Surgical complications after primary nephrectomy for Wilms' tumor: Report from the National Wilms' Tumor Study Group

BACKGROUND: Surgical complications are a recognized morbidity of the treatm ent of patients with Wilms tumor. This study examines the incidence of surg ical complications in the most recently completed study from the National W ilms' Tumor Study Group (NWTSG). STUDY DESIGN: The fourth National Wilms' Tumor Study (NWTS-4) enrolled 3,33 5 patients from August 1986 to August 1994. A random sample of 534 patients was selected from 2,290 eligible patients randomized to treatment regimens or enrolled in the followed category and treated according to NWTSG protoc ol. The patient records received at the NWTSG Data and Statistical Center w ere analyzed for surgical complications (intraoperative and postoperative). RESULTS: Sixty-eight patients (12.7%) experienced 76 complications. Intesti nal obstruction was the most common complication (5.1% of patients), follow ed by extensive hemorrhage (1.9%), wound infection (2.9%), and vascular inj ury (1.5%). The incidence of surgical complications in NWTS-4 was significa ntly lower than NWTS-3 (12.7% versus 19.8%, p < 0.001). There has been a ma rked decrease in the risk of extensive intraoperative bleeding and major in traoperative complications. Factors previously shown to be associated with an increased risk for surgical complications, together with indicators of t ype of hospital and surgeon specialty, were analyzed by multiple logistic r egression analysis. Intravascular extension into the inferior vena cava (IV C), the atrium, or both (p = 0.02; odds ratio [OR] 3.8, 95% confidence inte rval [CI] 1.2, 11.8), and nephrectomy performed through a flank or paramedi an incision (p = 0.02; OR 5.3, 95% CI 1.3, 22) were both associated with in creased risk of complications. Tumor diameter greater than or equal to 10 c m was also associated with an increased risk of surgical complications (p = 0.05; OR 2.0, 95% CI 1.0, 3.9). The risk of complications was higher if th e nephrectomy was performed by a general surgeon (OR 9.0, 95% CI 1.3, 65; p = 0.03) rather than a pediatric surgeon (reference group, OR 1.0) or pedia tric urologist (OR 0.7, 95% CI 0.3, 1.8). CONCLUSIONS: The incidence of surgical complications in NWTSG patients unde rgoing primary nephrectomy has significantly decreased over the past decade . But surgical morbidity should not be overlooked. It is important that sur geons treating young children with solid tumors are aware of their role and the potential risks encountered in removal of the primary tumor. This stud y found that surgical specialists who primarily treat children can perform these operations with lower surgical morbidity. (J Am Coll Surg 2001;192:63 -68. (C) 2001 by the American College of Surgeons).