Background and Aims 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 surgery after neoadjuvant chemotherapy (median 9.5 days versus 6.5 days, p = 0.0053). Conclusions Patients with a history of severe pre-operative chemotherapy toxicity have a higher risk of post-operative urinary leak after NSS. In these patients planned intra-operative ureteral stenting should be considered.

Background and aims Patients affected by metastatic germ cell tumors may occasionally experience enlargement of metastatic lesions with concurrent normalization of tumor markers after chemotherapy. This phenomenon is described as Growing Teratoma Syndrome (GTS). The aim of the present study is to assess the prevalence of GTS in the pediatric population and its implications in terms of surgical outcome. Methods The clinical notes of patients diagnosed with stage III and IV malignant germ cell tumors from January 2010 until December 2020 at our Institution were retrospectively reviewed. Patients with residual disease after chemotherapy were studied; the occurrence of GTS, treatment strategies, survival and outcome were analyzed. Results Thirty-three patients with high stage malignant germ cell tumors were diagnosed in our Institution in the analyzed period. Eleven patients (34%) had radiologic evidence of enlargement of metastases after chemotherapy; nine of them (28%) had normal markers after chemotherapy and were classified as GTS patients. All nine patients underwent resection of metastatic lymph nodes and six had surgery on visceral metastases. In six patients, radical excision of all metastatic sites was achieved; five patients are alive and in complete remission while one died for peri-operative complications. Out of the three patients who could not achieve radical excision of the metastases, two died for progressive disease and one is alive with progressive disease. Conclusions Patients affected by GTS have a risk of progression of chemotherapy-resistant disease and death. Radical surgical excision is essential to achieve disease control and long-term survival.

Thoracic air leak syndrome (TALS) is a complication related to chronic pulmonary graft-versus-host disease (pGvHD) and is defined as the occurrence of any form of air leak in the thorax. Four patients, aged 16 to 25 years, underwent surgical procedures for TALS between January 2016 and March 2021. All the patients experienced at least two episodes before surgery. After surgery, patients were temporarily free from air leak symptoms. All the patients eventually died because of respiratory failure. Surgery provides temporary relief to symptoms related to TALS. When TALS develops, pulmonary function progressively worsens toward respiratory failure and death.