The Peritoneum: Anatomy, Pathologic Findings, and Patterns of Disease Spread.

Disease spread in the abdomen and pelvis generally occurs in a predictable pattern in relation to anatomic landmarks and fascial planes. Anatomically, the abdominopelvic cavity is subdivided into several smaller spaces or compartments by key ligaments and fascial planes. The abdominal cavity has been traditionally divided into peritoneal, retroperitoneal, and pelvic extraperitoneal spaces. Recently, more clinically relevant classifications have evolved. Many pathologic conditions affect the abdominal cavity, including traumatic, inflammatory, infectious, and neoplastic processes. These abnormalities can extend beyond their sites of origin through various pathways. Identifying the origin of a disease process is the first step in formulating a differential diagnosis and ultimately reaching a final diagnosis. Pathologic conditions differ in terms of pathways of disease spread. For example, simple fluid tracks along fascial planes, respecting anatomic boundaries, while fluid from acute necrotizing pancreatitis can destroy fascial planes, resulting in transfascial spread without regard for anatomic landmarks. Furthermore, neoplastic processes can spread through multiple pathways, with a propensity for spread to noncontiguous sites. When the origin of a disease process is not readily apparent, recognizing the spread pattern can allow the radiologist to work backward and ultimately arrive at the site or source of pathogenesis. As such, a cohesive understanding of the peritoneal anatomy, the typical organ or site of origin for a disease process, and the corresponding pattern of disease spread is critical not only for initial diagnosis but also for establishing a road map for staging, anticipating further disease spread, guiding search patterns and report checklists, determining prognosis, and tailoring appropriate follow-up imaging studies. ©RSNA, 2024 Supplemental material is available for this article.

[Pleuroperitoneal Communication Using Intraoperative Imaging with Indocyanine Green Fluorescence: Report of a Case].

A 46-year-old man was treated with ascites due to idiopathic portal hypertension. Chest X-ray showed a massive pleural effusion on the right side. Also, contrast-enhanced ultrasonography showed that contrast medium was effusing from abdominal cavity into the thoracic cavity via diaphragm. He was diagnosed with pleuroperitoneal communication. Thoracoscopic surgery was performed and thoracoscope revealed ascites with indocyanine green (ICG) drained from multiple cystic area in the central tendon of the diaphragm. After suturing with non-absorbable thread with reinforcement, the whole diaphragm was covered with a polyglycolic acid sheet and fibrin glue. Postoperatively, there was no reaccumulation of pleural effusion. ICG fluorescence intraoperative imaging was an useful method in detecting the pleural holes.

Prevention of peritoneal adhesions after gynecological surgery: a systematic review.

IMPORTANCE: The formation of adhesions after gynecological surgery not only has detrimental impacts on those affected, including pain, obstruction, and infertility, but also imposes a high economic burden on healthcare systems worldwide. OBJECTIVE: The aim of this review was to evaluate the adhesion prevention potential of all currently available adhesion barriers for gynecological surgery. EVIDENCE ACQUISITION: We systematically searched MEDLINE and CENTRAL databases for randomized controlled trials (RCTs) on the use of adhesion barriers as compared with peritoneal irrigation or no treatment in gynecological surgery. Only RCTs with second-look surgery to evaluate adhesions in the pelvic/abdominal (but not intrauterine) cavity were included. RESULTS: We included 45 RCTs with a total of 4,120 patients examining a total of 10 unique types of barriers in second-look gynecological surgery. While RCTs on oxidized regenerated cellulose (significant improvement in 6 of 14 trials), polyethylene glycol with/without other agents (4/10), hyaluronic acid and hyaluronate + carboxymethylcellulose (7/10), icodextrin (1/3), dextran (0/3), fibrin-containing agents (1/2), expanded polytetrafluoroethylene (1/1), N,O-carboxymethylchitosan (0/1), and modified starch (1/1) overall showed inconsistent findings, results for expanded polytetrafluoroethylene, hyaluronic acid, and modified starch yielded the greatest improvements regarding adhesion reduction at 75%, 0-67%, and 85%, respectively. CONCLUSIONS AND RELEVANCE: Best results for adhesion prevention were reported after applying Gore-Tex Surgical Membrane, hyaluronic acid, and 4DryField®. As Gore-Tex Surgical Membrane is nonabsorbable, it is associated with a greater risk of new adhesion formation due to second-look surgery to remove the product. 4DryField® yielded the greatest improvement in adhesion score compared to all other barrier agents (85%). For better comparability, future studies should use standardized scores and put more emphasis on patient-reported outcome measures, such as pain and infertility.

Laparoscopically treated bowel obstruction secondary to a lesser omental hernia resulting from a previous laparoscopic total colectomy for ulcerative colitis: A report of two cases.

Lesser omental hernias are rare; however, they should be considered in symptomatic bowel obstruction subsequent to a subtotal or total colectomy. This report describes two cases of recurrent bowel obstruction secondary to lesser omental hernias after laparoscopic total colectomies for ulcerative colitis. Initially, these patients had been treated conservatively; however, due to symptom recurrence, surgical intervention was decided on. In both cases, laparoscopic surgery revealed lesser omental hernias. The small bowel, which had entered from the dorsal aspect of the stomach, was returned to the original position, and the lesser omentum was closed. The patients were discharged uneventfully, with no recurrent bowel obstruction during the follow-up period. These cases highlight the importance of including internal hernias in the differential diagnosis relative to recurrent bowel obstruction, in patient subpopulations with a prior history of a subtotal or total colectomy. Confirmation by computed tomography is preferable.

An indocyanine green fluorescence-guided operation for diagnosing and treating pleuroperitoneal communication.

Pleuroperitoneal communication occurs when ascites moves from the abdominal cavity to the pleural cavity via a diaphragmatic fistula. Managing large pleural fluid volumes is challenging, often requiring an operation. Identifying small diaphragmatic fistulas during the operation can be problematic, but ensuring their detection improves outcomes. This video tutorial presents a recent empirical case in which we successfully identified and closed a pleuroperitoneal contact using a thoracoscopic surgical procedure aided by indocyanine green fluorescence imaging. The patient, a 66-year-old woman, was hospitalized due to acute dyspnoea from a right thoracic pleural effusion during hepatic ascites treatment for cirrhosis. Because ascites decreased with pleural fluid drainage, surgical intervention was considered due to suspicion of a pleuroperitoneal connection. During the operation, indocyanine green was injected intraperitoneally, and near-infrared fluorescence-guided thoracoscopy pinpointed the location of the diaphragmatic fistula. The fistula was sutured and reinforced with a polyglycolic acid sheet and fibrin glue. Detecting the fistula intraoperatively is crucial to prevent recurrence, and the indocyanine green fluorescence method is a safe and effective technique for detecting small fistulas.

Large and Extensive Multilocular Peritoneal Inclusion Cysts Lack Genomic Alterations and Follow an Indolent Clinical Course Despite Rare Recurrences.

Peritoneal inclusion cysts (PICs) are unilocular or multilocular cystic lesions lined by bland mesothelial cells. While most are small and localized, rare examples may be large or multifocal with diffuse peritoneal involvement, causing clinical and even pathologic concern for malignancy. We examined 20 PIC, including 8 large solitary and 12 multifocal lesions. Solitary PIC were found in 7 female and 1 male patients ranging from 19 to 55 (median: 37) years. Expanded collagenous (n=2) or edematous (n=1) areas were occasionally seen in the septae, and 1 had microscopic foci of myxoid stroma. Four had hobnail cells, and 1 had minor areas of papillary mesothelial hyperplasia. Multifocal PICs occurred in 9 female and 3 male patients ranging from 26 to 80 (median: 53) years. Three showed extensive associated fibrosis with entrapment of preexisting adipose tissue, 2 had areas resembling granulation tissue, and 3 had scattered foci of myxoid stroma. Hobnail cells were present in 9, papillary mesothelial hyperplasia in 2, entrapped single cells in 1, and 2 had areas resembling adenomatoid tumors. Two of the multifocal PICs had limited local recurrences at 18 and 21 months. No patients died of disease. Clonal alterations were not identified in any of the tested PICs (mutational and fusion analysis in 5, chromosomal microarray in 1). Despite limited local recurrences, we demonstrate that even large and multifocal PICs may lack identifiable genomic alterations and are associated with benign outcomes.

Comparison of the effect of Everolimus, Prednisolone, and a combination of both on experimentally induced peritoneal adhesions in rats.

Postoperative intra-abdominal adhesions represent a significant post-surgical problem. Its complications can cause a considerable clinical and cost burden. Herein, our study aimed to investigate the effect of Everolimus on peritoneal adhesion formation after inducing adhesions in rats. In this experimental study, adhesion bands were induced by intraperitoneal injection of 3 ml of 10% sterile talc solution in 64 male albino rats. The first group served as the control group. The second one received oral Prednisolone (1 mg/kg/day), the third received Everolimus (0.1 mg/kg/day), and group four received both drugs with similar dosages for four consecutive weeks. The formation of adhesion bands was qualitatively graded according to the Nair classification. The rats in the control group had extensive adhesions between the abdominal wall and the organs. Regarding substantial adhesion formation, 50% (8/16) of animals in the control group had substantial adhesions, while this rate in the groups receiving Prednisolone, Everolimus, and combination treatment was 31%, 31%, and 31%, respectively. Also, 68.75% (5/11) of the Prednisolone recipients had insubstantial adhesions, the same as Everolimus recipients, while in the combination group, 66.66% (10/15) rats had insubstantial adhesions. Everolimus demonstrated satisfactory results in reducing the rates of induced peritoneal adhesion in an experimental model, similar to Prednisolone and superior to a combination regime.

Primary Omental Torsion in Children in the Laparoscopy Era: What Have we Learned so far?

BACKGROUND/AIM: Primary omental torsion is uncommon, mimicking appendicitis and other acute abdominal pathologies. It often escapes diagnosis on imaging investigation or conventional open laparotomy. This study aimed to evaluate the effect of laparoscopy on the various parameters of this entity, including incidence, diagnosis, and treatment. MATERIALS AND METHODS: A systematic review was performed, including PubMed and Scopus databases, without a time limit, following the PRISMA principles. A total of 16 articles from January 2000 to December 2023, corresponding to 56 children with primary omental torsion, complied with the research criteria. RESULTS: Primary omental torsion was associated with obesity. Symptoms were right abdomen oriented, often compared to those of acute appendicitis. Preoperative ultrasound displayed low diagnostic accuracy, whereas computerized tomography diagnosed only two thirds of cases. In all patients, the vermiform appendix was normal. CONCLUSION: Laparoscopy affected both diagnosis and treatment of primary omental torsion in children. Easy peritoneal cavity access rendered possible the diagnosis of cases previously discharged as abdominal pain of unknown etiology. Combined with the increased pediatric obesity, it also affected primary omental torsion incidence. The recent pathogenetic theories may be better supported today, as laparoscopy provides a detailed view in situ, and facilitates harvesting of fat tissue from the omentum for molecular investigation. The diagnostic efficiency of laparoscopy is superior to ultrasonography and computerized tomography. Finally, the removal of the ischemic omentum is technically easier compared to the open laparotomy alternative with all the technical difficulties of traction of a vulnerable hemorrhagic tissue through a small incision.

Giant intraperitoneal non-pancreatic pseudocyst: a case report.

INTRODUCTION: Non-pancreatic pseudocysts are rare lesions that typically form from the omentum and mesentery. These cysts have a thick fibrotic wall made up of fibrous tissue and may show signs of calcifications and inflammatory changes. The fluid inside them can vary, ranging from hemorrhage and pus to serous or sometimes chylous content. In most cases, these cysts appear as a result of trauma, surgery, or infection. CASE PRESENTATION: A 35-year-old male patient from Ethiopia presented with swelling in his lower abdomen that had been present for 2 years. Initially, the swelling was small but gradually increased in size. The patient experienced frequent urination but no pain or difficulty during urination, urgency, intermittent urination, or blood in the urine. The swelling was initially painless but became painful 2 months prior to his presentation. Abdominal computed tomography scans revealed a well-defined, lobulated peritoneal lesion measuring 16 × 12 × 10 cm, consisting primarily of fluid-filled cysts with a thick, enhancing wall and septa. Additionally, there was a large, heterogeneous enhancing soft tissue component measuring 8 × 6 cm. As a result, the cystic mass was surgically removed in its entirety with partial removal of the bladder wall, and the patient was discharged in an improved condition. CONCLUSION: Primary non-pancreatic pseudocysts are extremely rare lesions that must be differentiated from other possible causes of cystic lesions within the peritoneal or retroperitoneal regions. Surgeons should be aware of the potential occurrence of these lesions, which may have an unknown origin.

Prediction of Intraperitoneal Adhesions in Repeated Cesarean Deliveries with Stria Gravidarum Scoring System: A Cross-sectional Study.

BACKGROUND: The preoperative prediction of intraperitoneal adhesion (IPA) before repeated cesarean deliveries (CD), which are becoming more prevalent, is crucial for maternal health. AIM: The aim of the study was to preoperatively predict IPA in repeated CD with the stria gravidarum (SG) scoring system. METHODS: A total of 167 patients with at least one previous CD at or beyond 37 weeks of gestation were analyzed. Preoperative SG was calculated according to the Davey scoring system: 0-2 score were defined as mild SG (Group 1; n: 94, 56.2%), and 3-8 score were defined as severe SG (Group 2; n = 73, 43.8%). Preoperative previous cesarean incision features were evaluated according to the Vancouver scar scale. IPA was evaluated according to the Nair's and modified Nair's scoring systems. RESULTS: Parity, younger age at first pregnancy, higher body mass index, number of previous CDs, rate of scar symptoms, Nair's and the modified Nair's scores were statistically significant in Group 2 (P = 0.01; P = 0.04; P = 0.007; P = 0.004; P < 0.001; P = 0.007; P = 0.02, respectively). Davey score ≥3 and Vancouver score ≥4.5 were determined as the cut-off value to predict IPA (P = 0.1 and 0.07, respectively). According to multivariate analysis, both Davey and Vancouver scores are independent factors in predicting IPA (P = 0.02 and 0.04, respectively). CONCLUSION: Evaluating the SG score through the Davey score in women with a history of previous CD may assist in predicting IPA status before the planning of a subsequent surgery.

Unusual case of retroperitoneal hematoma and duodenal ulcerative bleeding after nephrectomy: Case report.

RATIONALE: Retroperitoneal hematomas are relatively common in patients undergoing nephrectomy. Herein, we report an unusual case involving a giant retroperitoneal hematoma and subsequent duodenal ulcerative bleeding following a radical nephrectomy. PATIENT CONCERNS: A 77-year-old woman was admitted to our hospital for lower back pain, and she had severe right hydronephrosis and a urinary tract infection. DIAGNOSES: The patient was diagnosed and confirmed as high-grade urothelial carcinoma. INTERVENTIONS: After ineffective conservative treatments, a right radical nephrectomy and ureteral stump resection were performed. The patient received proton pump inhibitors to prevent stress ulcer formation and bleeding. On the first day post-surgery, she had normal gastrointestinal (GI) endoscopy findings. On the second day post-surgery, abdominal computed tomography revealed a retroperitoneal hematoma. Notably, 14 days post-surgery, massive GI bleeding occurred, and GI endoscopy identified an almost perforated ulcer in the bulbar and descending duodenum. OUTCOMES: The patient died on day 15 after surgery. LESSONS: Duodenal ulceration and bleeding might occur following a retroperitoneal hematoma in patients treated with nephrectomy. Timely intervention may prevent duodenal ulcers and complications, and thus could be a promising life-saving intercession.

Giant peritoneal loose body and its protein composition: a case report.

Peritoneal loose body (PLB) is a kind of lesions located in the abdominal cavity or pelvic cavity, which is rare and difficult to diagnose. The diameter of PLB is mostly 0.5-2.5 cm. Most PLBS are asymptomatic. Here we reported a case of giant PLB in the pelvis and analyzed its structure and protein composition. Surgical exploration revealed a white oval mass (4.5*4*3 cm) in the pelvic cavity. After the mass was removed, the symptoms of hematuria disappeared and the patient was discharged on the second postoperative day. Histochemical staining showed that PLB was mainly composed of collagen and scattered calcification. The protein components of PLB were detected by proteome analysis, and a variety of proteins related to collagen deposition and calcification were identified in PLB.

Inhibition of chemokine receptor CXCR2 attenuates postoperative peritoneal adhesion formation.

BACKGROUND: Postoperative peritoneal adhesions remain a problem after general and gynecological surgery. METHODS: Hematoxylin and eosin and Masson's trichrome staining of ischemic buttons were performed 6, 12, 24 hours, and 7 days after button induction. Scanning electron microscopy, ribonucleic acid sequencing, quantitative real-time polymerase chain reaction, immunohistochemical staining, and flow cytometry were used to elucidate the pathophysiology of postoperative peritoneal adhesions. RESULTS: The results showed that thickening of the peritoneum and abscission of mesothelial cells and collagen fibers increased significantly on the surface of the "button" in the control groups at 24 hours postoperatively. Scanning electron microscopy revealed a large number of granulocytes on the button surface in the control group at 24 hours. Ribonucleic acid sequencing and quantitative real-time polymerase chain reaction also revealed that CXCR2 expression was significantly upregulated. In addition, danirixin, a CXCR2 inhibitor, reduced abdominal adhesion in the injured area by inhibiting the infiltration of inflammatory cells and collagen production. Immunohistochemical staining showed decreased expression of CXCR2 in the adhesion area 7 days after surgery in the treatment group. Flow cytometry showed a significantly decreased neutrophil ratio in the treatment group compared with that in the control group 24 hours after the operation. CONCLUSIONS: Inflammation plays an important role in the early stages of postoperative peritoneal adhesion formation, whereas collagen fibers and angiogenesis play important roles in the late stages. The CXCL2-CXCL3-CXCR2 signaling axis is an important link in the mechanism of postoperative peritoneal adhesion formation, and the application of CXCR2 inhibitors can alleviate the formation of postoperative peritoneal adhesions.

Effects of linalool on postoperative peritoneal adhesions in rats.

The current study examines the effects of linalool in preventing postoperative abdominal adhesions. Twenty male Wistar rats were randomly divided into four groups. (1) Sham: in this group, the abdomen was approached, and without any manipulations, it was sutured. (2) Control: rats in this group underwent a surgical procedure to induce adhesions. This involved making three incisions on the right abdominal side and removing a 1×1-cm piece of the peritoneum on the left abdominal side. (3) Treatment groups: these groups underwent the same surgical procedure as the control group to induce adhesions. Animals in these groups received linalool orally with doses of 50 and 100 mg/kg, respectively, for a period of 14 days. Moreover, rats in the sham and control groups received normal saline via gavage for 14 days. The evaluation of TNF-α, TGF-ß, VEGF, and caspase 3 was performed using western blot and IHC methods. Furthermore, oxidative stress biomarkers such as MDA, TAC, GSH, and NO were assessed in the peritoneal adhesion tissue. The findings revealed that linalool significantly reduced peritoneal adhesions by reducing TNF-α, TGF-ß, VEGF, and caspase 3 levels. Moreover, MDA concentration was significantly decreased, while NO, TAC, and GSH levels were notably increased. Overall, linalool was effective in preventing adhesion formation and reduced inflammation, angiogenesis, apoptosis, and oxidative stress. Therefore, linalool as a potent antioxidant is suggested for reducing postoperative adhesions in rats.

Distribution of smooth muscle actin and collagen in superficial peritoneal endometriotic lesions varies from the surrounding microenvironment.

RESEARCH QUESTION: Do different subtypes of superficial peritoneal endometriotic lesions exist, based on the presence and morphology of smooth muscle, collagen fibres and immune cell populations? DESIGN: A retrospective cohort study of 24 patients, from across the menstrual cycle, with surgically and histologically confirmed endometriosis. Immunofluorescence was used to delineate the CD10 stromal area of lesions (n = 271 lesions from 67 endometriotic biopsies), and then smooth muscle actin (SMA) positive tissue and immune cell populations (CD45+ and CD68+) were quantified within and adjacent to these lesions. Second harmonic generation microscopy was used to evaluate the presence and morphology of type-1 collagen fibres within and surrounding lesions. RESULTS: Overall, immune cell numbers and the area of SMA and collagen within endometriotic lesions tended to be low, but a spectrum of presentations significantly varied, particularly in the adjacent tissue microenvironment, based on lesion locations, the morphology of endometriotic gland profiles, or both. Lesions in which collagen fibres formed well aligned capsules around the CD10+ stromal border were identified compared with lesions in which collagen fibre distribution was random. Considerable inter- and intra-patient variability in the morphology of SMA and collagen was observed within and surrounding lesions. CONCLUSION: These data demonstrate considerable diversity in the presence of immune cells and morphology of SMA and collagen within, but even more so, surrounding endometriotic lesions, even within individual patients. This heterogeneity, especially within individual patients, presents a challenge to incorporating these cell and tissue types into any new endometriosis classification systems or prognostic approaches.