A randomized controlled trial to compare short-term outcomes following infragastric and infracolic omentectomy at the time of primary debulking surgery for epithelial ovarian cancer with normal-appearing omentum.

BACKGROUND: Omentectomy is an important procedure in surgery for epithelial ovarian cancer, but the scope of omentectomy is not recommended in the guidelines. This study was performed to evaluate the benefits and risks of infragastric omentectomy in patients with epithelial ovarian cancer. METHODS: This trial is a single center prospective study. Primary epithelial ovarian cancer patients with normal-appearing omentum were randomly assigned to either the control or experimental group and underwent infracolic or infragastric omentectomy, respectively. The primary endpoint was progression-free survival. This trial is registered on Chinese clinical trial registry site (ChiCTR1800018771). RESULTS: A total of 106 patients meeting the inclusion criteria for ovarian cancer were included during the study period. Of these, 53 patients underwent infracolic omentectomy, whereas 53 patients received infragastric omentectomy. Multivariate analysis revealed that infragastric omentectomy could improve the detection rate of omental metastases (OR: 6.519, P = 0.005). Infragastric omentectomy improved progression-free survival significantly for those cases with higher than stage IIB disease (HR: 0.456, P = 0.041). Based on the short-term results, infragastric omentectomy did not cause more perioperative complications. CONCLUSIONS: Compared with infracolic omentectomy, infragrastric omentectomy may be a more appropriate surgical procedure for stage IIB-IIIC epithelial ovarian cancer patients with normal-appearing omentum.

Vagus nerve signal has an inhibitory influence on the development of peritoneal metastasis in murine gastric cancer.

The vagus nerve is the only pathway for transmitting parasympathetic signals between the brain and thoracoabdominal organs, thereby exhibiting anti-inflammatory functions through the cholinergic anti-inflammatory pathway. Despite often being resected during lymph node dissection in upper gastrointestinal cancer surgery, the impact of vagotomy on postoperative outcomes in gastric cancer patients remains unclear. Sub-diaphragmatic vagotomy was performed on C57BL/6 mice. Three weeks later, syngeneic murine gastric cancer cell line YTN16P was injected into the peritoneal cavity, and the number of peritoneal metastases (PM) on the mesentery and omentum compared with control mice. The phenotypes of immune cells in peritoneal lavage and omental milky spots one day after tumor inoculation were analyzed using flow cytometry and immunohistochemistry. Intraperitoneal transfer of 3 × 105 YTN16P significantly increased the number of metastatic nodules on the mesentery in the vagotomy group compared to the control group. The omental metastasis grade was also significantly higher in the vagotomy group. Phenotypic analysis of immune cells in peritoneal lavage did not reveal significant differences after vagotomy. However, vagotomized mice exhibited a notable increase in milky spot area, with a higher presence of cytokeratin(+) tumor cells, F4/80(+) macrophages, and CD3(+) T cells. Vagus nerve signaling appears to regulate the immune response dynamics within milky spots against disseminated tumor cells and inhibits the development of PM. Preserving the vagus nerve may offer advantages in advanced gastric cancer surgery to reduce peritoneal recurrence.

An Ex Vivo Model of Ovarian Cancer Peritoneal Metastasis Using Human Omentum.

Ovarian cancer is the deadliest gynecologic malignancy. The omentum plays a key role in providing a supportive microenvironment to metastatic ovarian cancer cells as well as immune modulatory signals that allow tumor tolerance. However, we have limited models that closely mimic the interaction between ovarian cancer cells and adipose-rich tissues. To further understand the cellular and molecular mechanisms by which the omentum provides a pro-tumoral microenvironment, we developed a unique 3D ex vivo model of cancer cell-omentum interaction. Using human omentum, we are able to grow ovarian cancer cells within this adipose-rich microenvironment and monitor the factors responsible for tumor growth and immune regulation. In addition to providing a platform for the study of this adipose-rich tumor microenvironment, the model provides an excellent platform for the development and evaluation of novel therapeutic approaches to target metastatic cancer cells in this niche. The proposed model is easy to generate, inexpensive, and applicable to translational investigations.

An Alternative and Up-To-Date Recommendation for a Proper Site for Parathyroid Transplantation: The Omentum.

OBJECTIVES: Various sites have been used for parathyroid allotransplant, such as injection into the forearm, sternocleidomastoid, or deltoid muscles. However, transplant efficiency in these regions varies according to the results reported in the literature and also obtained from our previous studies. Using the omentum "as a natural incubator" for composite tissue-derived cell transplants to increase transplant success is possible. MATERIALS AND METHODS: To examine the efficiency of transplant sites for parathyroid allotransplant, we compared clinical cases from the literature and our experience with 23 cases. The omental transplant process is performed under general anesthesia by laparoscopic intervention. The abdominal cavity is visualized with an endocamera from a 5-mm trocar. With the help of a flexible catheter from another 5-mm trocar, microencapsulated or naked parathyroid cells are deposited on the omentum in approximately 30 mL of isotonic saline. The trocar sites are then sutured, and the surgery is terminated. Recipients were followed for 6 months with examination of biochemical parameters (parathormone, calcium, and phosphorus levels), medication use, and clinical scoring. RESULTS: In the 23 patients who received parathyroid allotransplants over the omentum, 7 recipients did not exhibit any changes according to the scoring system criteria. However, on average, serum calcium and phosphorus levels remained within the healthy reference range. In addition, use of oral medications among patients decreased, indicating successful transplant survival. These results were consistent with a significant decrease in hypocalcemia symptoms among patients. CONCLUSIONS: In the 23 patients, the success rate was 69.5% for the first 6-month period after transplant. Recent developments and large cohorts are needed to demonstrate the higher efficacy of parathyroid allotransplant over the omentum.

Omental coating attenuates implant-induced foreign body reaction in rats.

The objective of this study is to clarify whether the omental coating can effectively attenuate foreign body reaction (FBR) induced by implanted materials. Male Sprague-Dawley rats were injected with polydextran particle slurry intraperitoneally to activate the omentum. 7 days later, polyether polyurethane sponge discs were implanted subcutaneously on each side of the rat's back as the foreign implants to induce FBR. The next day, omental transposition were performed. The disc on the left side of each rat's back was wrapped with omental flap (omental group); the disc on the right side was untreated (control group). All discs were removed 21 days after implantation and assessed by determining the components of the fibrovascular tissue (angiogenesis, inflammation, foreign body giant cells (FBGCs) aggregation and fibrogenesis). In implants in omental group, micro vessel density (MVD), Hemoglobin (Hb) content and VEGF levels (pro-angiogenic cytokine) were increased when compared with implants from control group. Inflammatory parameters (IL-1ß; macrophage accumulation-NAG activity; neutrophil accumulation- MPO levels) were decreased in implants after omental coating. Also, collagen deposition, fibrous capsule thickness, and FBGCs decreased in implants from omental group. However, intra-implant levels of TNF-α and TGF-ß1 were not different after omental coating. Our findings showed for the first time that the omental coating around the implants attenuate the adverse FBR, it may be critical in developing new strategies to control FBR and improve the function and performance of the implanted materials.

Omentum Extracellular Matrix-Silk Fibroin Hydroscaffold Promotes Wound Healing through Vascularization and Tissue Remodeling in the Diabetic Rat Model.

Nonhealing diabetic wounds are often associated with significant mortality and cause economic and clinical burdens to the healthcare system. Herein, a biomimetic hydroscaffold is developed using omentum tissue-derived decellularized-extracellular matrix (dECM) and silk fibroin (SF) proteins that associate the behavior of a collagenous fibrous scaffold and a hydrogel to reproduce all aspects of the provisional skin tissue matrix. The chemical cross-linker-free in situ gelation property of the two types of SF proteins from Bombyx mori and Antheraea assamensis ensures the adherence of dECM with surrounding tissue on the wound bed, circumventing further suturing. The physicochemical and mechanical properties of the composite hydroscaffold (SF-dECM) were thoroughly evaluated. The hydroscaffolds were found to support the growth and proliferation of human dermal fibroblasts and influence the angiogenic potential of endothelial cells under in vitro conditions. Furthermore, the healing efficacy of the composites was evaluated by generating full-thickness wounds on a streptozotocin-induced diabetic rat model. The presence of dECM components in the composite facilitated the rate of wound closure, granulation tissue formation, and re-epithelialization by providing intrinsic cues to advance the inflammatory stage and stimulating angiogenesis. Collectively, as an off-the-shelf wound dressing requiring only a single topical administration, the SF-dECM hydroscaffold is a promising, cost-effective dressing for the management of chronic diabetic wounds.

The Gastrohepatic Ligament Approach Using Multiple Traction Tapes in Laparoscopic Spleen-Preserving Distal Pancreatectomy with Preservation of Splenic Vessels (with Video).

BACKGROUND: The gastrohepatic ligament approach is a form of robot-assisted spleen-preserving distal pancreatectomy (SPDP).1,2 This approach does not require omentum transection, peri-splenic dissection, or stomach traction. METHODS: Considering the advantages of preserving collateral pathways around the spleen, the authors performed the gastrohepatic ligament approach in laparoscopic SPDP while preserving splenic vessels (LSPDP), with specific modifications for laparoscopic surgery. The following surgical technique was performed. First, the gastrohepatic ligament was divided extensively, and all subsequent procedures were performed through the gastrohepatic ligament route. The superior and inferior borders of the pancreas then were dissected to encircle the common hepatic and splenic arteries with vessel loops and to expose the superior mesenteric vein (SMV) and portal vein. After taping of the pancreas on the SMV, the pancreas was divided using a linear stapler. Next, the pancreas was dissected from proximal to distal with preservation of the splenic vessels. Re-taping and traction of the splenic vessels and pancreas could facilitate the dissection of the pancreas body, especially at the splenic hilum. The appropriate counter traction using traction tapes allowed efficient laparoscopic procedures. The LSPDP was performed for three patients, including one obese patient (body mass index, 36 kg/m2) and two patients with an anomalous left hepatic artery branching from the left gastric artery. RESULTS: The mean operation time was 186 min, and the intraoperative blood loss was 37 mL. CONCLUSION: The gastrohepatic ligament approach could be an option for performing LSPDP with the counter traction technique for low-grade malignant tumors.

Concurrent management of lymphedema and breast reconstruction with single-stage omental vascularized lymph node transfer and autologous breast reconstruction: A case series.

INTRODUCTION: The omentum has gained recent popularity in vascularized lymph node transfers (VLNT) as well as its novel use as a free flap for autologous breast reconstruction. The omentum has multiple unique advantages. It can be harvested laparoscopically or in an open fashion when utilized with abdominally-based free flaps. Additionally, it can be split into multiple flaps for simultaneous autologous breast reconstruction with VLNT or for multiple sites of VLNT. We present the safe and advantageous use of the omentum for VLNT with simultaneous autologous breast reconstruction in a series of patients. METHODS: From the years 2019-2022, patients who underwent breast reconstruction with deep inferior epigastric artery perforator (DIEP) or muscle sparing tram (MS-TRAM) flaps with concurrent omental VLNT through a mini-laparotomy or breast reconstruction with Omental Fat-Augmented Free Flap (O-FAFF) with concurrent laparoscopic harvesting of omental VLNT were studied. Patient demographics included age, gender, comorbidities, prior radiation or chemotherapy, body mass index, complications, hospital length of stay, and surgical outcomes. RESULTS: A total of seven patients underwent omental VLNT with breast reconstruction for a total of 12 breasts and eight limbs treated. Three of the patients underwent autologous breast reconstruction using omental free flap. The mean age was 52.3 (range 40-75) years and mean body mass index (BMI) was 29.3 (range 23-38) kg/m2 . The flap survival rate was 100%. All the patients had successful reduction of extremity circumference and improvement of symptoms. The range of follow-up was 5 to 19 months, with an average follow-up of 14.6 months. There was only one complication among our 7 patients: a patient with a BMI of 38 developed a post-surgical abdominal wound treated with local wound care. Otherwise, post-operative courses were uneventful, and no further complications were reported. CONCLUSION: We demonstrate here additional evidence to the growing body of literature of the versatility and safety of the omentum to be utilized as an independent tool for surgical treatment of lymphedema as well as its simultaneous use with autologous breast reconstruction.

The prophylactic omentectomy procedure in reducing the complication rate of continuous ambulatory peritoneal dialysis in pediatric: A systematic review and meta-analysis.

INTRODUCTION: The role of the omentectomy procedure on Continuous Ambulatory Peritoneal Dialysis (CAPD) catheter placement in pediatric patients has been differently evaluated in the literature, with some studies showing improvement while others showing no difference. Our study aims to define the advantages of omentectomy compared to a procedure without omentectomy. METHODS: The literature searching in online databases (PubMed/MEDLINE, Cochrane Library, EMBASE, Scopus, and ClinicalTrial.gov) following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines, has been registered on PROSPERO (CRD42023412846). The protocol was performed through April 2023 and focused on pediatric patients treated with an omentectomy procedure and related complications. The risk of bias in each study was assessed using the risk of bias for the non-randomized control trials (ROBINS-I). The effect estimates were extracted as risk ratios with 95% confidence intervals (CI). The heterogeneity of the studies was considered as high heterogeneity if I2 values above 50% or p < 0.05. RESULTS: In the total of 676 articles identified in the database searching for screening, nine studies with 775 patients met the criteria for inclusion. The omentectomy procedure significantly showed a lower incidence of catheter obstruction compared to the control group, (OR 0.24 [95% CI, 0.12-0.49], p < 0.0001, I2 = 0%). Moreover, omentectomy demonstrated a similar trend in the rate of removal or reinsertion of the catheter with high heterogeneity, OR 0.25 [95% CI, 0.12-0.51), p = 0.0002, I2 = 70%). CONCLUSIONS: The omentectomy procedure showed a lower incidence of catheter obstruction and complications leading to removal or reinsertion of the catheter.

Comparative study of the immediate postoperative pain for the classical versus laparoscopic types of surgery within the treatement of inguinal hernias.

BACKGROUND: The inguinal hernia is the protrusion of intra-abdominal contents through a defect of the abdominal wall. This content can be represented by omentum, most frequently intestine. Theoretically, any intraperitoneal organ can be located in the hernia sac.The inguinal hernia is distinguished by several features: it is the most common form of hernia, it can occur in any age category, the only treatment is the surgical treatment, in the absence of the treatment, severe complications can endanger the patient's life.The treatment of hernias consists either in the use of a classical ("open") surgical procedure or of a laparoscopic procedure. The objective of both procedures is to remove and treat the hernia sac and repair the defect that appeared in the posterior wall of the groin canal. OBJECTIVES: The purpose of this study is to compare the effectiveness of the two surgery types, considering the immediate postoperative pain. METHODS: This paper is a prospective study conducted between September 2019 and February 2020, including a number of 80 patients admitted in the Department of General Surgery I and II, Emergency Clinical County Hospital of Târgu Mureș. In the study were included patients with uncomplicated inguinal hernia for which a classical or laparoscopic procedure was performed. Patients with complicated inguinal hernia (strangulation, incarceration) and patients with associated comorbidities (neoplasms, autoimmune diseases, neurological disorders) were excluded. For the study group were taken into consideration: demographic data (age, gender), type of surgery and the pain assessment using the VAS scale. RESULTS: Following the study, it was statistically confirmed the prevalence of elderly patients to the detriment of young patients in both classical and laparoscopic study group. As we age, the pain sensitivity decreases, an aspect highlighted in the classical study group, the statistics showing the presence of less pain in elderly patients on the second postoperative day compared to young patients. Regarding the pain in both postoperative days, it was statistically proved that the pain tends to decrease in intensity on the second postoperative day compared to the first postoperative day. CONCLUSIONS: As seen from this paper, taking into consideration the pain aspect, the two surgeries are very similar. Regardless of the chosen type of procedure, a preponderance of elderly patients was observed. The "Open Tension Free" procedure is a modern and efficient technique due to the absence of the local tension that can generate recurrence. The laparoscopic procedure has the advantage of reducing surgical trauma and minimizing recurrences. In the end, the type of treatment should be chosen by the surgeon after taking into consideration the type of hernia, the age and the patient's comorbidities and the economic considerations. KEY WORDS: Classical procedure, Inguinal hernia, Laparoscopic procedure.

Neuroendocrine tumour of the lesser omentum.

A man in his early 20s presented to us in the outpatient department with a history of diarrhoea for 4 months. Investigations revealed elevated serum chromogranin levels and an intensely avid lesion in the gastrohepatic ligament in Gallium DOTATATE positron emission tomography (PET). The tumour was excised laparoscopically, and no other lesions were seen. The patient improved clinically and had a normal serum chromogranin level postoperatively. He is currently much improved at the 1year follow-up. We did an extensive workup to look for a primary tumour. It was concluded that it was a de novo tumour arising from the lesser sac. The recommended investigations in case of neuroendocrine tumour (NET) with unknown primary include blood investigations to look for the functional status of the tumour, histopathological examination, including immunohistochemistry, and radiological imaging, which must include a Gallium DOTATATE PET. An isolated NET of the lesser sac has not been reported in the literature.

The significance of the omentum in locoregional immunotherapy for peritoneal carcinomatosis.

Our recent research has unveiled the potential of locoregional immunotherapy. Cytokine-armored viral vectors, such as modified vaccinia virus Ankara vector encoding single-chain interleukin-12 (MVA.scIL-12), can target the omentum and elicit a robust tumor-specific immune response, all the while minimizing toxicity.

Ruptured primary omental ectopic pregnancy during the first trimester.

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Omental infarction in an overweight child: conservative treatment is a safe approach.

A previously healthy but overweight (body mass index (BMI) of 24.4) adolescent boy presented with fever and significant right-sided abdominal pain. An abdominal ultrasound scan revealed an omental infarction (OI), which was treated conservatively. OI has been described in overweight teenage children with abdominal trauma but can be missed if not considered. A missed diagnosis could result in an unnecessary laparotomy or laparoscopic surgery. Although CT is the gold standard for diagnosis, ultrasonography is an effective approach to identifying OI in children. The benefits of early diagnosis of OI by abdominal ultrasound include a shorter hospital stay and a reduction in unnecessary investigations and surgery.

Intraperitoneal administration of a modified vaccinia virus Ankara confers single-chain interleukin-12 expression to the omentum and achieves immune-mediated efficacy against peritoneal carcinomatosis.

BACKGROUND: Peritoneal carcinomatosis is an advanced stage of cancer in which the disease has spread to the peritoneal cavity. In order to restore antitumor immunity subverted by tumor cells in this location, we evaluated intraperitoneal administrations of modified vaccinia virus Ankara (MVA) engineered to express single-chain interleukin 12 (scIL-12) to increase antitumor immune responses. METHODS: MVA encoding scIL-12 (MVA.scIL-12) was evaluated against peritoneal carcinomatosis models based on intraperitoneal engraftment of tumor cells. CD8-mediated immune responses, elucidated antitumor efficacy, and safety were evaluated following intravenous, intratumoral, or intraperitoneal administration of the viral vector. The immune response was measured by ELISpot (enzyme-linked immunosorbent spot), RNA sequencing, flow cytometry, intravital microscopy, and depletion of lymphocyte subsets with monoclonal antibodies. Safety was assessed by body-weight follow-up and blood testing. Tissue tropism on intravenous or intraperitoneal administration was assessed by bioluminescence analysis using a reporter MVA encoding luciferase. RESULTS: Intraperitoneal or locoregional administration, but not other routes of administration, resulted in a potent immune response characterized by increased levels of tumor-specific CD8+ T lymphocytes with the ability to produce both interferon-γ and tumor necrosis factor-α. The antitumor immune response was detectable not only in the peritoneal cavity but also systemically. As a result of intraperitoneal treatment, a single administration of MVA.scIL-12 encoding scIL-12 completely eradicated MC38 tumors implanted in the peritoneal cavity and also protected cured mice from subsequent subcutaneous rechallenges. Bioluminescence imaging using an MVA encoding luciferase revealed that intraperitoneal administration targets transgene to the omentum. The omentum is considered a key tissue in immune protection of the peritoneal cavity. The safety profile of intraperitoneal administration was also better than that following intravenous administration since no weight loss or hematological toxicity was observed when the vector was locally delivered into the peritoneal cavity. CONCLUSION: Intraperitoneal administration of MVA vectors encoding scIL-12 targets the omentum, which is the tissue where peritoneal carcinomatosis usually begins. MVA.scIL-12 induces a potent tumor-specific immune response that often leads to the eradication of experimental tumors disseminated to the peritoneal cavity.

A Novel Perivesical Fat Rotational Flap as an Alternative to Omental Interposition in Challenging Urological Reconstruction.

OBJECTIVE: To introduce the application of the perivesical fat rotational flap as a substitute for omental interposition during several complex urologic reconstruction. We highlight our technique using a case of salvage prostatectomy after initial high-intensity focused ultrasound for recurrent high-risk prostate cancer requiring future adjuvant radiation treatment. We have also successfully used this technique in the management of recurrent vesicovaginal, colovesical, rectourethral fistulas, and postradiation salvage prostatectomy setting. MATERIALS AND METHODS: Our first patient underwent salvage radical prostatectomy after developing high-risk localized prostate cancer after initial high-intensity focused ultrasound. The prostate was radically resected after stepwise posterior and anterior dissections. A flap of perivesical fat with a wide-based pedicle overlying the bladder dome was developed until it was rotated, positioned, and tethered overlying the anterior rectal wall in a tension-free manner. This perivesical fat interposition may have protected a radiated anterior rectal wall from future complications. In the second case, a recurrent vesicovaginal fistula that persisted for 2years postabdominal hysterectomy was repaired using the robotic approach. After fistula excision, layer closure, and perivesical flap interposition, successful repair was achieved. The third patient, who had a history of colon cancer managed with partial colectomy and radiation, developed a recurrent colovesical fistula, which was successfully repaired. Postrepair, a perivesical flap was developed and secured over the site. RESULTS: In the immediate postoperative follow-up period, there were no surgical complications. Long-term follow-up ranges from 1month to 3years without evidence of complication. CONCLUSION: In cases where omentum interposition is not feasible, our novel technique of a perivesical fat flap is a successful alternative for complex reconstruction.

General Morphological Characteristics of the Results of Experimental Modeling of Aseptic Peritonitis.

BACKGROUND: Aseptic peritonitis is a reaction of the local immune system aimed at rejection of a foreign body, which, having antigenic properties, does not (unlike a pathogen) counteract the immune system. The suture materials, namely catgut thread, used in intracavitary surgical operations possess xenogenic properties and can be used for antigenic stimulation of the immune system of the peritoneal cavity. Consequently, we decided to use a catgut suture for antigenic stimulation of the immune system of the peritoneal cavity and to study the morphological features of the results of experimental modeling of aseptic peritonitis in albino rats. METHOD: The study involved 15 Wistar albino male rats, weighing 286,13 ± 6,26 g. To study the dynamics of destructive changes made by the catgut implant in the peritoneal cavity of the experimental animals, the animals were assigned into three groups in accordance with the time interval of their euthanasia at 3, 7, and 14 days of the experiment. RESULTS: After modeling an aseptic peritonitis, the investigation the abdominal cavity showed that in four out of five animals of the first group, that is, on day 3 of the experiment, the catgut implant had adhered to the greater omentum. The search for the fifth implant led to an unexpected discovery: we found it conjoined with the second derivative of the visceral peritoneum, similar in structure to the greater omentum, but related to the testes. On day 7, the implant embedded into the peritoneal cavity of the animals, had adhered to the serous formations of the testes in all five cases (100%, three of them - to the left epididymal omentum, and another two - to the right one). On day 14 (n = 5) it was found that in three cases it had adhered to the serous formations of the testes (60%, one of them to the left epididymal omentum, another two - to the right one) and in two cases it had adhered to the greater omentum (40%). CONCLUSION: During the experiment on implantation of a xenogenic substrate in the form of flat bundles made from the catgut thread into the peritoneal cavity of sexually mature male rats, it was found for the first time that their acceptors were not only the greater omentum, but also two derivatives of the peritoneum, homeomorphic to it and associated with the epididymides, which we reasonably called epididymal omenta and described in details.

Mesorectal reconstruction with pedicled greater omental transplantation to relieve low anterior resection syndrome following total intersphincteric resection in patients with ultra-low rectal cancer.

BACKGROUND: Total intersphincteric resection (ISR) is the ultimate anus-preserving surgery for patients with ultra-low rectal cancer (ULRC), which can result in various degrees of anorectal dysfunction. Known as low anterior resection syndrome (LARS), it seriously affects the postoperative quality of life of patients. The aim of this study was to discuss the value of mesorectal reconstruction with pedicled greater omental transplantation (PGOT) to relieve LARS following total ISR in patients with ULRC, hoping to provide new ideas and strategies for the prevention and improvement of LARS. METHODS: We retrospectively analyzed hospitalization data and postoperative anorectal function of 26 ULRC patients, who were met inclusion and exclusion criteria in our center from January 2015 to February 2022. And combined with the results of anorectal manometry and rectal magnetic resonance imaging (MRI) defecography of some patients, we assessed comprehensively anorectal physiological and morphological changes of the patients after surgery, and their correlation with LARS. RESULTS: In this study, 26 patients with ULRC were enrolled and divided into observation group (n = 15) and control group (n = 11) according to whether PGOT was performed. There were no significant differences in surgical results such as operative time, intraoperative blood loss and postoperative complications between the two groups (P > 0.05). Postoperative follow-up showed that patients in both groups showed severe LARS within 3 months after surgery, but from the 3rd month after surgery, LARS in both groups gradually began to decrease, especially in the observation group, which showed faster recovery and better recovery, with statistically significant difference (P < 0.001). Through anorectal manometry, the mean rectal resting pressure in the observation group was significantly lower than that in the control group (P = 0.010). In addition, the postoperative thickness of the posterior rectal mesenterium in the observation group was significantly higher than that in the control group (P = 0.001), and also higher than the preoperative level (P = 0.018). Moreover, rectal MRI defecography showed that the neo-rectum had good compliance under the matting of greater omentum, and its intestinal peristalsis was coordinated. CONCLUSIONS: ULRC patients, with the help of greater omentum, coordinated their neo-rectum peristalsis after total ISR and recovery of LARS was faster and better. PGOT is expected to be an effective strategy for LARS prevention and treatment of ULRC patients after surgery and is worthy of clinical promotion.