Permanent Flank Bulge after Flank Incision: Patient- and Physician-Reported Outcome

Introduction: The aim of this study was to determine the incidence and risk factors for postoperative flank bulging and associated physiologic/psychologic consequences as well as to establish a clinical flank bulge classification system after open retroperitoneal surgery. Methods: In this retrospective study, a postal patient survey was sent to 240 patients who underwent open retroperitoneal surgery between 2007 and 2017. Patients, who reported a flank bulge, were invited for further evaluation, which included a clinical examination and standardized photo documentation. Results: Forty-three of 120 patients (35.8%) reported a flank bulging after retroperitoneal surgery. During clinical examination, a flank bulge could be confirmed in 25 patients, whereas in 18 patients, no bulging could be detected, leading to a corrected rate of flank bulge-positive patients of 20.8%. The corresponding relaxation values ranged from 1 to 1.44 and correlated with the clinical degree of bulging. A body mass index of >= 25 was identified as a risk factor. No correlation was found regarding age, gender, surgery side, access to the retroperitoneum, surgical procedure, and pathology. Thirty-seven patients complained about chronic pain or suffered from the cosmetic impact of bulging. Thirteen of those patients had shown a flank bulge during clinical examination, resulting in a symptomatic bulge rate of 10.8% (13/120 patients). Conclusion: Chronic pain and postoperative flank bulging are 2 of the most common long-term complications after open retroperitoneal access. If an open retroperitoneal approach is required, particularly obese patients should be thoroughly informed about the risk of flank bulging and chronic pain.