This review provides an overview regarding the abdominal effects of an omentectomy, with or without extra-peritoneal reconstructions. In general, reported complication rates were low. Short-term complications involved ileus, bowel stenosis, abdominal abscess and sepsis (range 0.0%-23%). Donor-site hernia was mainly reported as long-term complication (up to 32%) and negligible gastrointestinal complications were observed. However, the level of evidence and methodological quality are quite low with a maximum of 8.5 years follow-up.

Surgical management of Borderline ovarian tumors (BOT) can range from unilateral cystectomy to a more extensive surgical staging. However, the role of hysterectomy within the surgical staging is still debated.
To assess the impact of hysterectomy on survival outcomes in BOT patients.
5 electronic databases were searched from their inception to April 2021 for all peer-reviewed, retrospective or prospective studies, which compared treatment including hysterectomy versus treatment not including hysterectomy for BOT, in terms of recurrence and/or death. Pooled odds ratios (OR) with 95% confidence interval for recurrence, death due to BOT and death of any cause were calculated comparing hysterectomy group versus no hysterectomy group. Subgroup analyses for recurrence were based on BOT histotype (mucinous and serous) and FIGO stage (I and II-III).
Twelve studies assessing 2223 patients were included. Compared to no hysterectomy group, hysterectomy group showed an OR of 0.23 (p = 0.00001) for recurrence, 1.26 (p = 0.77) for death due to BOT and 4.23 (p = 0.11) for death of any cause. At subgroup analyses, compared to no hysterectomy group, hysterectomy group showed an OR for recurrence of 0.21 (p = 0.003) in serous subgroup, of 0.46 (p = 0.18) in mucinous subgroup, of 0.23 (p = 0.0006) in FIGO stage I subgroup, and of 0.29 (p = 0.04) in FIGO stage II-III subgroup.
Uterine-sparing surgery might be recommended in all BOT patients since it seems to increase the risk of recurrence, but not those of death due to disease or death of any cause.

Carcinosarcoma, also known as malignant mixed Müllerian tumor (MMMT), includes both malignant epithelial and mesenchymal elements. While the endometrium is the most frequent known site for carcinosarcomas, their development in the fallopian tube is rare condition, only accounting for 0.1 to 0.5% among all gynecological malignancies. Fallopian tube MMMT is associated with an aggressive progression. A total of 94 previous case reports were reviewed and divided, after applying the exclusion criteria, into 2 groups: No evidence of disease (NED) Group including 33 patients reported to be without any residual disease at the end of the follow-up period; death of disease (DOD) Group including 51 patients who died due to the progression of fallopian carcinosarcoma or its complications. The gathered data were statistically analyzed together with a case from our clinical experience: a 65-year-old postmenopausal patient with a final histological diagnosis of fallopian carcinosarcoma staged FIGO IC2, synchronous with a serous endometrial intraepithelial carcinoma. Patient age between 41 and 60 years, symptoms at presentation and computed tomography (CT)/magnetic resonance imaging (MRI) tumor evidence are prognostic factors (P<0.05). Omentectomy [odds ratio (OR)=0.3545] and pelvic lymphadenectomy (OR=0.3732) were found to be significant factors for survival (P<0.05). Fimbrial localization of the tumor is a negative prognosis factor (OR=4.263), as well as the heterologous type of tumor (OR=2.880). Chemotherapy was found to improve survival (OR=0.2679) while radiotherapy had no influence on patient prognosis. Reporting these rare cases could be essential for obtaining more precise information regarding the treatment and prognosis of patients with MMMT of the fallopian tube, in order to improve patient survival and quality of life.

BACKGROUND: The omentum is an organ that is easily sacrificed during abdominal surgery. The scope of omentectomy and whether a routine omentectomy should be performed are still unknown.
OBJECTIVE: To review the literature in order to determine the physiological functions of the omentum and the roles it plays in pathological events in order to reveal the necessity for removal and preservation of the omentum.
METHODS: A clinical review of the English language literature based on the MEDLINE (PubMed) database was conducted using the keywords: \"abdomen\", \"gastrointestinal\", \"tumor\", \"inflammation\", \"omental flap\", \"metastasis\", \"omentum\", and \"omentectomy\". In addition, reports were also identified by systematically reviewing all references in retrieved papers.
RESULTS: The omentum functions as a natural barrier in areas where pathological processes occur in the abdominal cavity. The omentum limits and controls inflammatory and infectious pathologies that occur in the abdomen. It also aids in treatment due to its cellular functions including lymphatic drainage and phagocytosis. It shows similar behavior in tumors, but it cannot cope with increasing tumor burden. The stage of the disease changes due to the tumor mass it tries to control. Therefore, it is considered an indicator of poor prognosis. Due to this feature, the omentum is one of the first organs to be sacrificed during surgical procedures. However, there are many unknowns regarding the role and efficacy of the omentum in cancer.
CONCLUSIONS: The omentum is a unique organ that limits and controls inflammatory processes, foreign masses, and lesions that develop in the abdominal cavity. Omental flaps can be used in all anatomical areas, including the thorax, abdomen, pelvis, and extremities. The omentum is an organ that deserves the title of the abdominal policeman. It is generally accepted that the omentum should be removed in cases where there is tumor invasion. However, the positive or negative contribution of omental resection in the treatment of abdominal pathologies should be questioned.

BACKGROUND: Omentectomy has been traditionally a part of standard radical gastrectomy. Its clinical benefit for locally advanced gastric cancer (LAGC) remains controversial. This study aimed at evaluating the impact of gastrectomy with omentum preservation (GOP) on survival, recurrence, surgical outcomes and postoperative complications by comparing with gastrectomy with omentum resection (GOR).
METHODS: Original studies comparing GOP with GOR in LAGC were searched. Meta-analysis was performed using RevMan 5.4.
RESULTS: Seven studies involving 1879 patients were analyzed. Compared with GOR, GOP achieved significantly better overall survival (HR = 0.75 [0.60, 0.95], P = 0.01), with similar relapse-free survival (HR = 0.84 [0.68, 1.03], P = 0.10). The two groups had similar total recurrence rate (OR = 0.86 [0.68, 1.08], P = 0.19) and no significant differences in rates of peritoneal, hematogenous, locoregional or distant lymph node recurrences. GOP had significantly less blood loss (MD = -83 [-139, -28] ml, P = 0.003) and tended to have shorter operation time (MD = -28 [-58, 2] min, P = 0.06), with similar harvested number of lymph nodes (MD = -0.4 [-2.6, 1.8], P = 0.70). The incidences of total all grade and major complications were similar in GOP and GOR (all grade: 31.8% vs. 30.3%, OR = 1.08 [0.79, 1.46], P = 0.64; major: 9.2% vs. 10.1%, OR = 1.14 [0.55, 2.34], P = 0.73). There were no significant differences in incidences of complication or postoperative mortality.
CONCLUSIONS: Omentum preservation did not affect curability or survival in LAGC. These findings require validation in randomized controlled trials with large sample sizes.

UNASSIGNED: Complete omentectomy is considered to be essential in the radical gastrectomy for gastric cancer (GC), but its clinical benefit remains unclear. This study aims to evaluate the efficacy of omentum-preserving gastrectomy (OPG) for patients with GC.
UNASSIGNED: Studies comparing the surgical and oncological outcomes of OPG and gastrectomy with complete omentectomy (GCO) for GC up to March 2021 were systematically searched from PubMed, Web of Science, Embase, and Cochrane Library. A pooled analysis was performed for the available data regarding the baseline features, surgical and oncological outcomes. The RevMan 5.3 software was used to perform the statistical analysis. Quality evaluation and publication bias were also conducted.
UNASSIGNED: Nine studies with a total of 3335 patients (1372 in the OPG group and 1963 in the GCO group) undergoing gastrectomy were included. In the pooled analysis, the baseline data in two groups were all comparable (p > 0.05). However, the OPG group was associated with shorter operative time (MD = -18.67, 95% CI = -31.42 to -5.91, P = 0.004) and less intraoperative blood loss (MD = -38.09, 95% CI = -53.78 to -22.41, P < 0.00001) than the GCO group. However, the number of dissected lymph nodes (MD = 2.16, 95% CI = -0.61 to 4.93, P = 0.13), postoperative complications (OR = 0.92, 95% CI = 0.74 to 1.15, p = 0.47), overall recurrence rate (OR = 0.83, 95% CI = 0.66 to 1.06, p = 0.14), peritoneal recurrence rate (OR = 0.91, 95% CI = 0.65 to 1.29, p = 0.60), 3-year relapse-free survival (RFS) rate (OR = 1.40, 95% CI = 0.86 to 2.27, p = 0.18), and 5-year RFS rate (OR = 1.21, 95% CI = 0.95 to 1.55, p = 0.12) of the two groups were comparable.
UNASSIGNED: OPG might be an oncologically safe procedure with better surgical outcomes for patients with GC than GCO. However, high-quality randomized controlled trials are needed to confirm this benefit.

BACKGROUND: We performed a meta-analysis to investigate the efficacy of complete omentectomy (CO) in patients undergoing radical gastrectomy for gastric cancer.
METHODS: We conducted a literature search in PubMed, Web of Science, and the Cochrane Library databases for clinical research that compared CO with non-complete omentectomy (NCO). These articles were published prior to April 2021. Overall survival (OS) rates, relapse-free survival (RFS) rates, recurrence rates, operation times, estimates of blood loss, numbers of harvested lymph nodes, complications, and lengths of hospital stays were compared using relative risks (RRs) and weighted mean differences (WMDs). RevMan 5.3 software was used for statistical analysis.
RESULTS: Nine studies that included 3329 patients (1960 in the CO group) and 1369 in the NCO group comprised the analysis. The meta-analysis showed that CO was associated with a decreased 3-year OS rate (RR = 0.94, 95% CI 0.90-0.98, P = 0.005) and 5-year OS rate (RR = 0.93, 95% CI 0.88-0.98, P = 0.007). However, it was not associated with the 3-year RFS rate (RR = 0.97, 95% CI 0.90-1.04, P = 0.44), 5-year RFS (RR = 0.98, 95% CI 0.90-1.06, P = 0.60), or recurrence rate (RR = 1.17, 95% CI 0.95-1.45, P = 0.15) compared to the NCO group. For surgical-related outcomes, significant heterogeneity existed between the studies. Compared to the NCO group, CO was found to be associated with significantly more estimated blood loss (WMD = 250.90, 95% CI 105.90-396.28, P = 0.0007) and less harvested lymph nodes (WMD = - 3.59, 95% CI - 6.88, - 0.29, P = 0.03). Although, there was no significant difference in the surgical time (WMD = 15.93, 95% CI - 0.21, 32.07, P = 0.05). No statistically significant differences were observed in the rates of overall (P = 0.79) and major complications (P = 0.90), or the lengths of hospital stays (P = 0.11) between the two groups.
CONCLUSIONS: Based on the available evidence, CO is not superior to NCO in terms of survival. CO is not recommended as a routine surgery for gastric cancer. Future well-designed high-quality RCTs are warranted.

Omental bleeding is potentially life-threatening. There are many causes of omental bleeding including trauma, neoplasia, arterial aneurysm rupture, omental torsion, vasculitis, or segmental arterial mediolysis (SAM). Without remarkable pathological features, the diagnosis of idiopathic omental bleeding is made. Omental bleeding is relatively a rare disease, and there is no established treatment strategy.  A 53-year-old woman was brought to the ED for sudden onset abdominal pain. CT revealed hematoma in the omentum and was diagnosed as idiopathic omental bleeding accordingly. The patient underwent laparoscopic partial omentectomy and was discharged nine days after surgery. The pathological findings of the resected omentum were not remarkable, and the final diagnosis was made as idiopathic omental bleeding. In some case reports of omental bleeding, interventional radiology (IVR) was chosen for hemostasis, but IVR cannot resect tissue of omentum so it is difficult to make a pathological diagnosis. The surgical approach of idiopathic omental bleeding is uncommon. However, the use of the laparoscopic approach hasn\'t been reported in the literature. Laparoscopic partial omentectomy can provide effective hemostasis. We report laparoscopic partial omentectomy surgical procedure and review of the literature.

To explore the influence of omentectomy on postoperative outcomes in patients with locally advanced gastric cancer (LAGC).
Although several meta-analyses have investigated the influence of bursectomy on postoperative outcomes in patients with LAGC, no meta-analyses have explored the influence of omentectomy on postoperative outcomes in such patients.
We performed a comprehensive electronic search of the literature up to December 2020 to identify studies that compared postoperative outcomes between patients with LAGC who did and did not undergo omentectomy. A meta-analysis was performed using random-effects models to calculate the risk ratio (RR) and 95% confidence interval (CI), and heterogeneity was analyzed using I2 statistics.
Eight retrospective studies involving a total of 2658 patients with LAGC who underwent surgery were included in this meta-analysis. Among them, 3 propensity score matching (PSM) studies demonstrated that the 5-y recurrence-free survival (RFS) rate was 72.9% (314/431) in patients with LAGC who did not undergo omentectomy, whereas it was 70.3% (303/431) in those who did. The results revealed no significant difference in 5-y RFS between groups (RR, 0.91; 95% CI, 0.74-1.13; P = 0.41; I2 = 0%). Two PSM studies also revealed no significant difference in 5-y overall survival (OS) between groups (RR, 0.77; 95% CI, 0.52-1.13; P = 0.18; I2 = 47%).
The results of these meta-analyses show that omentectomy had no significant influence on 5-y OS, especially 5-y RFS, in patients with LAGC.

Excess visceral adipose tissue has been identified as an important risk factor for obesity-related co-morbidities. Conflicting information exists on whether omentectomy added to bariatric surgery is beneficial to metabolic variables.
To evaluate the impact of omentectomy added to bariatric surgery on metabolic outcomes SETTING: University Hospital, Canada.
MEDLINE, EMBASE, and PubMed were searched up to May 2018. Studies were eligible for inclusion if they were randomized controlled trials comparing omentectomy added to bariatric surgery with bariatric surgery alone. Primary outcome measures were absolute change in metabolic variables (body mass index, insulin, glucose, cholesterol, lipoproteins, and triglycerides); secondary outcomes were changes in adipocytokines. Pooled mean differences (mean deviation; MD) were calculated using random effects meta-analyses, and heterogeneity was quantified using the I2 statistic.
Ten trials involving a total of 366 patients met the inclusion criteria with a median follow-up time of 1 year after surgery. Adding omentectomy to bariatric surgery demonstrated a minimal but statistically significant decrease in body mass index compared with bariatric surgery alone (MD 1.29, 95% confidence interval .35-2.23, P = .007, I2 = 0%, 10 trials). Conversely, patients who underwent bariatric surgery alone had significant increases in high-density lipoprotein (MD -2.12, 95% confidence interval -4.13 to -.11, P = .04, I2 = 0%, 6 trials). Other metabolic outcomes and adipocytokines showed no significant difference between procedures.
The addition of omentectomy to bariatric surgery results in minimal reduction of body mass index. Considering no overall improvement in metabolic outcomes and the time and effort required, the therapeutic use of omentectomy added to bariatric surgery is not warranted.