Impact of the vertical division of the rectum on the decrease in reloading of the endostapler for a complete division in colorectal cancer

Background: Despite several improvements in surgical techniques, the intracorporeal division of the distal end of the rectum is still challenging, particularly when it is too deep in a narrow pelvis. Even though it helps avoid spillage, the double-stapling technique (DST) raises concerns regarding safety and anastomotic leakage if multiple stapler firings are essential to complete the rectal division. Objective: To assess the feasibility of vertically dividing the rectum and its impact in reducing the number of reloads essential for that division in non-low rectal cancer patients undergoing total mesorectal excision (TME). Materials and Methods A retroprospective study. Results: From January 2017 to November 2021, a total of 123 patients with sigmoid and rectal cancers were enrolled in the present study; their data were collected and analyzed, and 21 patients were excluded. The remaining sample of 102 subjects was composed of 47 male (46%) and 55 female (54%) patients with a median age of 54 years (range: 30 to 78 years). Only 1 reload was enough to complete the rectal division in 82 (80.39%) cases, and 2 reloads were used in the remaining 20 (19.61%) patients. Anastomotic leakage was clinically evident in 4 cases (3.9%). No statically significant difference was observed when firing one or two staplers. No 30-day mortality was recorded in this series. Conclusion: Our early experience indicates that this type of division has a real advantage in terms of decreasing the number of reloads needed and, in turn, lowering the incidence of anastomotic leakage after partial mesorectal excision (PME) or TME when applied with proper patient selection. (AU)

Malignant gastrointestinal neuroectodermal tumor: a case report and review of the literature.

BACKGROUND: Malignant gastrointestinal neuroectodermal tumor (GNET) is an extremely rare entity that was first described by Zambrano et al. in 2003 as "Clear cell sarcoma-like tumor of the gastrointestinal tract". It shares some of the histological features of clear cell sarcoma (CCS) but lacks the immunohistochemical reactivity for melanocytic markers. We report a case of GNET that was initially misdiagnosed as gastrointestinal stromal tumor (GIST). Recognizing this entity is important to avoid misdiagnosis. CASE PRESENTATION: A case of an 18-year-old male presented with a small intestinal tumor. Histologically it was characterized by polygonal cells arranged in pseudoalveolar pattern and situated in the muscularis propria. Scattered osteoclast-like multinucleated giant cells were also noted. The neoplastic cells were positive for S-100 protein and negative for HMB-45, Melan A, smooth muscle actin, desmin and CD117. EWSR1 gene rearrangement was detected by fluorescence in situ hybridization (FISH) analysis. The patient returned with recurrence after 36 months' management by surgical resection and died one year later. CONCLUSIONS: GNET can be mistaken histologically for other non-epithelial gastrointestinal tumors. Awareness of its existence and diagnostic criteria by the pathologist is necessary to avoid misdiagnosis, particularly as GIST, CCS or malignant peripheral nerve sheath tumor (MPNST).

Preoperative intravitreal bevacizumab use as an adjuvant to diabetic vitrectomy: histopathologic findings and clinical implications.

PURPOSE: To evaluate the effects of intervals between preoperative intravitreal injection of bevacizumab (IVB) and surgery on the components of removed diabetic fibrovascular proliferative membranes. DESIGN: Interventional, consecutive, prospective, comparative case series. PARTICIPANTS: A total of 52 eyes of 49 patients with active diabetic fibrovascular proliferation with complications necessitating vitrectomy. METHODS: Participant eyes that had IVB were divided into 8 groups in which vitreoretinal surgery was performed at days 1, 3, 5, 7, 10, 15, 20, and 30 postinjection. A group of eyes with the same diagnosis and surgical intervention without IVB injection was used for comparison. In all eyes, proliferative membrane specimens obtained during vitrectomy were sent for histopathologic examination using hematoxylin-eosin stain, immunohistochemistry (CD34 and smooth muscle actin), and Masson's trichrome stain. MAIN OUTCOME MEASURES: Comparative analysis of different components of the fibrovascular proliferation (CD34, smooth muscle actin, and collagen) among the study groups. RESULTS: Pan-endothelial marker CD34 expression levels starting from day 5 postinjection were significantly less than in the control group (P < 0.001), with minimum expression (1+) in all specimens removed at or after day 30 postinjection. Positive staining for smooth muscle actin was barely detected in the control eyes at day 1, and consistently intense at day 15 and beyond (P < 0.001). The expression level of trichrome staining was significantly high at day 10, compared with control eyes (P < 0.001), and continued to increase at subsequent surgical time points. CONCLUSIONS: A profibrotic switch was observed in diabetic fibrovascular proliferation after IVB, and our results suggest that at approximately 10 days post-IVB the vascular component of proliferation is markedly reduced, whereas the contractile components (smooth muscle actin and collagen) are not yet abundant.