Comparison of postoperative pain rates with different hysterectomy techniques: A retrospective study

Hysterectomy is the most frequent type of non-obstetric surgery in women. In the USA, more than 500,000 patients undergo hysterectomy annually. [ 1 ] Indications for hysterectomy were divided into “malignant diseases” and “benign diseases.” Pelvic inflammatory disease, abnormal uterine bleeding, endometrial hyperplasia, endometriosis, pelvic organ prolapse, uterine myoma, chronic pelvic pain, and obstetric-related conditions are among the benign indications for hysterectomy. Endometrial cancer, cervical intraepithelial neoplasia, invasive cervical cancer, ovarian cancer, and gestational trophoblastic tumors are among the most common causes of hysterectomy. [ 2 ] Total abdominal hysterectomy (TAH), laparoscopic hysterectomy (LH), transvaginal natural orifice transluminal endoscopic surgery (vNOTES), and vaginal hysterectomy (VH) are the most popular techniques. Intra-abdominal adhesions, patient body mass index (BMI), surgeon experience, and patient expectations are factors that determine the procedure style. [ 2 ] Postsurgical chronic pain (PSCP) is defined as pain persisting more than 3 months after surgery. [ 3 ] Some types of surgeries have a higher incidence of PSCP up to 50 to 60%, such as amputation, mastectomy, or major thoracic surgeries; however, simple surgeries may also cause PSCP. [ 4 , 5 ] PSCP after hysterectomy is an important issue involving diminished quality of life, recurrent physician attendance, and loss of labor. PSCP following hysterectomy has been reported at rates between 5 to 50% in the literature. [ 6 , 7 ] Previous studies identified that young age, preexisting pain before surgery, anxiety, depression, and poor social support are patient-related risk factors for PSCP. [ 8 ] Surgery-related risk factors include the extent and duration of the procedure, intraoperative nerve damage, and severity of postoperative pain. [ 9 – 11 ] Some studies have assessed the relationship between the surgical technique used for hysterectomy and the development of PSCP. In the literature, several reports exist regarding the incidence of PSCP corresponding to the hysterectomy technique. PSCP in patients who had undergone LH was declared between 20 and 31%, whereas it was between 12 and 18% for VH. [ 6 , 12 – 14 ] Pinto et al showed that AH has higher PSCP rates than LH and VH. [ 7 ] vNOTES is a new hysterectomy technique that has the advantages of VH and the ability of image magnification of endoscopic surgery. [ 15 ] Recent studies suggest that vNOTES is an effective and safe technique that provides better cosmetic results, shortens the duration of the surgery, and has no complications related to the port site compared to LH. [ 15 – 17 ] The primary aim of this retrospective study was to compare 4 different hysterectomy techniques (AH, LH, VH, and vNOTES) for CPSP. The secondary aim was to compare these 4 techniques regarding acute pain, analgesic requirements, complications, hospital stay, and intensive care unit requirements. Additionally, possible factors associated with CPSP were also evaluated. These were age, American Society of Anesthesiologists (ASA) risk score, presence of a psychological disorder, pain in the preoperative period, indication for surgery, volume of the resected hysterectomy material, additional bilateral salpingo-oophorectomy, blood transfusion requirement, perioperative complications, and hospital stay. Regarding our literature search, this is the first study to assess these 4 hysterectomy procedures in the same manuscript regarding the development of CPSP.

Conceptualization: Mustafa Kurçaloğlu, Mesut Önal, Cemal Yaşar. Data curation: Mesut Önal, Cemal Yaşar, Firdevs Yilmazlar, Pinar Uzun Uslu, Yasemin Yoleri. Formal analysis: Mustafa Kurçaloğlu. Methodology: Mustafa Kurçaloğlu, Mesut Önal, Yasemin Yoleri. Project administration: Mustafa Kurçaloğlu. Supervision: Mesut Önal. Writing – original draft: Mustafa Kurçaloğlu, Mesut Önal. Writing – review & editing: Mustafa Kurçaloğlu.

This retrospective study was conducted at Ondokuz Mayis University, Faculty of Medicine, Obstetrics and Gynecology Department, with the cooperation of the Algology (Pain Medicine) Department in accordance with the Declaration of Helsinki. Institutional ethics committee approval was obtained before conducting the study (decision number: OMUKAEK 2023/279). Informed consent was obtained from all the patients. Patients who underwent hysterectomy or hysterectomy and bilateral salpingo-oophorectomy due to nonmalignant causes between 1st of June 2019 and 31st of March 2023 were included in the study. The study data were collected from the hospital’s software database, nurse reports, anesthesiology records, and patient interviews. The records of patients with missing data, those operated due to malignant etiologies, and individuals reluctant to participate were not included in the study. Age, history of preoperative pelvic or abdominal pain, history of previous pelvic or abdominal surgery, preoperative analgesic use due to pelvic or abdominal pain, and presence of psychological disease were recorded. Patients with serious psychological problems were excluded from this study. The anesthesia risk scores mentioned in the anesthesia examination form according to the American Society of Anesthesiologists (ASA) classification were evaluated. [ 18 ] Patients with ASA status higher than III were not included in the study. Indications for hysterectomy were also evaluated. Surgical indications were divided into 7 groups: uterine myomas, adenomyosis, uterine prolapse, ovarian cysts, endometrial hyperplasia, mixed (more than 1) indications, and other indications. Volume of the resected hysterectomy material (VHM) (mL) (according to the specimen measurements applied by the Pathology Department), duration of surgery, perioperative complications, mean duration of discharge from hospital following the operation, intraoperative or postoperative blood transfusion requirement, and number of units of blood transfusion were noted. The Numerical Rating Scale (NRS) and the Turkish version of the Brief Pain Inventory Short Form (BPI-SF) were used as pain assessment tools. [ 19 – 21 ] Pain parameter records were assessed preoperatively and at 24 hours, 1 week, and 1, 3, and 6, months after the operation. Analgesics administered in postoperative were also noted. Non-steroidal anti-inflammatory drugs and paracetamol were categorized as “simple analgesics.” Patients requiring opioids were also noted. Based on the definition of the International Association of Studies of Pain, pain persisting for 3 months after the surgery was accepted as “PSCP.” [ 22 ] Patients were classified into 4 groups according to the type of surgery: abdominal hysterectomy (AH), LH, VH, and vaginal natural orifice transluminal endoscopic surgery (vNOTES). The Statistical Package for the Social Sciences version 22 (SPSS 22, IBM Software®, New York) was used for the statistical analysis of the study data. Nominal data were described using numbers and percentages, whereas ordinal data were described using means and standard deviations. The Kolmogorov–Smirnov test was used to determine the normal distribution of the parametric data sets. One-way ANOVA was used to compare parametric data with normal distribution patterns, and the Kruskal–Wallis test was used to compare non-parametric data between surgical technique groups. The chi-square test was used to compare nominal data between independent groups, and McNemar test was used to compare nominal data between dependent groups. Mann–Whitney U and Student t tests were used to compare the results of the 2 groups separately. Pearson test was used to determine the relationship between parametric data showing normal distribution, and Spearman test was applied to determine the relationship between data not showing normal distribution. Post hoc analysis was performed using Dunnett test. P values smaller than .05 were regarded as “statistically significant.”

A total of 312 patients underwent hysterectomy for nonmalignant indications during the study period. Individuals with insufficient records regarding the study data were excluded, and 264 patients were eligible for the study. Sixty-five (24.6%) underwent AH, 71 (26.9%) LH, 78 (29.5%) VH, and 50 (18.9%) vNOTES. All LH surgeries were multi-port interventions. There was no single-site LH in this study. “Transverse low abdominal incision” was performed in all patients of the AH group. The mean age was 52.22 ± 9.74 years. The mean ages of the AH, LH, VH, and vNOTES cases were 48.4 ± 8.08, 48.9 ± 6.46, 58.3 ± 11.0, and 52.2 ± 9.74 years, respectively. The VH group consisted of older patients than the other groups ( P  < .01). Age was not a risk factor for PSCP. The mean age of patients who experienced PSCP was 51.12 ± 9.45 years, while it was 52.36 ± 9.79 in patients without PSCP ( P  = .51). Correlation analysis also did not show age as a risk factor for high NRS 3 months after the operation ( P  = .48). Regarding ASA risk classification, 104 (39.4%) were ASA I, 140 (53.0%) were ASA II, and 20 (7.6%) were ASA III. There was no significant difference between the groups in terms of ASA risk scores ( P  = .11). ASA score was not found to be a risk factor for PSCP development ( P  = .34). Eighty-nine (33.7%) patients underwent hysterectomy for uterine myomas, 13 (4.9%) had adenomyosis, 60 (22.7%) had uterine prolapse, 37 (14.7%) had ovarian cyst, 51 (18.9%) had endometrial hyperplasia, 3 (1.1%) had a mixed diagnosis, and 11 (4.1%) had other reasons. There was no difference in the frequency of postoperative pain between the indications for surgery ( P  = .20). There were some significant differences between the study groups in terms of previous abdominal surgery. While 39 (60%) patients in the AH group had a history of abdominal surgery, 42 (59.2%) had LH, 28 (25.9%) had VH, and 22 (44.0%) had a history of abdominal surgery. When the groups were compared separately, it was observed that only the difference between AH and VH was statistically significant ( P  < .001). No correlation was found between previous abdominal surgery and the PSCP frequency ( P  = .30). The mean VHM of the groups is presented in Table 1 . It was found that the average size of the hysterectomy material resected in AH was significantly larger than that in the other groups ( P  < .001). There was no correlation between VHM and PSCP ( P  = .82). Average volumes of the resected hysterectomy materials and mean duration of the surgeries. AH = abdominal hysterectomy, LH = laparoscopic hysterectomy, VH = vaginal hysterectomy, vNOTES = transvaginal natural orifice transluminal endoscopic surgery. In post hoc analysis, it was observed that the volume of the hysterectomy material was significantly higher in group AH than in other groups. In post hoc analysis, it was observed that the duration of the surgery was significantly lower in group AH than LH and vNOTES, but not than VH. In Table 1 , The mean duration of surgery is presented. The mean operative duration was shorter in the AH group than in the other groups. It was statistically significant compared to LH and vNOTES ( P  < .01 both) but not significant compared to VH ( P  = .40). Blood transfusion rates were significantly higher in the AH group than in the other groups (all P  < .001). While 16 (24.6%) patients with AH required blood transfusion in the perioperative period, this number was 5 (7.0%), 3 (3.8%), and 1 (2%) required blood transfusion for LH, VH, and vNOTES, respectively. We should note that there were no major bleeding complications during the surgery, and except for 2, all patients received blood transfusions in semi-elective conditions 1 or 2 days after surgery due to slow oozing. PSCP rates were not statistically significant in patients who received blood transfusion (5 of 25 [20%]) and without transfusion (24 of 239 [10.0%]) ( P  = .13). The NRS and BPI scores of the patients from the preoperative period to the 6th month are presented in Tables 2 and 3 . The frequency of patients with postoperative pain is shown in Table 4 and Figure 1 . There was no significant difference between groups regarding preoperative NRS and BPI scores (the P value was .25 for NRS and .31 for BPI-SF). Pain parameters, including NRS, BPI-SF, and pain frequency, were significantly higher in the AH group than in the other groups at the 24th hour and 1st-week evaluations. In the 1st-month data, the mean NRS and BPI-SF scores of the vNOTES group were lower than those of the other groups. This was statistically significant when comparing the NRS and BPI-SF scores of AH and NRS scores of VH, but it was not significant when comparing the LH and BPI scores of VH. Pain parameters were significantly lower in the vNOTES group than in the other groups at 3 and 6 months following after surgery. Thirty patients (11.3%) reported a PSCP. Three months after the procedure, 9 (3.4%) patients reported intense pain with an NRS scores of 6 or higher, and 8 patients (3.0%) reported intense pain in the 6th month. Mean NRS scores of patients. AH = abdominal hysterectomy, LH = laparoscopic hysterectomy, NRS = Numerical Rating Scale, VH = vaginal hysterectomy, vNOTES = transvaginal natural orifice transluminal endoscopic surgery. There is a significant difference between AH and VH. NRS is significantly higher in AH than LH and vNOTES. NRS is significantly higher in AH than vNOTES. NRS of vNOTES is significantly lower than other groups. Mean BPI-SF scores of the patients. AH = abdominal hysterectomy, BPI-SF = Brief Pain Inventory Short Form, LH = laparoscopic hysterectomy, VH = vaginal hysterectomy, vNOTES = transvaginal natural orifice transluminal endoscopic surgery. BPI-SF scores were significantly higher in AH than LH and VH. BPI-SF scores were significantly higher in AH than LH and vNOTES. Results of vNOTES were significantly lower than AH and VH, but not lower than LH. Frequency of patients with pain complaint. AH = abdominal hysterectomy, LH = laparoscopic hysterectomy, VH = vaginal hysterectomy, vNOTES = transvaginal natural orifice transluminal endoscopic surgery. AH is significantly higher than LH and vNOTES. vNOTES is significantly lower than other groups. Statistically significant. Percentage of patients reporting pain. When the mean duration of postoperative pain was assessed, it was found that vNOTES had a shorter duration of postoperative pain than the other groups. The mean duration of postoperative pain was 3.54 ± 9.90 days in vNOTES, 31.23 ± 62.22 days in AH, 19.98 ± 53.67 days in LH, and 24.71 ± 57.86 days in VH groups. Post hoc analysis showed that the differences between vNOTES and AH and vNOTES and VH were statistically significant ( P  < .01, P  = .01, respectively) but not between vNOTES and LH ( P  = .08). A positive moderate correlation was also observed between the duration of postoperative pain and NRS scores at the 3rd month ( P  < .01, correlation coefficient = 0.59). A notable finding of our study was the relationship between NRS scores at the 24th hour, at 1 week, and the development of PSCP. The mean 24th-hour NRS scores of patients without chronic postoperative pain was 1.91 ± 2.94, it was 4.88 ± 3.17 for patients who experienced chronic postoperative pain ( P  < .01). Additionally, the mean 24th-hour BPI-SF scores of patients without chronic postoperative pain was 9.0 ± 15.68, while it was 29.66 ± 22.52 in patients who experienced chronic postoperative pain ( P  < .01). The mean NRS score of patients without PSCP at 1 week was 0.83 ± 1.88, and for patients with PSCP was 4.65 ± 2.39 ( P  < .01). Furthermore, while only 7 patients experienced PSCP among 162 patients who did not report acute postoperative pain (0.4%), PSCP developed in 23 of 102 patients who reported acute postoperative pain at the 24th hour (22.5%) ( P  < .01, odds ratio = 5.2). Similarly, PSCP developed in 26 of 74 patients who reported pain in the 1st week and in only 4 of 190 patients who did not report pain in the 1st week ( P  < .01, odds ratio = 17.5). Mean hospital stays following surgery for AH, LH, VH, and vNOTES cases were 4.13 ± 1.59, 3.53 ± 1.74, 2.93 ± 3.28, and 2.46 ± 1.13 days, and this was significantly increased in the AH group ( P  < .01). There was no relationship between the duration of hospital stay and the PSCP ( P  = .52). A significant difference was observed in perioperative complication frequencies ( P  = .03). While there were no perioperative complications in the AH group, 6 cases (8.5%) had complications in the LH group, 9 (11.5%) in the VH group, and 2 (4%) in the vNOTES group. None of these complications were major or irreversible (Table 5 ). Perioperative complication frequencies. AH = abdominal hysterectomy, LH = laparoscopic hysterectomy, VH = vaginal hysterectomy, vNOTES = transvaginal natural orifice transluminal endoscopic surgery. Preoperative abdominal or pelvic pain complaints were risk factors for chronic pain development ( P  < .01). Seventy-five patients (28.4%) had pain complaints before surgery, and CPSP developed in 14 (18.6.0%) patients, while CPSP developed in 16 of 189 patients (8.4%) without pain in the preoperative period ( P  = .01). Thirty (11.3%) patients had previous psychiatric diagnoses, and no relationship was observed between psychiatric history and chronic postoperative pain ( P  = .79). The types and rates of analgesics are listed in Table 6 . No significant differences were observed between the groups before the surgery. At 24th-hour records, the number of patients requiring opioids was higher in the AH group. This was statistically significant with separate comparisons of LH and VH ( P  < .001 for both), but not significant compared to vNOTES ( P  = .09). No significant difference was found 1 week after surgery. In the 1st-month evaluations, the rate of patients using simple analgesics was lower in the vNOTES group. It was statistically significant compared to AH ( P  = .01) but not significant compared to LH ( P  = .22) and VH ( P  = .06). In the 3rd- and 6th-month data, it was found that none of the patients were using opioids, and the rate of simple analgesic usage was significantly lower in the vNOTES group than in the other groups. For the 3rd month, the P values for the AH and vNOTES comparisons were < .001, vNOTES and LH were .03, and vNOTES and VH were .01. In the 6th month, P values for vNOTES and AH comparison were < .001, vNOTES and LH were .03, and vNOTES and VH were < .001. Analgesic usage of patients. AH = abdominal hysterectomy, LH = laparoscopic hysterectomy, VH = vaginal hysterectomy, vNOTES = transvaginal natural orifice transluminal endoscopic surgery. AH was significantly lower than LH and VH, but not than vNOTES. AH was significantly higher than LH, but not than others. vNOTES is significantly lower than AH but not than others. vNOTES is significantly lower than others. Significant difference exists.

The results of this study showed that vNOTES is superior to other hysterectomy techniques in terms of shorter duration of postoperative pain and a decreased rate of PSCP development. When the frequency and intensity of pain are inspected in Tables 2 to 4, the superiority of vNOTES becomes obvious in the 1st month of assessment. None of the 50 patients who underwent vNOTES in this study reported pain complaints 3 months and 6 months after the surgical procedure. We suggest that the superiority of vNOTES is a result of its minimally invasive surgical approach. vNOTES has the benefits of both laparoscopic and vaginal surgery. Vaginal access is superior in terms of aesthetics because there is no scar on the abdominal incision. In addition, vNOTES is free of abdominal trocar complications (abdominal wall infection, abdominal pain, and facial herniation). In addition, adhesions due to previous abdominal surgeries affect vNOTES less because of the transvaginal approach to the procedure. [ 23 ] In this study, compared to other techniques, AH had a significantly higher frequency and severity of pain in the 1st month after surgery. Regarding the findings of previous studies have shown that AH is associated with a higher frequency of pain due to a large incision and increased nerve damage. [ 9 ] Nevertheless, we cannot underrate the clinical advantage of AH when we look at Table 1 and see the higher volumes of the evacuated material. After 1 month, the pain parameters in the AH, LH, and VH groups were similar. There are conflicting results regarding PSCP rates between the types of hysterectomy surgery. In some clinical studies, PSCP frequencies following AH have been reported as 25 to 26%. [ 9 , 12 , 24 ] The rates reported in the literature for chronic pain following VH were lower than AH (12–18%), but the rates of LH were similar to AH (20–31%). [ 6 , 9 , 13 ] On the other hand, some older studies have reported that PSCP frequencies of AH, LH, and VH are not very different. [ 25 – 28 ] We observed that the rate of patients with pain complaints was very similar between the AH and VH groups. All LH surgeries involved multi-port access in this study. In a 70-patient prospective cohort study, Kliethermes et al compared the postoperative pain scores (Visual Analog Scale [VAS]) between single-site and multi-port LH, and they found that the VAS scores of the single-site group were smaller than those of the multi-port group on postoperative day 21. However, these studies did not assess the chronic postoperative period. [ 29 ] The overall chronic pain frequency in this study (11.3%) was one of the lowest reported in the literature. If vNOTES was not considered, the rate would be 14.0%. In previous studies, PSCP after hysterectomy was reported to be between 5 and 32%, and even up to 50%. [ 7 , 14 , 28 ] However, these rates are influenced by the definition of CPSP and characteristics of the patient population. In this study, based on the chronic pain definition of International Association of Studies of Pain, PSCP was defined as pain persisting 3 months after the procedure. [ 22 ] Additionally, cancer patients were not included in our study to protect the homogeneity of the study population, which may have contributed to the relatively low rate of CPSP. The secondary aim of this study was to identify risk factors for the development of PSCP. In the literature, risk factors identified for chronic pain after hysterectomy include young age, pain epigenetics, preexisting pain before surgery, psychological factors such as anxiety, depression, stress, poor social support, intraoperative nerve damage, extent and duration of surgery, and the severity of postoperative pain. [ 9 – 11 ] Some of our findings were similar to the literature, while others were not. Preoperative pain and acute postoperative pain were the only parameters shown to be risk factors for PSCP in this study. Corresponding to the higher NRS and BPI-SF scores and higher rates of opioid demand at the 24th hour in the AH group, we suggest that this difference was a result of higher postoperative pain, larger abdominal incision, and increased surgical stress. When perioperative complications were evaluated, no irreversible or catastrophic events occurred in any of 264 patients (Table 5 ). Surprisingly, no intraoperative complications were reported in any of the 65 AH group patients. This finding may be a result of the higher surgical experience of our surgeons because they have decades of AH experience and are more familiar with this technique than with other hysterectomy approaches. Increased BMI is a risk factor for postoperative pain following hysterectomy. Unfortunately, we did not have sufficient data to analyze patients’ BMIs. Similarly, we did not have enough data to analyze the loss of blood volume during surgery because, except for 2, none of the patients had clinically important intraoperative bleeding, and the anesthesia staff did not record small amounts of estimated bleeding volumes. This study has some limitations, most of which originate from its retrospective design. First, the postoperative analgesic consumption could not be standardized. Therefore, we could only categorize analgesic usage into simple analgesics (paracetamol and non-steroidal anti-inflammatory drugs) and opioids. Unfortunately, only a very small percentage of patients used opioids during the assessment period. When the pain rates and analgesic usage in this study were inspected, it was clearly seen that none of the patients used any kind of opioid, despite 19 (7.2%) of the study population reporting intense pain (NRS 6 or higher). We also observed that opioids were almost never administered after patients were discharged from the hospital. It is possible that this is due to opiophobia among both physicians and patients. In the pain management field, opiophobia is an important problem in Eastern countries, while opiophilia is an issue in Western countries. [ 30 ] Wen et al reported that after hysterectomy, 1.38% of opioid-naïve women became chronic opioid consumers. [ 31 ] Another important limitation of our study was that we could not discriminate between the neuropathic and nociceptive pain patterns. To distinguish between neuropathic and nociceptive origin pain, assessment tools such as the Douleur Neuropathique 4 (DN-4), Leeds Assessment of Neuropathic Symptoms and Signs (LANSS) scale, and PainDETECT questionnaire are used. Previous studies using DN-4 as the assessment tool found that 17 to 52% of patients with CPSP after hysterectomy reported neuropathic pain. [ 9 , 12 , 14 , 28 ] Furthermore, our study did not have data regarding the exact pain location, such as pain on the scar tissue, unilateral, bilateral, or radiating elsewhere. Another major limitation is the inability to interfere with the surgical decisions. This was not a randomized controlled study, so the physicians made their choice of surgery type based on their own clinical experience and points of view. Nevertheless, considering the larger VHMs, surgeons preferred AH when they had a larger uterus for resection. As indicated above, vNOTES has several benefits over classical laparoscopic and open surgeries. These are less invasive, decreased morbidity, improved postoperative recovery, decreased postoperative pain intensity, decreased wound-site infection rates, lesser port-site herniation, and better aesthetic look. [ 32 ] The findings of this study demonstrated the superiority of vNOTES for postoperative pain. However, this finding does not mean that vNOTES is the best surgical approach for hysterectomy or that it should be performed in every patient. However, no other surgical techniques can be used. AH, LH, and VH are all effective and reliable surgeries that heal hundreds of thousands of women annually. Surgeons must always assess patients as unique individuals and consider the presence of intra-abdominal adhesions, BMI, surgical experience, and patient expectations. In conclusion, regarding the results of this study, we suggest that the vNOTES technique is superior to other hysterectomy techniques in terms of postoperative pain duration and chronic postsurgical pain frequency, without increased complication rates. Preoperative and acute postoperative pain are accompanying risk factors for the development of chronic postsurgical pain after hysterectomy.