Identification of fifty-seven novel loci for abdominal wall hernia development and their biological and clinical implications: results from the UK Biobank.

PURPOSE: Familial aggregation is known for both hernia development and recurrence. To date, only one genome-wide association study (GWAS) limited to inguinal hernia has been reported that identified four risk-associated loci. We aim to investigate polygenic architecture of abdominal wall hernia development and recurrence. METHODS: A GWAS was performed in 367,394 subjects from the UK Biobank to investigate the polygenic architecture of abdominal wall hernia subtypes (inguinal, femoral, umbilical, ventral) and identify specific single nucleotide polymorphisms (SNPs) that are associated with their risk. Expression quantitative trait loci (eQTL) analysis was performed to identify genes whose expression levels are associated with these SNPs. A genetic risk score (GRS) was used to assess the cumulative effect of multiple independent risk-associated SNPs on hernia development and recurrence in independent subjects (n = 82,064). RESULTS: Heritability (h2) was 0.12, 0.06, 0.16, and 0.07 for inguinal, femoral, umbilical, and ventral hernias, respectively. A high-level of genetic correlation (rg) was found among these subtypes of hernia. We confirmed the aforementioned four loci and identified 57 novel loci (P < 5 × 10-8), including 55, 3, 5, and 3 loci for inguinal, femoral, umbilical, and ventral hernias, respectively. Significantly different expression levels between risk/reference alleles of SNPs were found for 145 genes, including TGF-ß2 and AIG1 for inguinal hernia risk and CALD1 for umbilical hernia risk. Finally, higher GRS deciles were significantly associated with increased risk for hernia development (Ptrend = 3.33 × 10-38) and recurrent hernia repair surgery (Ptrend = 3.64 × 10-14). CONCLUSION: These novel results have potential biological and clinical implications for hernia management in high-risk patients.

Rectus abdominis atrophy after ventral abdominal incisions: midline versus chevron.

PURPOSE: Although many outcomes have been compared between a midline and chevron incision, this is the first study to examine rectus abdominis atrophy after these two types of incisions. METHODS: Patients undergoing open pancreaticobiliary surgery between 2007 and 2011 at our single institution were included in this study. Rectus abdominis muscle thickness was measured on both preoperative and follow-up computed tomography (CT) scans to calculate percent atrophy of the muscle after surgery. RESULTS: At average follow-up of 24.5 and 19.0 months, respectively, rectus abdominis atrophy was 18.9% greater in the chevron (n = 30) than in the midline (n = 180) group (21.8 vs. 2.9%, p < 0.0001). Half the patients with a chevron incision had >20% atrophy at follow-up compared with 10% with a midline incision [odds ratio (OR) 9.0, p < 0.0001]. No significant difference was observed in incisional hernia rates or wound infections between groups. CONCLUSION: In this study, chevron incisions resulted in seven times more atrophy of the rectus abdominis compared with midline incisions. The long-term effects of transecting the rectus abdominis and disrupting its innervation creates challenging abdominal wall pathology. Atrophy of the abdominal wall can not be readily fixed with an operation, and this significant side effect of a transverse incision should be factored into the surgeon's decision-making process when choosing a transverse over a midline incision.

Should pulmonary lesions be resected at the time of open heart surgery?

The prevalence and malignant potential of pulmonary lesions found preoperatively in patients undergoing coronary artery bypass grafting (CABG) surgery are poorly defined. In a review of 3364 consecutive patients undergoing CABG, 191 (5%) were found to have pulmonary lesions. Granulomatous disease was suspected in all patients who had only calcified lesions (n = 151). These were empirically observed with no changes seen at follow-up. The 40 patients with noncalcified lesions (NCLs) were managed variously. Twenty patients underwent resection of the suspicious pulmonary lesion at the time of cardiac surgery. One patient underwent wedge resection of a pulmonary lesion (benign granuloma) 4 days before CABG. Eighteen patients underwent concomitant pulmonary resection and CABG through the median sternotomy (7 benign, 11 malignant). A delayed pneumonectomy was performed 17 days after CABG in another patient. Three of 40 patients died during the perioperative period without pathologic diagnosis. The remaining 17 were followed with serial roentgenograms. Three of 17 (18%) had lesional enlargement in the follow-up period their lesions were found to be malignant. The remaining 14 patients have been observed without surgical intervention now with a mean follow-up of 5.7 years (range, 20 months to 13 years). The prevalence of malignancy in lesions found on CABG preoperative chest roentgenograms was 15 out of 191 (7.8%); however, among patients with NCL the prevalence of malignancy was 15 out of 40 (37%), and malignancy was present in 12/13 (92%) of patients with NCLs that were >/= 2 cm in diameter. When malignancy is diagnosed in an NCL before CABG surgery, the decision to proceed with CABG should be based upon the coronary pathophysiology and the stage and cell type of the malignancy. Concomitant CABG and pulmonary resection is possible in most cases; however, we prefer a staged resection of all newly diagnosed NCLs when these are identified in patients requiring emergent revascularization or when these lesions are difficult to access through sternotomy. The mortality rate may be slightly increased in patients having concomitant procedures (5.47%) versus isolated CABG (3%). The incidence of malignancy in these NCLs is related to size. If a staged resection is not undertaken after CABG, careful observation of NCLs is important, as 18 per cent of these so managed were ultimately found to be malignant.

Lack of cardioplegia uniformity in clinical myocardial preservation.

Advances in myocardial preservation have led to improved patient survival after open heart operations. However, few studies have detailed the nature of national or regional patterns of cardioplegia use. To determine the regional pattern, all open heart surgery programs in Missouri were surveyed. During 1 year, it was found that cardioplegia was administered to 8,382 patients by 61 cardiothoracic surgeons at ten academic affiliated hospitals and 16 nonteaching hospitals. All cardioplegic solutions were hospital produced. Of 13 crystalloid solutions, 11 differed from one another and eight were intracellular formulations. Of 28 multidose blood-based cardioplegic solutions, there were 23 different mixtures. Most crystalloid (69%) and blood-based (89%) solutions differed substantially from commonly reported formulations. The incidences of the various additives to crystalloid solutions were as follows: bicarbonate, 92%; glucose, 69%; lidocaine, 54%; mannitol, 46%; magnesium, 31%; calcium, 23%; methylprednisolone, 15%; heparin, 8%; and acetate, 8%. Of the common blood-based cardioplegic solution additives, the following incidences were observed: glucose, 79%; bicarbonate, 43%; trishydroxyaminomethane, 36%; acetate, 29%; magnesium, 29%; procaine (or lidocaine), 25%; citrate-phosphate-dextrose, 18%; mannitol/albumin, 14%; nitroglycerin, 11%; glutamate/aspartate, 11%; calcium, 7%; insulin, 3%; and methylprednisolone, 3%. No calcium channel blocker or high-energy phosphate additives were reported. We conclude that many different cardioplegic admixtures that have not been tested experimentally are used routinely in clinical practice, presumably with acceptable results. Because the salutary effects of induced cardiac arrest and hypothermia may mask suboptimal solutions, further study of customized cardioplegia should be considered, particularly with regard to high-risk patients.