Laparoscopy-assisted partial cecum resection vs. ileocecal resection for non-malignant appendiceal neoplasms

Laparoscopy-assisted partial cecum resection vs. ileocecal resection for non-malignant appendiceal neoplasms | 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 Laparoscopy-assisted partial cecum resection vs. ileocecal resection for non-malignant appendiceal neoplasms Kentaro Abe, Hiroaki Nozawa, Kazuhito Sasaki, Koji Murono, Shigenobu Emoto, and 7 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6903380/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 Purpose Preoperative pathological diagnosis of appendiceal tumors is difficult due to their anatomical nature. Although lymph node metastasis is rare in low-grade appendiceal mucinous neoplasms (LAMN), there is a risk of a positive surgical margin by appendectomy. Partial cecum resection is considered an option to obtain negative resection margins for LAMN; however, the benefits of this procedure via a laparoscopic approach remain unclear. Methods We retrospectively analyzed patients who underwent laparoscopy-assisted partial cecum resection (Lap-Ce) or ileocecum resection (Lap-ICR) for primary appendiceal tumors at our department. An intraoperative pathological diagnosis was requested at the surgeon’s discretion. Clinicopathological factors and surgical outcomes were compared among the two groups. Results Intraoperative pathological consultations were conducted for 86% (12 of 14 patients) of the Lap-Ce group and 4% (1 of 27 patients) of the Lap-ICR group. Fewer trocars (median: 3) were used in the Lap-Ce group than in the Lap-ICR group (5 trocars in all patients, p < 0.0001). The Lap-Ce group had a shorter operative time (median: 113 vs. 197 min, p < 0.0001), less blood loss (median: 1 vs. 32 mL, p < 0.0001), and a shorter time to the first bowel movement than the Lap-ICR group (2 vs. 3 days, p = 0.049). There was no recurrence in either group. Conclusion Lap-Ce was less invasive than Lap-ICR as assessed by perioperative variables. Therefore, Lap-Ce is considered to be useful as a primary surgical procedure for clinically benign lesions. appendiceal tumour low-grade appendiceal mucinous neoplasm laparoscopic surgery partial cecum resection surgical outcome Figures Figure 1 Figure 2 Figure 3 Background Appendiceal tumors are rare in clinical practice, accounting for only 4% of intestinal tumors [ 1 , 2 ]. According to the Peritoneal Surface Oncology Group International classification from 2015, epithelial neoplasia of the appendix is classified into low-grade appendiceal mucinous neoplasm (LAMN), high-grade appendiceal mucinous neoplasm, serrated polyp, adenoma, adenocarcinoma, and poorly differentiated adenocarcinoma with signet ring cells [ 3 ]. Previous studies suggested that the incidence of primary appendiceal neoplasms has increased in the last few decades [ 4 – 6 ]. In clinical practice, appendiceal tumors may be misdiagnosed as appendicitis, mucin accumulation, regenerative changes, and fibrosis. When the lesion is located at the body or tip of the appendix, it is more difficult to make a definitive diagnosis by endoscopic biopsy. Therefore, a preoperative diagnosis in terms of both histology and location is crucial for selecting the treatment strategy for appendiceal tumors. When a histological diagnosis cannot be made preoperatively, an intraoperative consultation to the pathology unit may be very useful. Surgical procedures for appendiceal tumors include right hemicolectomy, ileocecal resection, partial cecum resection, and appendectomy. If malignancy is suspected preoperatively, lymph node dissection needs to be planned. LAMN is associated with a very low risk of lymph node involvement even when it extensively disseminates to the peritoneum [ 7 , 8 ], whereas the primary tumor occasionally extends near to or beyond the appendiceal orifice. The Chicago Consensus Working Group recommends appendectomy as the first-line treatment for LAMN, with additional resection, such as colectomy, in cases with a positive margin [ 9 ]. In this context, a previous study on additional cecum resection for margin-positive appendiceal adenoma or LAMN after appendectomy in six patients revealed no residual tumor [ 10 ], highlighting the relevance of this procedure as primary surgery for benign appendiceal tumors. However, the surgical and pathological outcomes of cecum resection for appendiceal tumors have not yet been compared with those of ileocecal resection. Based on the aforementioned knowledge, we introduced a minimally invasive approach to partial cecum resection for appendiceal tumors suspected of being LAMN at our department in 2018. The present study investigated the usefulness of partial cecum resection via a laparoscopic approach for clinically diagnosed LAMN. Materials and Methods Study population We included patients who underwent laparoscopy-assisted partial cecum resection (Lap-Ce) or laparoscopy-assisted ileocecum resection (Lap-ICR) for primary appendiceal tumors at our department between January 2008 and December 2023. Patients with a preoperative diagnosis of malignancy were excluded. In principle, a preoperative diagnosis was made by a histological evaluation using endoscopic biopsy. All patients underwent computed tomography (CT) before surgery. In addition, magnetic resonance imaging and/or 18 F-fluorodeoxyglucose with positron emission tomography (FDG-PET)/CT were performed based on the discretion of the attending surgeon. Surgical treatment and collection of clinicopathological data Laparoscopic surgery was performed by a team of board-certified expert surgeons. The position of laparoscopic ports is shown in Fig. 1 . At our department, we placed two trocars in the left upper and lower quadrants for the operator in addition to a camera port at the umbilicus in Lap-Ce. In contrast, we placed two trocars for the operator in the left upper and lower quadrants, and the other trocars in the right upper and lower quadrants for the assistant in Lap-ICR. Additional trocars were placed for both procedures, if necessary. After a pneumoperitoneum was created, the cecum and lower segment of the ascending colon were mobilized in Lap-Ce. A linear stapler was used for resection to ensure that a sufficient distance from the appendiceal tumor was maintained (Fig. 2 a). In Lap-ICR, the ileocolic artery and vein were ligated at the roots, and lymph nodes were dissected (Fig. 2 b). The right colonic segment was mobilized with the take-down of the hepatic flexure. After the ileocecum was removed, the bowel was typically reconstructed extracorporeally by end-to-side anastomosis of the ileum and ascending colon. A rapid intraoperative pathological diagnosis was requested at the discretion of the surgeon while intraabdominal lavage was being performed. Clinicopathological variables, such as age, sex, body mass index, symptoms, intraabdominal adhesion, operative time, intraoperative blood loss, postoperative morbidities graded by the Clavien–Dindo classification [ 11 ], intraoperative pathological diagnosis, and recurrence, were retrieved from the medical and pathological records of patients. Statistical analysis All analyses were performed using JMP Pro 17.2 (SAS Institute Inc., Cary, NC, USA). The Wilcoxon rank-sum test and Fisher’s exact test were used where appropriate. All reported p -values were two-tailed and those < 0.05 were considered to be significant. Results Patient characteristics During the study period, 52 patients underwent laparoscopic surgery for primary appendiceal tumors. The flow chart for selecting patients is shown in Fig. 3 . After excluding 11 patients who underwent laparoscopic appendix resection or were preoperatively diagnosed with malignancy, 14 were classified into the Lap-Ce group and 27 into the Lap-ICR group. The characteristics of the two patient groups are summarized in Table 1 . The entire cohort comprised 23 males and 18 females, and the median age of patients was 57 years old. In the Lap-Ce group, six patients (43%) had preoperative symptoms, with abdominal pain being the most common (29%). Table 1 Clinical characteristics in patients who underwent surgery for non-malignant appendiceal neoplasms Variables Lap-Ce (n = 14) Lap-ICR (n = 27) p -value Age, years 54 (34–85) 58 (34–83) 0.18 Male 9 (64%) 14 (52%) 0.52 Body mass index, kg/m 2 24.5 (17.1–30.0) 24.6 (16.5–42.7) 0.63 Symptoms 6 (43%) 10 (37%) 0.75 Abdominal pain 4 (29%) 5 (19%) Back pain 0 (0%) 1 (4%) Melena 1 (7%) 2 (7%) Diarrhea 1 (7%) 1 (4%) Palpable mass 0 (0%) 1 (4%) Abdominal discomfort 0 (0%) 2 (7%) Tumor diameter on CT scan, mm 15 (5–51) 20 (7-124) 0.34 Values are presented as the number of patients (%) or median (interquartile range). Lap-Ce: Laparoscopy-assisted cecal resection; Lap-ICR: Laparoscopy-assisted ileocecal resection; CT: Computed tomography Surgical outcomes Comparative surgical outcomes between the Lap-Ce and Lap-ICR groups are shown in Table 2 . In the Lap-Ce group, eight patients (57%) underwent laparoscopic surgery performed with three trocars, whereas five trocars were placed in all patients in the Lap-ICR group ( p < 0.0001). The operative time was shorter in the Lap-Ce group (median: 113 min) than in the Lap-ICR group (median: 197 min, p < 0.0001). Intraoperative blood loss was also smaller in the Lap-Ce group (median: 1 mL vs. 32 mL, p < 0.0001). Moreover, the median time to the first bowel movement was shorter in the Lap-Ce group than in the Lap-ICR group (2 days vs. 3 days, p = 0.049). The frequency of complications of Clavien-Dindo classification 2 or higher was similar between the two groups ( p = 0.62). The postoperative hospital stay was shorter in the Lap-Ce group (median: 6 days vs. 11 days, p < 0.0001). Table 2 Surgical outcomes in patients with non-malignant appendiceal neoplasms Variables Lap-Ce (n = 14) Lap-ICR (n = 27) p -value Number of laparoscopic trocars < .0001 3 trocars 8 (57%) 0 (0%) 4 trocars 5 (36%) 0 (0%) 5 trocars 1 (7%) 27(100%) Length of umbilical incision, mm 12 (12–30) 35 (12–60) < .0001 Intraoperative pathological consultation 12 (86%) 1 (4%) < .0001 Intraabdominal adhesion 8 (57%) 7 (26%) 0.086 Placement of peritoneal drainage tube 0 (0%) 0 (0%) 1.00 Operative time, min 113 (73–206) 197 (94–367) < .0001 Intraoperative blood loss, ml 1 (0–10) 32 (1-200) < .0001 Time to postoperative bowel movement, day 2 (1–3) 3 (1–6) 0.049 Complications (CD ≧ grade 2) 1 (7%) 3 (11%) 0.62 Bowel obstruction 1 (7%) 0 (0%) Hepatic dysfunction 0 (0%) 1 (4%) Postoperative hemorrhage 0 (0%) 1 (4%) Surgical site infection 0 (0%) 1 (4%) Postoperative hospital stay, day 6 (4–16) 11 (7–20) < .0001 Values are presented as the number of patients (%) or median (interquartile range). Lap-Ce: laparoscopic-assisted partial cecum resection; Lap-ICR: laparoscopic-assisted ileocecal resection; CD: Clavien-Dindo classification Preoperative, intraoperative, and final diagnoses A histological diagnosis was made prior to the index surgery in 12 patients. Of these, seven patients underwent preoperative biopsy, the findings of which suggested benign lesions; however, none were diagnosed with LAMN. Lap-ICR was selected for a patient with neurofibromatosis as additional resection after appendectomy for LAMN because of a positive resection margin. Intraoperative pathological consultations were conducted for 12 patients (86%) in the Lap-Ce group and only one patient (4%) in the Lap-ICR group ( p < 0.0001, Table 2 ). In the Lap-Ce group, LAMN was correctly diagnosed in one patient, while benign lesions, not otherwise specified, were suspected in the remaining 11. In one patient in the Lap-ICR group, Lap-Ce was initially planned with the intraoperative diagnosis of a benign lesion. However, the surgical procedure was changed to Lap-ICR due to dense adhesions around the ileocecal area in this patient. Final histological diagnoses are summarized in Table 3 . In the Lap-Ce group, all 14 patients were diagnosed with benign lesions, with LAMN being the most common (36%). A number of diagnoses were made in other patients, including appendicitis, a sessile serrated lesion, endometriosis, a mucocele, and ruptured diverticular disease. In the Lap-ICR group, one patient preoperatively diagnosed with tubulovillous adenoma by endoscopic biopsy had appendiceal adenocarcinoma of 70 mm in size that directly invaded the lateral wall of the cecum; the primary tumor was composed of papillotubular adenocarcinoma combined with a mucinous component, although there was no lymph node involvement. The remaining 26 patients had benign lesions, with LAMN being the most common (52%). Other diagnoses included appendicitis (6 patients) and diverticulitis (3 patients). No positive resection margins were documented in any case of a neoplasm in either group. Table 3 Histological findings at final diagnosis Lap-Ce (n = 14) Lap-ICR (n = 27) Benign 14 (100%) Benign 26 (96%) LAMN 5 (36%) LAMN 14 (52%) Appendicitis 4 (29%) Appendicitis 6 (22%) SSL 2 (14%) Diverticulitis 3 (11%) Ruptured diverticular disease 1 (7%) Ruptured diverticular disease 1 (4%) Endometriosis 1 (7%) Abscess 1 (4%) Mucocele 1 (7%) Submucosal lipomatosis 1 (4%) Malignant 0 (0%) Malignant 1 (4%) Adenocarcinoma 1 (4%) Lap-Ce: laparoscopic-assisted partial cecum resection; Lap-ICR: laparoscopic-assisted ileocecal resection; LAMN: Low-grade appendiceal mucinous neoplasms; SSL: Sessile serrated lesion Discussion There have been several case reports on the feasibility or safety of Lap-Ce for appendiceal tumors [ 12 , 13 ]. However, they did not compare surgical outcomes with those of other surgical procedures. This is the first study to compare Lap-Ce and Lap-ICR for clinical LAMN in terms of perioperative outcomes, postoperative recovery, and pathological aspects. Appendiceal tumors including LAMN are difficult to correctly diagnose before surgery. CT is commonly used as a preoperative imaging tool for appendiceal tumors. Previous studies reported that irregularities in the tumor wall on CT and elevated maximum standard uptake values on PET/CT were valuable findings for a differential diagnosis between appendiceal mucocele with mucinous adenocarcinoma and other pathologies [ 14 , 15 ]. Other studies suggested that radiological and preoperative pathological findings on appendiceal neoplasms may be prone to overinterpretation [ 16 – 18 ]. In the present study, a preoperative diagnosis was reached based on imaging findings in many patients because a preoperative histological diagnosis was not available. Lesions were not neoplastic in 46% of patients in the final diagnosis, suggesting the difficulties associated with correctly diagnosing an appendiceal tumor before surgery. Minimal mobilization of the ileocecal segment and no anastomosis may have contributed to the shorter operative time and faster recovery of bowel function in the Lap-Ce group. On the other hand, Lap-Ce has the disadvantage of requiring more time when an intraoperative pathological consultation is conducted. If the intraoperative pathological diagnosis indicates malignancy, the surgical procedure is changed to ileocecal resection with lymph node dissection. In the present study, there were no cases of malignancy in the Lap-Ce group. Therefore, in the future, it may be possible to complete all surgical procedures, including wound closure, before extubation while a pathological examination confirms a benign lesion. There are several limitations that need to be addressed. Our cohort comprised a small number of patients because appendiceal tumors are rare. Since data on patients were retrospectively analyzed by the as-treated approach, the Lap-ICR group included a patient who was originally scheduled to undergo Lap-Ce. Furthermore, Lap-Ce was performed on more recently treated patients at our department. Moreover, the follow-up period may not have been sufficiently long to evaluate postoperative recurrence. An intraoperative pathological diagnosis may not be applied as routine clinical practice in all hospitals. However, Lap-Ce may be a useful procedure, requiring a markedly shorter operative time without an intraoperative pathological consultation under the condition that the patient is informed about the risk of bailout lymphadenectomy in the future depending on the final diagnosis of malignancy. Another limitation is that Lap-Ce was not compared with laparoscopic appendectomy for clinical LAMN in terms of surgical margins and operative time. In the present study, Lap-Ce was less invasive than Lap-ICR, as evidenced by the use of fewer trocars, shorter operative time, and faster postoperative recovery. The results obtained suggest the potential of Lap-Ce as the primary surgical procedure for clinically benign lesions. Declarations Acknowledgments We would like to thank Medical English Service (Kyoto, Japan) for their assistance with editing this manuscript. Their expertise in improving the clarity and language of our manuscript was invaluable. Author contributions Hiroaki Nozawa contributed to the study conception and design. Data collection was performed by Kentaro Abe and Hiroaki Nozawa. Data analysis was done by all authors. The first draft of the manuscript was written by Kentaro Abe, and the remaining authors made critical comments on it. All authors read and approved the final manuscript. Compliance with Ethical Standards Disclosure of potential conflicts of Interest Kentaro Abe, Hiroaki Nozawa, Kazuhito Sasaki, Koji Murono, Shigenobu Emoto, Yuichiro Yokoyama, Yuzo Nagai, Takahide Shinagawa, Yuichi Tachikawa, Satoshi Okada, Tetsuo Ushiku, and Soichiro Ishihara have no conflicts of interest to disclose. Funding No funding was received for conducting this study. Ethics approval The present study was approved by the Ethics Committees of the University of Tokyo (No. 3252- [17]). This study was performed in line with the principles of the 1964 Declaration of Helsinki and its later amendments. Consent to participate Informed consent was obtained from all individual participants included in the study. References Siddharthan RV, Byrne RM, Dewey E, Martindale RG, Gilbert EW, Tsikitis VL (2019) Appendiceal cancer masked as inflammatory appendicitis in the elderly, not an uncommon presentation (Surveillance Epidemiology and End Results (SEER)-Medicare Analysis. 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Mod Pathol 32:988–996 Valasek MA, Thung I, Gollapalle E, Hodkoff AA, Kelly KJ, Baumgartner JM, Vavinskaya V, Lin GY, Tipps AP, Hosseini MV, LowyAM (2017) Overinterpretation is common in pathological diagnosis of appendix cancer during patient referral for oncologic care. PLoS ONE 12:e0179216 Xiao J, Li P, Liu W (2021) Analysis of Clinical Characteristics of Low-Grade Appendiceal Mucinous Neoplasm (LAMN): A Retrospective Cohort Study of 51 LAMN Patients. J Invest Surg 34:721–727 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-6903380","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":473573881,"identity":"de75723f-2816-4d76-a856-482e9d8c7021","order_by":0,"name":"Kentaro Abe","email":"","orcid":"","institution":"Graduate school of Medicine, The University of Tokyo","correspondingAuthor":false,"prefix":"","firstName":"Kentaro","middleName":"","lastName":"Abe","suffix":""},{"id":473573884,"identity":"7912d676-c897-40ef-9caa-a1194af79ee2","order_by":1,"name":"Hiroaki 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Tokyo","correspondingAuthor":false,"prefix":"","firstName":"Soichiro","middleName":"","lastName":"Ishihara","suffix":""}],"badges":[],"createdAt":"2025-06-16 08:38:20","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6903380/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6903380/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":85172965,"identity":"32a4fc84-cdd2-4c3b-807e-0db64c136f6d","added_by":"auto","created_at":"2025-06-23 05:54:41","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":160057,"visible":true,"origin":"","legend":"\u003cp\u003eSchematic positions of the camera port and trocars for Lap-Ce (a) and Lap-ICR (b) at our department\u003c/p\u003e","description":"","filename":"Fig.1.png","url":"https://assets-eu.researchsquare.com/files/rs-6903380/v1/b420adaa85cfaf3dd1eb2c13.png"},{"id":85172969,"identity":"3744911d-f16c-4ec4-812e-89c7373253c5","added_by":"auto","created_at":"2025-06-23 05:54:41","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":228997,"visible":true,"origin":"","legend":"\u003cp\u003eIllustrated procedures of Lap-Ce (a) and Lap-ICR (b). Dashed lines indicate transection of the bowel and the area of lymph node dissection T/C: transverse colon; A/C: ascending colon; C: cecum; SMA: superior mesenteric artery; SMV: superior mesenteric vein; ICA: ileocolic artery; ICV: ileocolic vein\u003c/p\u003e","description":"","filename":"Fig.2.png","url":"https://assets-eu.researchsquare.com/files/rs-6903380/v1/8f3ce96db0d346ad5818cbc0.png"},{"id":85172970,"identity":"3eb08813-ee73-4ce1-9fc0-5712ab70446d","added_by":"auto","created_at":"2025-06-23 05:54:41","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":749189,"visible":true,"origin":"","legend":"\u003cp\u003eFlow chart for selecting patients\u003c/p\u003e","description":"","filename":"Fig.3.png","url":"https://assets-eu.researchsquare.com/files/rs-6903380/v1/727c09b6c451835da0e3e0e9.png"},{"id":86915939,"identity":"5bcde791-8e54-49f1-ba8f-962add52a324","added_by":"auto","created_at":"2025-07-17 06:32:09","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1863109,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6903380/v1/21acaea0-67ea-462c-813b-3ce67e1a2c52.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Laparoscopy-assisted partial cecum resection vs. ileocecal resection for non-malignant appendiceal neoplasms","fulltext":[{"header":"Background","content":"\u003cp\u003eAppendiceal tumors are rare in clinical practice, accounting for only 4% of intestinal tumors [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. According to the Peritoneal Surface Oncology Group International classification from 2015, epithelial neoplasia of the appendix is classified into low-grade appendiceal mucinous neoplasm (LAMN), high-grade appendiceal mucinous neoplasm, serrated polyp, adenoma, adenocarcinoma, and poorly differentiated adenocarcinoma with signet ring cells [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. Previous studies suggested that the incidence of primary appendiceal neoplasms has increased in the last few decades [\u003cspan additionalcitationids=\"CR5\" citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. In clinical practice, appendiceal tumors may be misdiagnosed as appendicitis, mucin accumulation, regenerative changes, and fibrosis. When the lesion is located at the body or tip of the appendix, it is more difficult to make a definitive diagnosis by endoscopic biopsy. Therefore, a preoperative diagnosis in terms of both histology and location is crucial for selecting the treatment strategy for appendiceal tumors. When a histological diagnosis cannot be made preoperatively, an intraoperative consultation to the pathology unit may be very useful. Surgical procedures for appendiceal tumors include right hemicolectomy, ileocecal resection, partial cecum resection, and appendectomy. If malignancy is suspected preoperatively, lymph node dissection needs to be planned. LAMN is associated with a very low risk of lymph node involvement even when it extensively disseminates to the peritoneum [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e], whereas the primary tumor occasionally extends near to or beyond the appendiceal orifice. The Chicago Consensus Working Group recommends appendectomy as the first-line treatment for LAMN, with additional resection, such as colectomy, in cases with a positive margin [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. In this context, a previous study on additional cecum resection for margin-positive appendiceal adenoma or LAMN after appendectomy in six patients revealed no residual tumor [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e], highlighting the relevance of this procedure as primary surgery for benign appendiceal tumors. However, the surgical and pathological outcomes of cecum resection for appendiceal tumors have not yet been compared with those of ileocecal resection.\u003c/p\u003e \u003cp\u003eBased on the aforementioned knowledge, we introduced a minimally invasive approach to partial cecum resection for appendiceal tumors suspected of being LAMN at our department in 2018. The present study investigated the usefulness of partial cecum resection via a laparoscopic approach for clinically diagnosed LAMN.\u003c/p\u003e"},{"header":"Materials and Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eStudy population\u003c/h2\u003e \u003cp\u003eWe included patients who underwent laparoscopy-assisted partial cecum resection (Lap-Ce) or laparoscopy-assisted ileocecum resection (Lap-ICR) for primary appendiceal tumors at our department between January 2008 and December 2023. Patients with a preoperative diagnosis of malignancy were excluded. In principle, a preoperative diagnosis was made by a histological evaluation using endoscopic biopsy. All patients underwent computed tomography (CT) before surgery. In addition, magnetic resonance imaging and/or \u003csup\u003e18\u003c/sup\u003eF-fluorodeoxyglucose with positron emission tomography (FDG-PET)/CT were performed based on the discretion of the attending surgeon.\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eSurgical treatment and collection of clinicopathological data\u003c/h3\u003e\n\u003cp\u003eLaparoscopic surgery was performed by a team of board-certified expert surgeons. The position of laparoscopic ports is shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. At our department, we placed two trocars in the left upper and lower quadrants for the operator in addition to a camera port at the umbilicus in Lap-Ce. In contrast, we placed two trocars for the operator in the left upper and lower quadrants, and the other trocars in the right upper and lower quadrants for the assistant in Lap-ICR. Additional trocars were placed for both procedures, if necessary. After a pneumoperitoneum was created, the cecum and lower segment of the ascending colon were mobilized in Lap-Ce. A linear stapler was used for resection to ensure that a sufficient distance from the appendiceal tumor was maintained (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003ea). In Lap-ICR, the ileocolic artery and vein were ligated at the roots, and lymph nodes were dissected (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eb). The right colonic segment was mobilized with the take-down of the hepatic flexure. After the ileocecum was removed, the bowel was typically reconstructed extracorporeally by end-to-side anastomosis of the ileum and ascending colon. A rapid intraoperative pathological diagnosis was requested at the discretion of the surgeon while intraabdominal lavage was being performed.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eClinicopathological variables, such as age, sex, body mass index, symptoms, intraabdominal adhesion, operative time, intraoperative blood loss, postoperative morbidities graded by the Clavien\u0026ndash;Dindo classification [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e], intraoperative pathological diagnosis, and recurrence, were retrieved from the medical and pathological records of patients.\u003c/p\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003eStatistical analysis\u003c/h2\u003e \u003cp\u003eAll analyses were performed using JMP Pro 17.2 (SAS Institute Inc., Cary, NC, USA). The Wilcoxon rank-sum test and Fisher\u0026rsquo;s exact test were used where appropriate. All reported \u003cem\u003ep\u003c/em\u003e-values were two-tailed and those\u0026thinsp;\u0026lt;\u0026thinsp;0.05 were considered to be significant.\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cdiv id=\"Sec7\" class=\"Section2\"\u003e \u003ch2\u003ePatient characteristics\u003c/h2\u003e \u003cp\u003eDuring the study period, 52 patients underwent laparoscopic surgery for primary appendiceal tumors. The flow chart for selecting patients is shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e. After excluding 11 patients who underwent laparoscopic appendix resection or were preoperatively diagnosed with malignancy, 14 were classified into the Lap-Ce group and 27 into the Lap-ICR group. The characteristics of the two patient groups are summarized in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. The entire cohort comprised 23 males and 18 females, and the median age of patients was 57 years old. In the Lap-Ce group, six patients (43%) had preoperative symptoms, with abdominal pain being the most common (29%).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eClinical characteristics in patients who underwent surgery for non-malignant appendiceal neoplasms\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVariables\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eLap-Ce\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;14)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eLap-ICR\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;27)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cem\u003ep\u003c/em\u003e-value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAge, years\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e54 (34\u0026ndash;85)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e58 (34\u0026ndash;83)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.18\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e9 (64%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e14 (52%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.52\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBody mass index, kg/m\u003csup\u003e2\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e24.5 (17.1\u0026ndash;30.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e24.6 (16.5\u0026ndash;42.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.63\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSymptoms\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e6 (43%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e10 (37%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.75\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAbdominal pain\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e4 (29%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e5 (19%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBack pain\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0 (0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1 (4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMelena\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1 (7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2 (7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDiarrhea\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1 (7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1 (4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePalpable mass\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0 (0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1 (4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAbdominal discomfort\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0 (0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2 (7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTumor diameter on CT scan, mm\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e15 (5\u0026ndash;51)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e20 (7-124)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.34\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"4\"\u003eValues are presented as the number of patients (%) or median (interquartile range).\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"4\"\u003eLap-Ce: Laparoscopy-assisted cecal resection; Lap-ICR: Laparoscopy-assisted ileocecal resection; CT: Computed tomography\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003eSurgical outcomes\u003c/h2\u003e \u003cp\u003eComparative surgical outcomes between the Lap-Ce and Lap-ICR groups are shown in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e. In the Lap-Ce group, eight patients (57%) underwent laparoscopic surgery performed with three trocars, whereas five trocars were placed in all patients in the Lap-ICR group (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.0001). The operative time was shorter in the Lap-Ce group (median: 113 min) than in the Lap-ICR group (median: 197 min, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.0001). Intraoperative blood loss was also smaller in the Lap-Ce group (median: 1 mL vs. 32 mL, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.0001). Moreover, the median time to the first bowel movement was shorter in the Lap-Ce group than in the Lap-ICR group (2 days vs. 3 days, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.049). The frequency of complications of Clavien-Dindo classification 2 or higher was similar between the two groups (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.62). The postoperative hospital stay was shorter in the Lap-Ce group (median: 6 days vs. 11 days, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.0001).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eSurgical outcomes in patients with non-malignant appendiceal neoplasms\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVariables\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eLap-Ce\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;14)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eLap-ICR\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;27)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cem\u003ep\u003c/em\u003e-value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNumber of laparoscopic trocars\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;.0001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e3 trocars\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e8 (57%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0 (0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e4 trocars\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e5 (36%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0 (0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e5 trocars\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1 (7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e27(100%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLength of umbilical incision, mm\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e12 (12\u0026ndash;30)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e35 (12\u0026ndash;60)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;.0001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIntraoperative pathological consultation\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e12 (86%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1 (4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;.0001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIntraabdominal adhesion\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e8 (57%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e7 (26%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.086\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePlacement of peritoneal drainage tube\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0 (0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0 (0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.00\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOperative time, min\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e113 (73\u0026ndash;206)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e197 (94\u0026ndash;367)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;.0001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIntraoperative blood loss, ml\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1 (0\u0026ndash;10)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e32 (1-200)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;.0001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTime to postoperative bowel movement, day\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2 (1\u0026ndash;3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3 (1\u0026ndash;6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.049\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eComplications (CD\u0026thinsp;≧\u0026thinsp;grade 2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1 (7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3 (11%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.62\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBowel obstruction\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1 (7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0 (0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHepatic dysfunction\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0 (0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1 (4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePostoperative hemorrhage\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0 (0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1 (4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSurgical site infection\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0 (0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1 (4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePostoperative hospital stay, day\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e6 (4\u0026ndash;16)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e11 (7\u0026ndash;20)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;.0001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"4\"\u003eValues are presented as the number of patients (%) or median (interquartile range).\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"4\"\u003eLap-Ce: laparoscopic-assisted partial cecum resection; Lap-ICR: laparoscopic-assisted ileocecal resection; CD: Clavien-Dindo classification\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003ePreoperative, intraoperative, and final diagnoses\u003c/h3\u003e\n\u003cp\u003eA histological diagnosis was made prior to the index surgery in 12 patients. Of these, seven patients underwent preoperative biopsy, the findings of which suggested benign lesions; however, none were diagnosed with LAMN. Lap-ICR was selected for a patient with neurofibromatosis as additional resection after appendectomy for LAMN because of a positive resection margin.\u003c/p\u003e \u003cp\u003eIntraoperative pathological consultations were conducted for 12 patients (86%) in the Lap-Ce group and only one patient (4%) in the Lap-ICR group (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.0001, Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). In the Lap-Ce group, LAMN was correctly diagnosed in one patient, while benign lesions, not otherwise specified, were suspected in the remaining 11. In one patient in the Lap-ICR group, Lap-Ce was initially planned with the intraoperative diagnosis of a benign lesion. However, the surgical procedure was changed to Lap-ICR due to dense adhesions around the ileocecal area in this patient.\u003c/p\u003e \u003cp\u003eFinal histological diagnoses are summarized in Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e. In the Lap-Ce group, all 14 patients were diagnosed with benign lesions, with LAMN being the most common (36%). A number of diagnoses were made in other patients, including appendicitis, a sessile serrated lesion, endometriosis, a mucocele, and ruptured diverticular disease. In the Lap-ICR group, one patient preoperatively diagnosed with tubulovillous adenoma by endoscopic biopsy had appendiceal adenocarcinoma of 70 mm in size that directly invaded the lateral wall of the cecum; the primary tumor was composed of papillotubular adenocarcinoma combined with a mucinous component, although there was no lymph node involvement. The remaining 26 patients had benign lesions, with LAMN being the most common (52%). Other diagnoses included appendicitis (6 patients) and diverticulitis (3 patients). No positive resection margins were documented in any case of a neoplasm in either group.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eHistological findings at final diagnosis\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003eLap-Ce (n\u0026thinsp;=\u0026thinsp;14)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e \u003cp\u003eLap-ICR (n\u0026thinsp;=\u0026thinsp;27)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBenign\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e14 (100%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eBenign\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e26 (96%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLAMN\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e5 (36%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eLAMN\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e14 (52%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAppendicitis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e4 (29%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eAppendicitis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e6 (22%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSSL\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2 (14%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eDiverticulitis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e3 (11%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRuptured diverticular disease\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1 (7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eRuptured diverticular disease\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1 (4%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eEndometriosis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1 (7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eAbscess\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1 (4%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMucocele\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1 (7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eSubmucosal lipomatosis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1 (4%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMalignant\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0 (0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eMalignant\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1 (4%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eAdenocarcinoma\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1 (4%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"4\"\u003eLap-Ce: laparoscopic-assisted partial cecum resection; Lap-ICR: laparoscopic-assisted ileocecal resection; LAMN: Low-grade appendiceal mucinous neoplasms; SSL: Sessile serrated lesion\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThere have been several case reports on the feasibility or safety of Lap-Ce for appendiceal tumors [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e, \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. However, they did not compare surgical outcomes with those of other surgical procedures. This is the first study to compare Lap-Ce and Lap-ICR for clinical LAMN in terms of perioperative outcomes, postoperative recovery, and pathological aspects.\u003c/p\u003e \u003cp\u003eAppendiceal tumors including LAMN are difficult to correctly diagnose before surgery. CT is commonly used as a preoperative imaging tool for appendiceal tumors. Previous studies reported that irregularities in the tumor wall on CT and elevated maximum standard uptake values on PET/CT were valuable findings for a differential diagnosis between appendiceal mucocele with mucinous adenocarcinoma and other pathologies [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e, \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]. Other studies suggested that radiological and preoperative pathological findings on appendiceal neoplasms may be prone to overinterpretation [\u003cspan additionalcitationids=\"CR17\" citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. In the present study, a preoperative diagnosis was reached based on imaging findings in many patients because a preoperative histological diagnosis was not available. Lesions were not neoplastic in 46% of patients in the final diagnosis, suggesting the difficulties associated with correctly diagnosing an appendiceal tumor before surgery.\u003c/p\u003e \u003cp\u003eMinimal mobilization of the ileocecal segment and no anastomosis may have contributed to the shorter operative time and faster recovery of bowel function in the Lap-Ce group. On the other hand, Lap-Ce has the disadvantage of requiring more time when an intraoperative pathological consultation is conducted. If the intraoperative pathological diagnosis indicates malignancy, the surgical procedure is changed to ileocecal resection with lymph node dissection. In the present study, there were no cases of malignancy in the Lap-Ce group. Therefore, in the future, it may be possible to complete all surgical procedures, including wound closure, before extubation while a pathological examination confirms a benign lesion.\u003c/p\u003e \u003cp\u003eThere are several limitations that need to be addressed. Our cohort comprised a small number of patients because appendiceal tumors are rare. Since data on patients were retrospectively analyzed by the as-treated approach, the Lap-ICR group included a patient who was originally scheduled to undergo Lap-Ce. Furthermore, Lap-Ce was performed on more recently treated patients at our department. Moreover, the follow-up period may not have been sufficiently long to evaluate postoperative recurrence. An intraoperative pathological diagnosis may not be applied as routine clinical practice in all hospitals. However, Lap-Ce may be a useful procedure, requiring a markedly shorter operative time without an intraoperative pathological consultation under the condition that the patient is informed about the risk of bailout lymphadenectomy in the future depending on the final diagnosis of malignancy. Another limitation is that Lap-Ce was not compared with laparoscopic appendectomy for clinical LAMN in terms of surgical margins and operative time.\u003c/p\u003e \u003cp\u003eIn the present study, Lap-Ce was less invasive than Lap-ICR, as evidenced by the use of fewer trocars, shorter operative time, and faster postoperative recovery. The results obtained suggest the potential of Lap-Ce as the primary surgical procedure for clinically benign lesions.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cem\u003eAcknowledgments\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eWe would like to thank Medical English Service (Kyoto, Japan) for their assistance with editing this manuscript. Their expertise in improving the clarity and language of our manuscript was invaluable.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eAuthor contributions\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eHiroaki Nozawa contributed to the study conception and design. Data collection was performed by Kentaro Abe and Hiroaki Nozawa. Data analysis was done by all authors. The first draft of the manuscript was written by Kentaro Abe, and the remaining authors made critical comments on it. All authors read and approved the final manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eCompliance with Ethical Standards\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eDisclosure of potential conflicts of Interest\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eKentaro Abe, Hiroaki Nozawa, Kazuhito Sasaki, Koji Murono, Shigenobu Emoto, Yuichiro Yokoyama, Yuzo Nagai, Takahide Shinagawa, Yuichi Tachikawa, Satoshi Okada, Tetsuo Ushiku, and Soichiro Ishihara have no conflicts of interest to disclose.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eFunding\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eNo funding was received for conducting this study.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eEthics approval\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eThe present study was approved by the Ethics Committees of the University of Tokyo (No. 3252- [17]). This study was performed in line with the principles of the 1964 Declaration of Helsinki and its later amendments.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eConsent to participate\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eInformed consent was obtained from all individual participants included in the study.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eSiddharthan RV, Byrne RM, Dewey E, Martindale RG, Gilbert EW, Tsikitis VL (2019) Appendiceal cancer masked as inflammatory appendicitis in the elderly, not an uncommon presentation (Surveillance Epidemiology and End Results (SEER)-Medicare Analysis. J Surg Oncol 120:736\u0026ndash;739\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWang D, Ge H, Lu Y, Gong X (2023) Incidence trends and survival analysis of appendiceal tumors in the United States: Primarily changes in appendiceal neuroendocrine tumors. PLoS ONE 18:e0294153\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCarr NJ, Cecil TD, Mohamed F, Sobin LH, Sugarbaker PH, Gonz\u0026aacute;lez-Moreno S, Taflampas P, Chapman S, Moran BJ, Peritoneal Surface Oncology Group International (2016) A Consensus for Classification and Pathologic Reporting of Pseudomyxoma Peritonei and Associated Appendiceal Neoplasia: The Results of the Peritoneal Surface Oncology Group International (PSOGI) Modified Delphi Process. Am J Surg Pathol 40:14\u0026ndash;26\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMarmor S, Portschy PR, Tuttle TM, Virnig BA (2015) The rise in appendiceal cancer incidence: 2000\u0026ndash;2009. J Gastrointest Surg 19:743\u0026ndash;750\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eShaib WL, Goodman M, Chen Z, Kim S, Brutcher E, Bekaii-Saab T, El-Rayes BF (2017) Incidence and Survival of Appendiceal Mucinous Neoplasms: A SEER Analysis. Am J Clin Oncol 40:569\u0026ndash;573\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003evan den Heuvel MG, Lemmens VE, Verhoeven RH, de Hingh IH (2013) The incidence of mucinous appendiceal malignancies: a population-based study. Int J Colorectal Dis 28:1307\u0026ndash;1310\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCarr NJ, Bibeau F, Bradley RF, Dartigues P, Feakins RM, Geisinger KR, Gui X, Isaac S, Milione M, Misdraji J, Pai RK, Rodriguez-Justo M, Sobin LH, van Velthuysen MF, Yantiss RK (2017) The histopathological classification, diagnosis and differential diagnosis of mucinous appendiceal neoplasms, appendiceal adenocarcinomas and pseudomyxoma peritonei. Histopathology 71:847\u0026ndash;858\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRonnett BM, Zahn CM, Kurman RJ, Kass ME, Sugarbaker PH, Shmookler BM Disseminated peritoneal adenomucinosis and peritoneal mucinous carcinomatosis (1995) A clinicopathologic analysis of 109 cases with emphasis on distinguishing pathologic features, site of origin, prognosis, and relationship to pseudomyxoma peritonei. Am J Surg Pathol 19:1390\u0026ndash;1408\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eThe Chicago Consensus on peritoneal surface malignancies (2020) Management of appendiceal neoplasms. Cancer 126:2525\u0026ndash;2533\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eArnason T, Kamionek M, Yang M, Yantiss RK, Misdraji J (2015) Significance of proximal margin involvement in low-grade appendiceal mucinous neoplasms. Arch Pathol Lab Med 139:518\u0026ndash;521\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDindo D, Demartines N, Clavien PA (2004) Classification of surgical complications: a new proposal with evaluation in a cohort of 6336 patients and results of a survey. Ann Surg 240:205\u0026ndash;213\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYao MQ, Jiang YP, Wang YY, Mou YP, Fan JX (2024) Asymptomatic low-grade appendiceal mucinous neoplasm: A case report. World J Clin Cases 12:361\u0026ndash;366\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJelev G, Vassilev I, Usheva S, Yanev T, Sedloev T (2023) А case of a mucocele of the appendix - A diagnostic and therapeutic dilemma. Int J Surg Case Rep 105:108082\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKaneko M, Kawai K, Nozawa H, Hata K, Tanaka T, Nishikawa T, Shuno Y, Sasaki K, Emoto S, Murono K, Ishii H, Sonoda H, Watadani T, Takao H, Abe O, Ishihara S (2020) Utility of computed tomography and (18) F-fluorodeoxyglucose with positron emission tomography/computed tomography for distinguishing appendiceal mucocele caused by mucinous adenocarcinoma from other pathologies. Colorectal Dis 22:1984\u0026ndash;1990\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eIstl AC, Gage MM, Esquivel J, Ahuja N, Greer JB, Johnston FM (2021) Management of Low-Grade Appendiceal Mucinous Neoplasms (LAMN): An International Survey of Surgeons Performing CRS and HIPEC. Ann Surg Oncol 28:3831\u0026ndash;3837\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eArnold CA, Graham RP, Jain D, Kakar S, Lam-Himlin DM, Naini BV, Wu TT, Yeh MM, Torbenson MS (2019) Knowledge gaps in the appendix: a multi-institutional study from seven academic centers. Mod Pathol 32:988\u0026ndash;996\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eValasek MA, Thung I, Gollapalle E, Hodkoff AA, Kelly KJ, Baumgartner JM, Vavinskaya V, Lin GY, Tipps AP, Hosseini MV, LowyAM (2017) Overinterpretation is common in pathological diagnosis of appendix cancer during patient referral for oncologic care. PLoS ONE 12:e0179216\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eXiao J, Li P, Liu W (2021) Analysis of Clinical Characteristics of Low-Grade Appendiceal Mucinous Neoplasm (LAMN): A Retrospective Cohort Study of 51 LAMN Patients. J Invest Surg 34:721\u0026ndash;727\u003c/span\u003e\u003c/li\u003e\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":"appendiceal tumour, low-grade appendiceal mucinous neoplasm, laparoscopic surgery, partial cecum resection, surgical outcome","lastPublishedDoi":"10.21203/rs.3.rs-6903380/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6903380/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003ePurpose\u003c/h2\u003e \u003cp\u003ePreoperative pathological diagnosis of appendiceal tumors is difficult due to their anatomical nature. Although lymph node metastasis is rare in low-grade appendiceal mucinous neoplasms (LAMN), there is a risk of a positive surgical margin by appendectomy. Partial cecum resection is considered an option to obtain negative resection margins for LAMN; however, the benefits of this procedure via a laparoscopic approach remain unclear.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eWe retrospectively analyzed patients who underwent laparoscopy-assisted partial cecum resection (Lap-Ce) or ileocecum resection (Lap-ICR) for primary appendiceal tumors at our department. An intraoperative pathological diagnosis was requested at the surgeon\u0026rsquo;s discretion. Clinicopathological factors and surgical outcomes were compared among the two groups.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eIntraoperative pathological consultations were conducted for 86% (12 of 14 patients) of the Lap-Ce group and 4% (1 of 27 patients) of the Lap-ICR group. Fewer trocars (median: 3) were used in the Lap-Ce group than in the Lap-ICR group (5 trocars in all patients, p\u0026thinsp;\u0026lt;\u0026thinsp;0.0001). The Lap-Ce group had a shorter operative time (median: 113 vs. 197 min, p\u0026thinsp;\u0026lt;\u0026thinsp;0.0001), less blood loss (median: 1 vs. 32 mL, p\u0026thinsp;\u0026lt;\u0026thinsp;0.0001), and a shorter time to the first bowel movement than the Lap-ICR group (2 vs. 3 days, p\u0026thinsp;=\u0026thinsp;0.049). There was no recurrence in either group.\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e \u003cp\u003eLap-Ce was less invasive than Lap-ICR as assessed by perioperative variables. Therefore, Lap-Ce is considered to be useful as a primary surgical procedure for clinically benign lesions.\u003c/p\u003e","manuscriptTitle":"Laparoscopy-assisted partial cecum resection vs. ileocecal resection for non-malignant appendiceal neoplasms","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-06-23 05:54:36","doi":"10.21203/rs.3.rs-6903380/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":"f7ad1dd7-15cc-4d84-bdc6-f5578d65a0c0","owner":[],"postedDate":"June 23rd, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-07-17T06:24:00+00:00","versionOfRecord":[],"versionCreatedAt":"2025-06-23 05:54:36","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-6903380","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6903380","identity":"rs-6903380","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}