kg) 61 (54,67) Body mass index (kg/m 2 ) 22.3 (20.4,23.6) Comorbidities (n %) Hypertension 7 (30.4) Diabetes mellitus 5 (21.7) Coronary artery disease 1 (4.3) Catecholamine-induced cardiomyopathy 2 (8.7) Cerebral infarction 1 (4.3) Pancreatic space-occupying lesion 5 (21.7) Hyperuricemia 1 (4.3) Preoperative drug preparation Phenoxybenzamine dose (mg/d) 30 (26.3,30) Phenoxybenzamine time (d) 45.5 (39.3.,56) Beta-blockers (n %) 6 (26.1) Tumor location ( n, %) Unremarkable 20 (87.0) Proximal to vessels/organs a 3 (13.0) T umor size (cm) b 4.4 (3.0,5.5) Urine catecholamine (Reference range) 24‐h urine NE (µg) (16.69-40.65) 659 (653.5,665) 24‐h urine E (µg) (1.74-6.42) 4.9 (3.5,4.9) 24‐h urine DA (µg) (120.93-330.59) 265.2 (194.9,319.1) Abbreviations: CT, computed tomography; DA, dopamine; E, epinephrine; HGB, hemoglobin; NE, norepinephrine. Data were presented as n (%) or median (25th and 75th percentiles). a Proximal to vessels/organs: according to the preoperative CT reports, the tumor compresses and deforms the adjacent vessels (e.g., vena cava, renal veins) or organs. b Tumor size (cm): the size of the tumor is expressed as the maximum diameter of all tumors. Table 2 detailed the perioperative bleeding and transfusion data. The median intraoperative blood loss was 200 ml (IQR 50, 350), with blood loss/EBV ratio of 3.2% and no case exceeding 20%. Intraoperative autologous blood transfusion was performed in 2 patients (248 ml and 462 ml respectively), with no allogeneic transfusion required during surgery. The median postoperative drainage volume was 241 ml (IQR 158.5, 295.5), and the postoperative allogeneic transfusion rate was 4.3%. The median intraoperative minimum hemoglobin and hemoglobin at the end of surgery were 107 g/L (IQR 99.5, 120) and 108 g/L (IQR 102, 122), respectively. TABLE 2 Perioperative bleeding related variables (n=23) Variable Data Intraoperative blood loss Total blood loss (mL) 200 (50,350) Blood loss / EBV a 3.2 (1.4,9.0) Blood loss / EBV ≥20% [n (%)] 0 (0) Hemoglobin Admission HGB (g/L) 132 (115.5,141.5) Preoperative HGB (g/L) 130 (118,135) Intraoperative lowest HGB (g/L) 107 (99.5,120) End‐of‐surgery HGB (g/L) 108 (102,122) Postoperative lowest HGB (g/L) 110 (90.5,118.5) Before discharge HGB (g/L) 113 (98.5,127.8) Transfusion Intraoperative allogeneic blood transfusion [n (%)] 0 (0) Postoperative allogeneic blood transfusion [n (%)] 1 (4.3) Abbreviations: HGB, hemoglobin; EBV, estimated blood volume. Data were presented as n (%) or median (25th and 75th percentiles). a Estimated blood volume (mL), body weight (kg) *0.07/0.65 (Male/Female) *1000. Table 3 showed the perioperative hemodynamic changes. Intraoperatively, nitroprusside, phentolamine, or esmolol was administered to 11 (47.8%), 16 (69.6%), and 7 (30.4%) patients respectively. Norepinephrine was used in 19 patients (82.6%) at a median maximum dose of 0.2 ug/kg/min (IQR 0.1, 0.37), while epinephrine was administered to 2 patients (8.7%). Intraoperative median crystalloid and colloid administration was 3200 ml (IQR 2650, 3600) and 500 ml (IQR 500, 1000) respectively, while urine output was 600 ml (IQR 600, 800). TABLE 3 Perioperative hemodynamic parameters (n =23) Variable Data Admission SBP (mmHg) 131 （118.5，135.5） DBP (mmHg) 85 （78，90） HR (bpm) 94 （80.5，100） Entering the operating room a SBP (mmHg) 140 （122，150.5） DBP (mmHg) 90 （81，99） HR (bpm) 85 （74，100） During surgery SBPmax >200 mm Hg [n (%)] 5 (21.7) SBPmax (mmHg) 172 （160.5，195） SBPmin (mmHg) 86 （80，92） DBPmax (mmHg) 100 （91，114） DBPmin (mmHg) 50 （42，52.5） HRmax > 110 bpm [n, (%)] 10 (43.5) A t the end of surgery SBP (mmHg) 112 （110，16.5） DBP (mmHg) 60 （57.5，72） HR (bpm) 82 （75，90.5） Continuous infusion of vasopressor [n, (%)] 19 (82.6) Dose of Norepinephrine (ug/kg/min) 0.2 （0.04，0.3） Postoperative use of vasopressors [n, (%)] 7 (30.4) Postoperative use of vasopressors >24 h [n, (%)] 4 (17.4) Abbreviations: SBP, systolic blood pressure; DBP, diastolic blood pressure; HR, heart rate; bpm, beats per minute; mmHg, millimeters of mercury. Data were presented as n (%) or median (25th and 75th percentiles). a Entering the operating room, the first blood pressure and heart rate taken after entering the operating room The median operating time was 210 minutes (IQR 150, 240). The incidence of postoperative mechanical ventilation duration >24 h was 17.4%, while Foley catheterization duration >4 days was 13%. ICU and hospital stay duration was 1 day (IQR 1, 1) and 7 days (IQR 4, 7) respectively. Postoperative complication rate was 17.4%; and the detail was shown in Table 4. Both postoperative mortality and 30-day readmission rates were 0%. TABLE 4 Postoperative parameters and outcomes (n = 23) Variable Data Operative duration a (min) 210 (150,240) ICU stay duration (d) 1 (1,1) Hospital stay duration (d) 7 (4,7) Postoperative mechanical ventilation duration >24 h [n (%)] 4 (17.4%) Postoperative Foley catheter drainage duration >4d [n (%)] 3 (13.0%) Postoperative complications [n (%)] Adrenal cortical insufficiency 1 (4.3) DVT 1 (4.3) Pulmonary infection+ Blood transfusion 1 (4.3) Elevated myocardial enzymes 1 (4.3) Death 0 (0) Hospitalization within 30 days after the operation 0 (0) Abbreviations: DVT, Deep Vein Thrombosis. Data were presented as n (%) or median (25th and 75th percentiles). a Operative duration: the time from skin incision to skin closure. 4. Discussion 23 cases were presented in this study which gave some evidence of safety in synchronous bilateral laparoscopic resection for pheochromocytomas/paragangliomas. There were several theoretical concerns for single-stage bilateral resection in these patients. First, the anatomical nature of these tumors increases the risks of massive hemorrhage during resection, potentially exacerbating hemodynamic instability and allogeneic transfusion-related complications [18, 19]. These risks might be amplified by bilateral resection. Second, catecholamine release during tumor manipulation may induce profound hemodynamic instability and cardiovascular risks, where bilateral resection prolongs exposure of these risks. Last, the surgical trauma of bilateral resection could increase postoperative morbidity, potentially prolonging mechanical ventilation, ICU/hospital stays, and complication rates. Owing to the rich vascularization of PPGLs, there were more intraoperative blood loss in these patients compared with other adrenal neoplasms [8, 20, 21]. For example, Natkaniec et al. [20] reported that among 437 patients undergoing adrenal surgery, those with pheochromocytoma (n= 124) had significantly higher mean blood loss (117 mL) compared to other adrenal surgery patients (n = 313, 54 mL). In the present study, patients undergoing synchronous bilateral pheochromocytoma resection had a median blood loss of 200 mL (IQR 50-350 mL). This was similar with the 198 mL reported by Liu et al. [18] from our center. According to UK Guidelines for Autologous Transfusion [22] transfusion risk increases when intraoperative blood loss exceeds 20% of estimated blood volume (EBV). Here, the median of intraoperative blood loss accounted for approximately 3.2% of EBV, with no cases exceeding the 20% of EBV. Two patients received autologous red blood cell transfusion via a cell saver system. No allogeneic transfusions were administered intraoperatively, and the postoperative transfusion rate was 4.3% (1/23). Previous data from our center on unilateral resections demonstrate higher bleeding risks: Liu et al. [23] reported intraoperative blood loss exceeding 20% EBV in 43.3% (Glg group), 12.3% (Gmd group), and 6.6% (Gsm group) of patients. Ma et al. [24] documented an 8.2% postoperative allogeneic transfusion rate. Collectively, these findings suggest that simultaneous resection of bilateral PPGLs did not increase perioperative bleeding or transfusion risks compared to unilateral procedures. Hemoglobin was monitored in all 23 patients, indicating that intraoperative HGB fluctuations remained well below the transfusion threshold. Furthermore, postoperative HGB showed no progressive decline and recovered rapidly. Intraoperative circulatory stability was maintained in this cohort through pharmacologic and fluid management. Vasoactive agent requirements showed a stepwise decline postoperatively. 82.6% (19/23) and 17.4% (4/23) of patients required low-dose norepinephrine support at the end of surgery and at 24 hours respectively. The latter one was no more than the incidence (27.7%) reported by Liu et al in the unilateral small-tumor subgroup.[23]. The operating duration in the present study was 210 (150–240) min, which was longer than which (117.3 ± 60.0 min) reported by Lan et al[25] from our center. However, it was similar to which reported by Liu et al[23] for unilateral resection of larger tumors (175（142.5，236.25） min) and which reported by Ma et al [24] for unilateral tumor resection in patients with preoperative comorbidities [190 (135–262.5) min]. This suggests that simultaneous bilateral tumor resection may prolong operating duration to some extent, but the degree of prolongation was no more than that observed in unilateral resections performed under other challenging circumstances, such as for large tumors or in patients with preoperative comorbidities. In the present study, postoperative complication rate among the 23 patients was 17.4%, while other literature reported a range of 11.4% to 29.8% for pheochromocytoma surgery [24, 26-28]. And recent report of our center was 14.8% for unilateral tumor resection [24]. Importantly, there were no mortalities or 30-day readmissions in our cases. Cardiovascular events represent the most common postoperative complications following pheochromocytoma surgery [29-32]. Data from our center have consistently reported a low incidence of postoperative complication. For instance, Ma et al. reported a single case of arrhythmia [24] among 438 patients received unilateral resection of PPGLs. Similarly, Lan et al. (n = 350, unilateral resections) reported one case of myocardial infarction [25]. In our study, only one case of transient postoperative myocardial enzyme elevation and electrocardiographic (ECG) abnormalities was observed. Postoperative recovery of our 23 patients demonstrated four characteristics. (1) ICU stay duration was 1 day (IQR 1,1), lower than the 2 days reported in earlier studies [18, 23] and consistent with recent data from our institution [24]. (2) Although Major et al. advocated no drainage after uncomplicated laparoscopic surgery [33], all patients in our study received drainage due to pheochromocytoma’s high bleeding risk, with a median removal time of 3 days (IQR 3,4) and 13% of whom retaining drains >4 days, similar with our center's previous data (9%-20%) [23]. (3) Prolonged mechanical ventilation (>24 hours) occurred in 17.4% of our patients, which was similar with our center’s previous report of unilateral resection cohort (20% in Liu et al., [23]). Furthermore, all patients maintained post-extubating hemodynamic stability without vasopressor support. (4) Postoperative hospitalization (median 7 days, IQR 4,7) and total hospitalization (median 15 days, IQR 13-18) aligned with our institution’s data of unilateral resection [23, 24]. Collectively, these findings indicate that synchronous bilateral resection of PPGLs did not significantly prolong recovery. As the incidence of bilateral PPGLs is low, reports about the safety of synchronous bilateral resection were rare. In our study, 23 patients’ data were presented detailedly, providing some evidence to help surgical decision-making. However, our findings should be interpreted with caution due to several limitations. First, as a retrospective case series with a modest sample size, statistical analyses and causal inferences have not been implemented, resulting in low evidence strength; Second, all the cases were from a single center, our conclusions may not be applicable to different contexts. Finally, postoperative complications might be underestimated due to incomplete retrospective documentation. In conclusion, this study reported 23 patients with bilateral pheochromocytomas / paragangliomas who underwent laparoscopic synchronous bilateral tumor resection. Compared with unilateral tumor resection, we did not find the bilateral procedures with more risks of hemorrhage-related complications, hemodynamic fluctuations, or prolonged postoperative recovery. Abbreviations BMI Body Mass Index CT Computed Tomography DA Dopamine DBP Diastolic Blood Pressure DVT Deep Vein Thrombosis E Epinephrine EBV Estimated Blood Volume HR Heart Rate HGB Hemoglobin IQR Interquartile Range ICU Intensive Care Unit NE Norepinephrine PPGLs Pheochromocytomas/Paragangliomas SBP Systolic Blood Pressure Declarations Acknowledgments We thank the anonymous reviewers for their valuable comments. Responsibility for any remaining errors rests solely with the authors. Author contributions LW Data collection, Statistical analysis, Manuscript. Draft SL Study design. XX Statistical analyis. JZ Data collection. XY Study design, Statistical analysis, Manuscript revision. All authors have contributed to the article and approved the submitted version. Funding No external funding was provided for the planning and conduct of the research or preparation of the manuscript. Data availability statement The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request. Ethics approval and consent to participate The study was reviewed and approved by Peking Union Medical College Hospital (Approval number: I-25PJ1398), Informed consent was obtained from all patients by telephone. Consent for publication All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher. Competing interests The authors have no conflicts of interest to declare. References Emilsson H. High-performance liquid chromatographic determination of cadralazine in human plasma and urine. 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Surgery. 2016;159(3):763 − 70.http://dx.doi.org/10.1016/j.surg.2015.09.016 Shen WT, Grogan R, Vriens M, Clark OH, Duh QY. One hundred two patients with pheochromocytoma treated at a single institution since the introduction of laparoscopic adrenalectomy. Arch Surg. 2010;145(9):893-7.http://dx.doi.org/10.1001/archsurg.2010.159 Major P, Matlok M, Pedziwiatr M, Budzynski A. Do we really need routine drainage after laparoscopic adrenalectomy and splenectomy? Wideochir Inne Tech Maloinwazyjne. 2012;7(1):33 − 9.http://dx.doi.org/10.5114/wiitm.2011.25610 Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-6979686","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":496411171,"identity":"9dedb853-b377-42dc-a7ec-6da81c9acff1","order_by":0,"name":"Wei Liu","email":"","orcid":"","institution":"Peking Union Medical College Hospital","correspondingAuthor":false,"prefix":"","firstName":"Wei","middleName":"","lastName":"Liu","suffix":""},{"id":496411172,"identity":"7fc1f646-9b1e-4d94-b690-5472f7412ebf","order_by":1,"name":"Le Shen","email":"","orcid":"","institution":"Peking Union Medical College Hospital","correspondingAuthor":false,"prefix":"","firstName":"Le","middleName":"","lastName":"Shen","suffix":""},{"id":496411173,"identity":"03695342-4847-4fb2-9f47-2752631f6c20","order_by":2,"name":"Xiaohan Xu","email":"","orcid":"","institution":"Peking Union Medical College Hospital","correspondingAuthor":false,"prefix":"","firstName":"Xiaohan","middleName":"","lastName":"Xu","suffix":""},{"id":496411174,"identity":"cc774f78-21f6-44b0-8c34-5b4aa1616bea","order_by":3,"name":"Jiao Zhang","email":"","orcid":"","institution":"Peking Union Medical College Hospital","correspondingAuthor":false,"prefix":"","firstName":"Jiao","middleName":"","lastName":"Zhang","suffix":""},{"id":496411175,"identity":"55e49080-bf79-468e-8ff8-c3d273a9d4b6","order_by":4,"name":"Xuerong Yu","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAxUlEQVRIiWNgGAWjYFAD9gYQeYAULTwHSNYikUCkFoMbOWYSH/fY5MlHvj0mdaPmDgP/7AZCWtLSJGc8Sys2vJ2XJp1z7BmDxB0CNhncSD4mzXPgcOLG2Tlm0rkNhxkMIC7EpyWxTfoPSMvMM0RrAdrCANQyX4KHSC2SZ54lW/YcSEvcwJOXbJ1z7DCPxA0CWviO5xje+HHAJnF++9mDt3NqDsvxzyCgReEAzIUHeMA0D371QCDfAGcQVjwKRsEoGAUjFAAASwhJdB9jZqkAAAAASUVORK5CYII=","orcid":"","institution":"Peking Union Medical College Hospital","correspondingAuthor":true,"prefix":"","firstName":"Xuerong","middleName":"","lastName":"Yu","suffix":""}],"badges":[],"createdAt":"2025-06-26 05:23:15","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6979686/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6979686/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":105368184,"identity":"fa8b8098-85c0-496d-bbd4-ec42656ebad9","added_by":"auto","created_at":"2026-03-25 08:57:52","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":899776,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6979686/v1/77ed6087-5002-4fe6-8aaa-8cf3bb4e5ff5.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Safety of Synchronous Laparoscopic Resection of Bilateral Pheochromocytomas/Paragangliomas: A Single-Center Retrospective Study","fulltext":[{"header":"1. Introduction","content":"\u003cp\u003ePheochromocytomas and paragangliomas (PPGLs) are neuroendocrine tumors originating from the adrenal medulla (75%-85%) or sympathetic ganglia (15%-25%) [1, 2], with an annual incidence of 0.6\u0026ndash;8.3 per 100,000 individuals [3\u0026ndash;5]. These tumors are characterized by high mortality [6] and elevated catecholamine related symptoms (e.g., headache, palpitations, hypertension). The standard treatment of PPGLs is resection of the tumor. Perioperative risks include: (1) massive blood loss [7] and high allogeneic transfusion rate due to its proximity to inferior vena cava, renal vasculature, or other abdominal organs [8]; and (2) hypertension and/or tachycardia caused by intraoperative tumor manipulation and life-threatening hypotension after tumor resection due to catecholamine withdrawal and relative hypovolemia [9, 10]. Contemporary laparoscopic techniques and standardized perioperative management have reduced the mortality to 0\u0026ndash;3% and the complication rates to 5\u0026ndash;22% [11, 12].\u003c/p\u003e\u003cp\u003ePPGLs predominantly occur unilaterally, while bilateral cases constitute only 7\u0026ndash;10% [13\u0026ndash;15]. Theoretically, simultaneous resection of bilateral tumors might increase the incidence of postoperative complications due to high level of hemorrhagic risk, and hemodynamic fluctuations caused by biphasic catecholamine release (\"dual-peak\" effect) triggered sequentially during each tumor resection. However, owing to the low incidence of bilateral PPGLs and the clinical preference for conservative staged subsequent procedures, evidences of safety for synchronous adrenalectomy in bilateral PPGLs patients are not enough, with only case reports available [16].\u003c/p\u003e\u003cp\u003eThis study aimed to report the safety related data of synchronous laparoscopic resection of bilateral PPGLs which will provide evidence-base guidance to optimize perioperative management strategies and improve patient outcomes.\u003c/p\u003e"},{"header":"2. Materials and methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\u003ch2\u003e2.1 Study Subjects\u003c/h2\u003e\u003cp\u003e This is a single-center retrospective study, which was approved by the ethics Review board of Peking Union Medical College Hospital (Approval number: I-25PJ1398), Informed consent was obtained from all patients by telephone.\u003c/p\u003e\u003cp\u003ePatients underwent synchronous laparoscopic resection of bilateral pheochromocytoma in Peking Union Medical College Hospital from January 2013 to June 2024 were included. Cases with incomplete perioperative data were excluded.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec4\" class=\"Section2\"\u003e\u003ch2\u003e2.2 Research Methods\u003c/h2\u003e\u003cdiv id=\"Sec5\" class=\"Section3\"\u003e\u003ch2\u003e2.2.1 Data collection\u003c/h2\u003e\u003cp\u003eClinical data were collected from electronic medical records and anesthesia systems. Preoperative variables included age, sex, body mass index (BMI), preoperative hemoglobin (HGB) and 24-hour urinary catecholamine levels, tumor size and location, preoperative medication, and commodities. Intraoperative blood loss, fluid intake and output, hemoglobin concentration, allogeneic transfusion, and hemodynamic parameters were recorded. Admission-recorded blood pressure was set as baseline. Postoperative hospital/ICU stay duration, complications (defined as deviations from the normal postoperative course recorded in the medical records [17]), and mortality were also collected.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec6\" class=\"Section3\"\u003e\u003ch2\u003e2.2.2 Routine process of perioperative management in patients received resection of pheochromocytoma in our center\u003c/h2\u003e\u003cp\u003eAll patients received\u0026thinsp;\u0026ge;\u0026thinsp;14 days of preoperative oral non-selective α-blockade (phenoxybenzamine), with dose titration to maintain blood pressure\u0026thinsp;\u0026lt;\u0026thinsp;140/90 mmHg while ensuring orthostatic systolic BP\u0026thinsp;\u0026ge;\u0026thinsp;90 mmHg. β-blockers were added as needed to achieve heart rates\u0026thinsp;\u0026lt;\u0026thinsp;90 bpm. Concurrent volume expansion was encouraged via dietary sodium supplementation. Prior to anesthesia induction, arterial catheters were placed for continuous invasive arterial pressure monitoring, with central venous access established post-induction. Arterial pressure and heart rate were automatically recorded at 10-second intervals throughout surgery.\u003c/p\u003e\u003cp\u003eDuring surgery, anesthesiologists managed hemodynamic fluctuations as follows: when systolic blood pressure exceeded 160 mmHg or increased by more than 30% of baseline, antihypertensive agents such as sodium nitroprusside or phentolamine were administered; conversely, when systolic blood pressure fell below 90 mmHg or decreased by more than 30% of baseline, vasopressors (norepinephrine or epinephrine) were administered alongside aggressive intravenous fluid resuscitation to maintain adequate intravascular volume; additionally, esmolol was utilized for heart rate control when necessary.\u003c/p\u003e\u003cp\u003eAll patients were transferred to the intensive care unit (ICU) postoperatively.\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv id=\"Sec7\" class=\"Section2\"\u003e\u003ch2\u003e2.3 Statistical Analysis\u003c/h2\u003e\u003cp\u003eGiven the small sample size (n\u0026thinsp;=\u0026thinsp;23), all the continuous variables were expressed as median (interquartile range), no matter they were normally distributed or not. Categorical variables were expressed as number and percentage (n (%)).\u003c/p\u003e\u003c/div\u003e"},{"header":"3. Results","content":"\u003cp\u003eThis study included a total of 23 patients, with baseline characteristics, preoperative comorbidities, tumor-related data, and preoperative medication preparation detailed in Table 1. Hypertension was the most common preoperative comorbidity (30.4%) in these patients. All patients received preoperative oral \u0026alpha;-receptor blockers, while 26.1% additionally used beta-receptor blockers for heart rate control. Preoperative computed tomography（CT）reported a 13.0% incidence of tumors adjacent to blood vessels. Analysis of 24-hour urinary catecholamines revealed elevation of norepinephrine in 19 patients (82.6%), epinephrine in 6 patients (26.1%), and dopamine in 5 patients (21.7%).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTABLE\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003e1\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003ePreoperative variables of patients (n = 23)\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"99%\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 62.6263%;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp;Variable\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 37.3737%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eData\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 62.6263%;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp;Age (years)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 37.3737%;\"\u003e\n \u003cp\u003e40 (34.3,46)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 62.6263%;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003cstrong\u003eSex\u003c/strong\u003e\u003cstrong\u003e【\u003c/strong\u003e\u003cstrong\u003eN(%)\u003c/strong\u003e\u003cstrong\u003e】\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 37.3737%;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 62.6263%;\"\u003e\n \u003cp\u003eMale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 37.3737%;\"\u003e\n \u003cp\u003e12 (52.2)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 62.6263%;\"\u003e\n \u003cp\u003eFemale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 37.3737%;\"\u003e\n \u003cp\u003e11 (47.8)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 62.6263%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eHeight (cm)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 37.3737%;\"\u003e\n \u003cp\u003e169 (161,175.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 62.6263%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eWeight (kg)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 37.3737%;\"\u003e\n \u003cp\u003e61 (54,67)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 62.6263%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eBody mass index (kg/m\u003csup\u003e2\u003c/sup\u003e)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 37.3737%;\"\u003e\n \u003cp\u003e22.3 (20.4,23.6)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 62.6263%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eComorbidities\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;(n %)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 37.3737%;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 62.6263%;\"\u003e\n \u003cp\u003e\u0026nbsp; Hypertension\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 37.3737%;\"\u003e\n \u003cp\u003e7 (30.4)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 62.6263%;\"\u003e\n \u003cp\u003e\u0026nbsp;Diabetes mellitus\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 37.3737%;\"\u003e\n \u003cp\u003e5 (21.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 62.6263%;\"\u003e\n \u003cp\u003eCoronary artery disease\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 37.3737%;\"\u003e\n \u003cp\u003e1 (4.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 62.6263%;\"\u003e\n \u003cp\u003eCatecholamine-induced\u0026nbsp;\u003c/p\u003e\n \u003cp\u003ecardiomyopathy\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 37.3737%;\"\u003e\n \u003cp\u003e2 (8.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 62.6263%;\"\u003e\n \u003cp\u003eCerebral infarction\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 37.3737%;\"\u003e\n \u003cp\u003e1 (4.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 62.6263%;\"\u003e\n \u003cp\u003ePancreatic space-occupying lesion\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 37.3737%;\"\u003e\n \u003cp\u003e5 (21.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 62.6263%;\"\u003e\n \u003cp\u003eHyperuricemia\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 37.3737%;\"\u003e\n \u003cp\u003e1 (4.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 62.6263%;\"\u003e\n \u003cp\u003e\u003cstrong\u003ePreoperative drug preparation\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 37.3737%;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 62.6263%;\"\u003e\n \u003cp\u003ePhenoxybenzamine dose (mg/d)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 37.3737%;\"\u003e\n \u003cp\u003e30 (26.3,30)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 62.6263%;\"\u003e\n \u003cp\u003ePhenoxybenzamine time (d)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 37.3737%;\"\u003e\n \u003cp\u003e45.5 (39.3.,56)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 62.6263%;\"\u003e\n \u003cp\u003eBeta-blockers (n %)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 37.3737%;\"\u003e\n \u003cp\u003e6 (26.1)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 62.6263%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eTumor location (\u003c/strong\u003en, %)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 37.3737%;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 62.6263%;\"\u003e\n \u003cp\u003eUnremarkable\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 37.3737%;\"\u003e\n \u003cp\u003e20 (87.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 62.6263%;\"\u003e\n \u003cp\u003eProximal to vessels/organs \u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 37.3737%;\"\u003e\n \u003cp\u003e3 (13.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 62.6263%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eT\u003c/strong\u003e\u003cstrong\u003eumor size (cm)\u0026nbsp;\u003c/strong\u003e\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 37.3737%;\"\u003e\n \u003cp\u003e4.4 (3.0,5.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 62.6263%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eUrine catecholamine (Reference range)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 37.3737%;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 62.6263%;\"\u003e\n \u003cp\u003e24‐h urine NE (\u0026micro;g) (16.69-40.65)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 37.3737%;\"\u003e\n \u003cp\u003e659 (653.5,665)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 62.6263%;\"\u003e\n \u003cp\u003e24‐h urine E (\u0026micro;g) (1.74-6.42)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 37.3737%;\"\u003e\n \u003cp\u003e4.9\u0026nbsp;(3.5,4.9)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 62.6263%;\"\u003e\n \u003cp\u003e24‐h urine DA (\u0026micro;g) (120.93-330.59)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 37.3737%;\"\u003e\n \u003cp\u003e265.2\u0026nbsp;(194.9,319.1)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eAbbreviations: CT, computed tomography; DA, dopamine; E, epinephrine; HGB, hemoglobin; NE, norepinephrine.\u003c/p\u003e\n\u003cp\u003eData were presented as n (%) or median (25th and 75th percentiles).\u003c/p\u003e\n\u003cp\u003ea Proximal to vessels/organs: according to the preoperative CT reports, the tumor compresses and deforms the adjacent vessels (e.g., vena cava, renal veins) or organs.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eb Tumor size (cm): the size of the tumor is expressed as the maximum diameter of all tumors.\u003c/p\u003e\n\u003cp\u003eTable 2 detailed the perioperative bleeding and transfusion data. The median intraoperative blood loss was 200 ml (IQR 50, 350), with blood loss/EBV ratio of 3.2% and no case exceeding 20%. Intraoperative autologous blood transfusion was performed in 2 patients (248 ml and 462 ml respectively), with no allogeneic transfusion required during surgery. The median postoperative drainage volume was 241 ml (IQR 158.5, 295.5), and the postoperative allogeneic transfusion rate was 4.3%. The median intraoperative minimum hemoglobin and hemoglobin at the end of surgery were 107 g/L (IQR 99.5, 120) and 108 g/L (IQR 102, 122), respectively.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTABLE 2 Perioperative bleeding related variables (n=23)\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"99%\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 67.6768%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eVariable\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 32.3232%;\"\u003e\n \u003cp\u003eData\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 67.6768%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eIntraoperative blood loss\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 32.3232%;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 67.6768%;\"\u003e\n \u003cp\u003eTotal blood loss (mL)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 32.3232%;\"\u003e\n \u003cp\u003e200 (50,350)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 67.6768%;\"\u003e\n \u003cp\u003eBlood loss / EBV \u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 32.3232%;\"\u003e\n \u003cp\u003e3.2 (1.4,9.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 67.6768%;\"\u003e\n \u003cp\u003eBlood loss / EBV \u0026ge;20% [n (%)]\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 32.3232%;\"\u003e\n \u003cp\u003e0 (0)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 67.6768%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eHemoglobin\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 32.3232%;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 67.6768%;\"\u003e\n \u003cp\u003eAdmission HGB (g/L)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 32.3232%;\"\u003e\n \u003cp\u003e132 (115.5,141.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 67.6768%;\"\u003e\n \u003cp\u003ePreoperative HGB (g/L)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 32.3232%;\"\u003e\n \u003cp\u003e130 (118,135)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 67.6768%;\"\u003e\n \u003cp\u003eIntraoperative lowest HGB (g/L)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 32.3232%;\"\u003e\n \u003cp\u003e107 (99.5,120)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 67.6768%;\"\u003e\n \u003cp\u003eEnd‐of‐surgery HGB (g/L)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 32.3232%;\"\u003e\n \u003cp\u003e108 (102,122)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 67.6768%;\"\u003e\n \u003cp\u003ePostoperative\u0026nbsp;lowest HGB (g/L)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 32.3232%;\"\u003e\n \u003cp\u003e110 (90.5,118.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 67.6768%;\"\u003e\n \u003cp\u003eBefore discharge HGB (g/L)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 32.3232%;\"\u003e\n \u003cp\u003e113 (98.5,127.8)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 67.6768%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eTransfusion\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 32.3232%;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 67.6768%;\"\u003e\n \u003cp\u003eIntraoperative allogeneic blood transfusion [n (%)]\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 32.3232%;\"\u003e\n \u003cp\u003e0 (0)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 67.6768%;\"\u003e\n \u003cp\u003ePostoperative allogeneic blood transfusion [n (%)]\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 32.3232%;\"\u003e\n \u003cp\u003e1 (4.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eAbbreviations: HGB, hemoglobin; EBV, estimated blood volume.\u003c/p\u003e\n\u003cp\u003eData were presented as n (%) or median (25th and 75th percentiles).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003ea Estimated blood volume (mL), body weight (kg) *0.07/0.65 (Male/Female) *1000.\u003c/p\u003e\n\u003cp\u003eTable 3 showed the perioperative hemodynamic changes. Intraoperatively, nitroprusside, phentolamine, or esmolol was administered to 11 (47.8%), 16 (69.6%), and 7 (30.4%) patients respectively. Norepinephrine was used in 19 patients (82.6%) at a median maximum dose of 0.2 ug/kg/min (IQR 0.1, 0.37), while epinephrine was administered to 2 patients (8.7%). Intraoperative median crystalloid and colloid administration was 3200 ml (IQR 2650, 3600) and 500 ml (IQR 500, 1000) respectively, while urine output was 600 ml (IQR 600, 800).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTABLE 3 Perioperative hemodynamic parameters (n\u003c/strong\u003e\u003cstrong\u003e=23)\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"100%\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 66.6667%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eVariable\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eData\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 66.6667%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eAdmission\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 66.6667%;\"\u003e\n \u003cp\u003eSBP (mmHg)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003e131\u0026nbsp;（118.5，135.5）\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 66.6667%;\"\u003e\n \u003cp\u003eDBP (mmHg)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003e85\u0026nbsp;（78，90）\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 66.6667%;\"\u003e\n \u003cp\u003eHR (bpm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003e94\u0026nbsp;（80.5，100）\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 66.6667%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eEntering the operating room \u003csup\u003ea\u003c/sup\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 66.6667%;\"\u003e\n \u003cp\u003eSBP (mmHg)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003e140\u0026nbsp;（122，150.5）\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 66.6667%;\"\u003e\n \u003cp\u003eDBP (mmHg)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003e90\u0026nbsp;（81，99）\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 66.6667%;\"\u003e\n \u003cp\u003eHR (bpm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003e85\u0026nbsp;（74，100）\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 66.6667%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eDuring surgery\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 66.6667%;\"\u003e\n \u003cp\u003eSBPmax \u0026gt;200 mm Hg [n (%)]\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003e5 (21.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 66.6667%;\"\u003e\n \u003cp\u003eSBPmax (mmHg)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003e172\u0026nbsp;（160.5，195）\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 66.6667%;\"\u003e\n \u003cp\u003eSBPmin (mmHg)\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003e86\u0026nbsp;（80，92）\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 66.6667%;\"\u003e\n \u003cp\u003eDBPmax (mmHg)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003e100\u0026nbsp;（91，114）\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 66.6667%;\"\u003e\n \u003cp\u003eDBPmin (mmHg)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003e50\u0026nbsp;（42，52.5）\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 66.6667%;\"\u003e\n \u003cp\u003eHRmax \u0026gt; 110 bpm [n, (%)]\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003e10 (43.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 66.6667%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eA\u003c/strong\u003e\u003cstrong\u003et the end of surgery\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 66.6667%;\"\u003e\n \u003cp\u003eSBP (mmHg)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003e112\u0026nbsp;（110，16.5）\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 66.6667%;\"\u003e\n \u003cp\u003eDBP (mmHg)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003e60\u0026nbsp;（57.5，72）\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 66.6667%;\"\u003e\n \u003cp\u003eHR (bpm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003e82\u0026nbsp;（75，90.5）\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 66.6667%;\"\u003e\n \u003cp\u003eContinuous infusion of vasopressor [n, (%)]\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003e19 (82.6)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 66.6667%;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003eDose of Norepinephrine (ug/kg/min)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003e0.2\u0026nbsp;（0.04，0.3）\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 66.6667%;\"\u003e\n \u003cp\u003e\u003cstrong\u003ePostoperative use of vasopressors\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;[n, (%)]\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003e7 (30.4)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 66.6667%;\"\u003e\n \u003cp\u003e\u003cstrong\u003ePostoperative use of vasopressors \u0026gt;24 h\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;[n, (%)]\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 33.3333%;\"\u003e\n \u003cp\u003e4 (17.4)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eAbbreviations:\u0026nbsp;SBP, systolic blood pressure; DBP, diastolic blood pressure; HR, heart rate; bpm, beats per minute; mmHg, millimeters of mercury.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eData were presented as n (%) or median (25th and 75th percentiles).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003ea Entering the operating room, the first blood pressure and heart rate taken after entering the operating room\u003c/p\u003e\n\u003cp\u003eThe median operating time was 210 minutes (IQR 150, 240). The incidence of postoperative mechanical ventilation duration \u0026gt;24 h was 17.4%, while Foley catheterization duration \u0026gt;4 days was 13%. ICU and hospital stay duration was 1 day (IQR 1, 1) and 7 days (IQR 4, 7) respectively. Postoperative complication rate was 17.4%; and the detail was shown in Table 4. Both postoperative mortality and 30-day readmission rates were 0%.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTABLE 4 Postoperative\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;parameters and outcomes\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;(n = 23)\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" align=\"left\" width=\"99%\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 68.6869%;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp; \u0026nbsp;Variable\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 31.3131%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eData\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 68.6869%;\"\u003e\n \u003cp\u003eOperative duration \u003csup\u003ea\u003c/sup\u003e(min)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 31.3131%;\"\u003e\n \u003cp\u003e210 (150,240)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 68.6869%;\"\u003e\n \u003cp\u003eICU stay duration (d)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 31.3131%;\"\u003e\n \u003cp\u003e1 (1,1)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 68.6869%;\"\u003e\n \u003cp\u003eHospital stay duration (d)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 31.3131%;\"\u003e\n \u003cp\u003e7 (4,7)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 68.6869%;\"\u003e\n \u003cp\u003ePostoperative mechanical ventilation duration \u0026gt;24 h [n (%)]\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 31.3131%;\"\u003e\n \u003cp\u003e4 (17.4%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 68.6869%;\"\u003e\n \u003cp\u003ePostoperative Foley catheter drainage duration \u0026gt;4d [n (%)]\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 31.3131%;\"\u003e\n \u003cp\u003e3 (13.0%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 68.6869%;\"\u003e\n \u003cp\u003ePostoperative complications [n (%)]\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 31.3131%;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 68.6869%;\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; Adrenal cortical insufficiency\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 31.3131%;\"\u003e\n \u003cp\u003e1 (4.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 68.6869%;\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; DVT\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 31.3131%;\"\u003e\n \u003cp\u003e1 (4.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 68.6869%;\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; Pulmonary infection+ Blood transfusion\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 31.3131%;\"\u003e\n \u003cp\u003e1 (4.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 68.6869%;\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; Elevated myocardial enzymes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 31.3131%;\"\u003e\n \u003cp\u003e1 (4.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 68.6869%;\"\u003e\n \u003cp\u003e\u0026nbsp;Death\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 31.3131%;\"\u003e\n \u003cp\u003e0 (0)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 68.6869%;\"\u003e\n \u003cp\u003e\u0026nbsp;Hospitalization within 30 days after the operation\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 31.3131%;\"\u003e\n \u003cp\u003e0 (0)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eAbbreviations: \u0026nbsp;DVT, Deep Vein Thrombosis.\u003c/p\u003e\n\u003cp\u003eData were presented as n (%) or median (25th and 75th percentiles).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003ea Operative duration: the time from skin incision to skin closure.\u003c/p\u003e"},{"header":"4. Discussion","content":"\u003cp\u003e23 cases were presented in this study which gave some evidence of safety in synchronous bilateral laparoscopic resection for pheochromocytomas/paragangliomas. There were several theoretical concerns for single-stage bilateral resection in these patients. First, the anatomical nature of these tumors increases the risks of massive hemorrhage during resection, potentially exacerbating hemodynamic instability and allogeneic transfusion-related complications [18, 19]. These risks might be amplified by bilateral resection. Second, catecholamine release during tumor manipulation may induce profound hemodynamic instability and cardiovascular risks, where bilateral resection prolongs exposure of these risks. Last, the surgical trauma of bilateral resection could increase postoperative morbidity, potentially prolonging mechanical ventilation, ICU/hospital stays, and complication rates.\u003c/p\u003e\n\u003cp\u003eOwing to the rich vascularization of PPGLs, there were more intraoperative blood loss in these patients compared with other adrenal neoplasms [8, 20, 21]. For example, Natkaniec et al. [20] reported that among 437 patients undergoing adrenal surgery, those with pheochromocytoma (n= 124) had significantly higher mean blood loss (117 mL) compared to other adrenal surgery patients (n = 313, 54 mL). In the present study, patients undergoing synchronous bilateral pheochromocytoma resection had a median blood loss of 200 mL (IQR 50-350 mL). This was similar with the 198 mL reported by Liu et al. [18] from our center. According to UK Guidelines for Autologous Transfusion [22] transfusion risk increases when intraoperative blood loss exceeds 20% of estimated blood volume (EBV). Here, the median of intraoperative blood loss accounted for approximately 3.2% of EBV, with no cases exceeding the 20% of EBV. Two patients received autologous red blood cell transfusion via a cell saver system. No allogeneic transfusions were administered intraoperatively, and the postoperative transfusion rate was 4.3% (1/23). Previous data from our center on unilateral resections demonstrate higher bleeding risks: Liu et al. [23] reported intraoperative blood loss exceeding 20% EBV in 43.3% (Glg group), 12.3% (Gmd group), and 6.6% (Gsm group) of patients. Ma et al. [24] documented an 8.2% postoperative allogeneic transfusion rate. Collectively, these findings suggest that simultaneous resection of bilateral PPGLs did not increase perioperative bleeding or transfusion risks compared to unilateral procedures. Hemoglobin was monitored in all 23 patients, indicating that intraoperative HGB fluctuations remained well below the transfusion threshold. Furthermore,\u0026nbsp;postoperative HGB showed no progressive decline and recovered rapidly.\u003c/p\u003e\n\u003cp\u003eIntraoperative circulatory stability was maintained in this cohort through pharmacologic and fluid management. Vasoactive agent requirements showed a stepwise decline postoperatively. 82.6% (19/23) and 17.4% (4/23) of patients required low-dose norepinephrine support at the end of surgery and at 24 hours respectively. The latter one was no more\u0026nbsp;than the incidence (27.7%) reported by Liu et al in the unilateral small-tumor subgroup.[23].\u003c/p\u003e\n\u003cp\u003eThe operating duration in the present study was 210 (150–240) min, which was longer than which (117.3 ± 60.0 min) reported by Lan et al[25] from our center. However, it was similar to which reported by Liu et al[23] for unilateral resection of larger tumors (175（142.5，236.25）\u0026nbsp;min) and which reported by Ma et al\u0026nbsp;[24]\u0026nbsp;for unilateral tumor resection in patients with preoperative comorbidities [190 (135–262.5) min]. This suggests that simultaneous bilateral tumor resection may prolong operating duration to some extent, but the degree of prolongation was no more than that observed in unilateral resections performed under other challenging circumstances, such as for large tumors or in patients with preoperative comorbidities.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eIn the present study, postoperative complication rate among the 23 patients was 17.4%, while other literature reported a range of 11.4% to 29.8% for pheochromocytoma surgery [24, 26-28]. And recent report of our center was 14.8% for unilateral tumor resection [24]. Importantly, there were no mortalities or 30-day readmissions in our cases. Cardiovascular events represent the most common postoperative complications following pheochromocytoma surgery [29-32]. Data from our center have consistently reported a low incidence of postoperative complication. For instance, Ma et al. reported a single case of arrhythmia [24] among 438 patients received unilateral resection of PPGLs. Similarly, Lan et al. (n = 350, unilateral resections) reported one case of myocardial infarction [25]. In our study, only one case of transient postoperative myocardial enzyme elevation and electrocardiographic (ECG) abnormalities was observed.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003ePostoperative recovery of our 23 patients demonstrated four characteristics. (1) ICU stay duration was 1 day (IQR 1,1), lower than the 2 days reported in earlier studies [18, 23] and consistent with recent data from our institution [24]. (2) Although Major et al. advocated no drainage after uncomplicated laparoscopic surgery [33], all patients in our study received drainage due to pheochromocytoma’s high bleeding risk, with a median removal time of 3 days (IQR 3,4) and 13% of whom retaining drains \u0026gt;4 days, similar with our center's previous data (9%-20%) [23].\u0026nbsp;(3) Prolonged mechanical ventilation (\u0026gt;24 hours) occurred in 17.4% of our patients, which was similar with our center’s previous report of unilateral resection cohort (20% in Liu et al.,\u0026nbsp;[23]). Furthermore, all patients maintained post-extubating hemodynamic stability without vasopressor support. (4) Postoperative hospitalization (median 7 days, IQR 4,7) and total hospitalization (median 15 days, IQR 13-18) aligned with our institution’s data of unilateral resection\u0026nbsp;[23, 24]. Collectively, these findings indicate that synchronous bilateral resection of PPGLs did not significantly prolong recovery.\u003c/p\u003e\n\u003cp\u003eAs the incidence of bilateral PPGLs is low, reports about the safety of synchronous bilateral resection were rare. In our study, 23 patients’ data were presented detailedly, providing some evidence to help surgical decision-making. However, our findings should be interpreted with caution due to several limitations. First, as a retrospective case series with a modest sample size, statistical analyses and causal inferences have not been implemented, resulting in low evidence strength; Second, all the cases were from a single center, our conclusions may not be applicable to different contexts. Finally, postoperative complications might be underestimated due to incomplete retrospective documentation.\u003c/p\u003e\n\u003cp\u003eIn conclusion, this study reported 23 patients with bilateral pheochromocytomas / paragangliomas who underwent laparoscopic synchronous bilateral tumor resection. Compared with unilateral tumor resection, we did not find the bilateral procedures with more risks of hemorrhage-related complications, hemodynamic fluctuations, or prolonged postoperative recovery.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003eBMI \u0026nbsp; \u0026nbsp; \u0026nbsp; Body Mass Index\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eCT \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;Computed\u0026nbsp;Tomography\u003c/p\u003e\n\u003cp\u003eDA \u0026nbsp; \u0026nbsp; \u0026nbsp; Dopamine\u003c/p\u003e\n\u003cp\u003eDBP \u0026nbsp; \u0026nbsp; \u0026nbsp;Diastolic Blood Pressure\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u003c/p\u003e\n\u003cp\u003eDVT \u0026nbsp; \u0026nbsp; \u0026nbsp;Deep Vein Thrombosis\u003c/p\u003e\n\u003cp\u003eE \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; Epinephrine\u003c/p\u003e\n\u003cp\u003eEBV \u0026nbsp; \u0026nbsp; \u0026nbsp;Estimated Blood Volume\u003c/p\u003e\n\u003cp\u003eHR \u0026nbsp; \u0026nbsp; \u0026nbsp; Heart Rate\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eHGB \u0026nbsp; \u0026nbsp; \u0026nbsp;Hemoglobin \u0026nbsp;\u003c/p\u003e\n\u003cp\u003eIQR \u0026nbsp; \u0026nbsp; \u0026nbsp; Interquartile Range\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eICU \u0026nbsp; \u0026nbsp; \u0026nbsp; Intensive Care Unit\u003c/p\u003e\n\u003cp\u003eNE \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;Norepinephrine\u0026nbsp;\u003c/p\u003e\n\u003cp\u003ePPGLs \u0026nbsp; \u0026nbsp; Pheochromocytomas/Paragangliomas\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eSBP \u0026nbsp; \u0026nbsp; \u0026nbsp; Systolic Blood Pressure \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgments\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe thank the anonymous reviewers for their valuable comments. Responsibility for any remaining errors rests solely with the authors.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eLW Data collection, Statistical analysis, Manuscript. Draft\u003c/p\u003e\n\u003cp\u003eSL Study design.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eXX Statistical analyis.\u003c/p\u003e\n\u003cp\u003eJZ Data collection.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eXY Study design, Statistical analysis, Manuscript revision.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eAll authors have contributed to the article and approved the submitted version.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNo external funding was provided for the planning and conduct of the research or preparation of the manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData availability statement\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe study was reviewed and approved by Peking Union Medical College Hospital (Approval number: I-25PJ1398),\u0026nbsp;Informed consent was obtained from all patients by telephone.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors have no conflicts of interest to declare.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eEmilsson H. High-performance liquid chromatographic determination of cadralazine in human plasma and urine. J Chromatogr. 1988;424(1):119 − 28.http://dx.doi.org/10.1016/s0378-4347(00)81082-8\u003c/li\u003e\n\u003cli\u003eNeumann HPH, Young WF, Jr., Eng C. Pheochromocytoma and Paraganglioma. N Engl J Med. 2019;381(6):552 − 65.http://dx.doi.org/10.1056/NEJMra1806651\u003c/li\u003e\n\u003cli\u003eBerends AMA, Buitenwerf E, de Krijger RR, Veeger N, van der Horst-Schrivers ANA, Links TP, et al. 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Wideochir Inne Tech Maloinwazyjne. 2012;7(1):33 − 9.http://dx.doi.org/10.5114/wiitm.2011.25610\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Pheochromocytoma, Laparoscopic Resection, Bilateral, Perioperative Management, Safety","lastPublishedDoi":"10.21203/rs.3.rs-6979686/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6979686/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e\u003cp\u003eSynchronous resection of bilateral pheochromocytomas/paragangliomas (PPGLs) might increase risk of blood loss, hemodynamic instability, and postoperative complications. However, owing to the low incidence of bilateral PPGLs, evidence of safety for these surgeries is not enough, with only case reports available. This study reported a series of bilateral PPGLs case. All the patients received synchronous laparoscopic resection of tumors.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e\u003cp\u003ePatients underwent synchronous laparoscopic resection of bilateral pheochromocytoma were included. Clinical data including preoperative variables, intraoperative blood loss and transfusion, and postoperative recovery were collected.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e\u003cp\u003eA total of 23 patients were collected. Median intraoperative blood loss was 200 ml (IQR 50, 350), with blood loss/estimated blood volume (EBV) ratio of 3.2%. No allogeneic transfusion required intraoperatively, and the postoperative allogeneic transfusion rate was 4.3%. 82.6% (19/23), 30.4% (7/23), and 17.4% (4/23) of patients required low-dose norepinephrine support at the end of operation, during ICU observation, and at 24 hours respectively. The incidence of postoperative mechanical ventilation duration\u0026thinsp;\u0026gt;\u0026thinsp;24 h and Foley catheterization duration\u0026thinsp;\u0026gt;\u0026thinsp;4 days was 17.4% and 13% respectively. ICU and hospital stay duration was 1 day (IQR 1, 1) and 7 days (IQR 4, 7) respectively. Postoperative complication rate was 17.4%. No postoperative mortality and 30-day occured.\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e\u003cp\u003eCompared with unilateral tumor resection, we did not find synchronous resection of bilateral PPGLs with more risks of hemorrhage-related complications, hemodynamic fluctuations, or prolonged postoperative recovery.\u003c/p\u003e","manuscriptTitle":"Safety of Synchronous Laparoscopic Resection of Bilateral Pheochromocytomas/Paragangliomas: A Single-Center Retrospective Study","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-08-07 10:27:45","doi":"10.21203/rs.3.rs-6979686/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"3a15ae0e-a12b-46df-bf8a-7133f6631da9","owner":[],"postedDate":"August 7th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2026-03-25T08:56:26+00:00","versionOfRecord":[],"versionCreatedAt":"2025-08-07 10:27:45","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-6979686","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6979686","identity":"rs-6979686","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}