BACKGROUND: Patients receiving allogenic hematopoietic stem cell transplant (HSCT) may experience intestinal graft versus host disease (GVHD). Intestinal GVHD is typically managed with medical therapy but surgery and angioembolization may be warranted in selected patients with complicated intestinal GVHD. METHODS: The following complications that warrant surgical consultation were identified: severe bleeding, bowel stricture or obstruction, intestinal pneumatosis and intestinal perforation. Patients diagnosed with complicated intestinal GVHD between 2010 and 2024 were retrospectively retrieved. Need for surgery and interventional radiology, mortality related to GVHD and chronic intestinal failure (CIF), defined as need for total parenteral nutrition (TPN) for more than six months or until exitus, were described. RESULTS: Eighteen patients had complicated intestinal GVHD. Fourteen (78%) had severe bleeding, with a GVHD-related mortality rate of 64% and CIF prevalence of 86%: one had angioembolization of one distal branch of superior mesenteric artery for refractory bleeding, and finally died for hepatic GVHD. Eight patients (39%) had bowel stricture, with a GVHD-related mortality rate of 50% and CIF prevalence of 75%. Four patients underwent laparotomy and bowel resection for critical stricture causing obstruction, in one case at the site of previous biopsy; two (50%) died as a consequence of GVHD, and both survivors had multiple laparotomies and eventually developed CIF. Three patients (17%) had pneumatosis; none evolved to intestinal perforation and all were all successfully treated conservatively with careful monitoring, TPN and immunosuppression. One of them (33%) eventually died for hepatic GVHD and pulmonary aspergillosis. In the whole cohort, GVHD-related mortality rate was 61% and prevalence of CIF was 78%. CONCLUSION In patients affected by complicated intestinal GVHD, uncontrolled bleeding and critical stricture causing bowel obstruction are indication for angioembolization and surgery, while pneumatosis can be treated conservatively. Given the severity of complicated intestinal GVHD, a high risk of mortality and CIF should be anticipated.

Nephron sparing surgery (NSS) is a standard technique for patients with bilateral Wilms tumor (WT) and unilateral WT with predisposing syndromes. The decision for intra-operative ureteral stent placement depends on the degree of disruption of the collecting system and must be balanced between the risk of post-operative urinary leak and the risk of stent-related urinary tract infection. The purpose of this study is to find predictors of urinary leak that may guide the decision for ureteral stenting. Methods Patients who underwent NSS for pre-operative diagnosis of renal masses at a single tertiary pediatric hospital between January 2010 and December 2023 were retrospectively reviewed. Exclusion criteria were post-operative diagnosis of non-neoplastic conditions and incomplete data. The following pre-operative variables were studied: laterality of the tumor, symptoms at diagnosis, timing of surgery, pre-operative chemotherapy toxicity grade 3 or higher according to the Common Terminology Criteria for Adverse Events (CTCAE; version 5.0). Three intra-operative variables were studied: the need for intra-operative repair of distal calyces, total duration of surgery and duration of vascular clamping. Primary outcome was the occurrence of urinary leak. Secondary outcomes were post-operative renal dysfunction and post-operative length of hospitalization. Results Thirty-seven patients underwent NSS; seven of them were excluded for post-operative diagnosis of non-neoplastic disease or incomplete data. Twenty patients had unilateral disease and ten had bilateral disease or tumor on horseshoe kidney. Eight patients underwent upfront surgery and twenty-two received neoadjuvant chemotherapy. Ureteral stent was placed intra-operatively in three patients (10%). Urinary leakage was observed in four patients (13%) who did not undergo intraoperative stenting; all of them required delayed stent placement. Urinary leak was significantly associated with pre-operative chemotherapy toxicity (4/10 patients versus 0/20 patients, p = 0.0077). Post-operative renal dysfunction was significantly associated with pre-operative chemotherapy toxicity (8/10 patients vs 3/20 patients; p = 0.0010), bilateral disease (7/10 patients vs 4/20 patients; p = 0.0147) and surgery after neoadjuvant chemotherapy (11/22 patients vs 0/8 patients; p = 0.0140). Post-operative hospitalization was significantly longer in patients with pre-operative chemotherapy toxicity (median 10.5 days versus 7 days, p = 0.0255) and in patients who underwent s