ABSTRACT
Acute kidney injury (AKI) is a serious complication after vascular surgery. Reduced synthesis of nicotinamide adenine dinucleotide (NAD+) from tryptophan is associated with an increased risk of AKI in critically ill patients, patients hospitalized with COVID-19, and cardiac surgery patients, and is marked by elevated urinary quinolinate and quinolinate to tryptophan ratios. We measured quinolinate concentrations in vascular surgery patients to determine if impaired NAD+ synthesis was associated with AKI in this patient population. Eight preoperative and eight postoperative vascular surgery patients who developed AKI were selected from a parent study to participate in this single-center case-control study. They were matched with controls who did not develop AKI based on age, sex, BMI, eGFR, hypertension, and diabetes. Urinary quinolinate and tryptophan concentrations were measured at anesthetic induction and on postoperative day one. Two-sided Mann-Whitney U tests were used to compare quinolinate and quinolinate to tryptophan ratios. Multivariate linear regression modeling was used to estimate the relationship between quinolinate and serum creatinine. There was no difference in preoperative or postoperative urine quinolinate concentrations or the preoperative quinolinate to tryptophan ratio between patients that did and did not develop AKI (p = 0.07, 0.50, and 0.32, respectively). However, postoperative quinolinate to tryptophan ratios were higher in AKI patients (p = 0.04). Further, after adjustment for AKI risk factors, higher preoperative quinolinate concentrations and higher postoperative quinolinate to tryptophan ratios were associated with greater postoperative creatinine increases (p = 0.04 and 0.04, respectively). These data suggest that impaired NAD+ synthesis may contribute to AKI development in vascular surgery patients.
ABSTRACT
INTRODUCTION: Lymphangiomas are rare, cystic tumors that represent congenital malformation of the lymphatic vessels. We reviewed our institution's experience treating abdominal lymphangiomas with the purpose of describing the clinical features, management, and outcomes of this rare pathology. METHODS: This is a single-institution, institutional review board-approved retrospective review of abdominal lymphangiomas presenting between January 2010 and February 2021. The diagnosis of lymphangioma was made on histopathology from either endoscopic or excisional biopsy of the lesion. Demographics, diagnostic imaging, histopathologic characteristics, and outcomes were analyzed. RESULTS: We identified 48 patients, of whom 29 (60%) were female, >18 y (38; 79%), with a mean age of 43 y at the time of diagnosis (range, 4 d-87 y). Tumors ranged in size from <1 cm to 30 cm. Only 1/3 were symptomatic, most commonly with abdominal pain (9; 19%) On preoperative imaging, mural nodules or thickened walls were present in one case, in which pathology was consistent with benign lymphangioma. The majority of lymphangiomas were associated with the small bowel or its mesentery (31; 65%), followed by the colon/omentum (7; 15%). Most patients underwent surgical excision (29; 60%) with incomplete excision in one patient due to extensive local invasion, and three (10%) patients required multivisceral resection. The median duration of the follow-up was 13 mo (range, 1-105 mo), during which time, none of the patients developed malignancy. CONCLUSIONS: Most abdominal lymphangiomas arise from the small bowel and are found incidentally and have a favorable prognosis. Resection should be reserved for symptomatic lesions or when there is a diagnostic uncertainty.
