L-Citrulline is a non-essential but still important amino acid that is released from enterocytes. Because plasma levels are reduced in case of impaired intestinal function, it has become a biomarker to monitor intestinal integrity. Moreover, oxidative stress induces protein citrullination, and antibodies against anti-citrullinated proteins are useful to monitor rheumatoid diseases. Citrullinated histones, however, may even predict a worse outcome in cancer patients. Supplementation of citrulline is better tolerated compared to arginine and might be useful to slightly improve muscle strength or protein balance. The following article shall provide an overview of L-citrulline properties and functions, as well as the current evidence for its use as a biomarker or as a therapeutic supplement.

Background and objective: No current nationwide consensus exists on pilonidal disease (PD) treatment in Switzerland and Austria. The objective of this study was to assess and compare the spectrum of PD treatment strategies in Switzerland and Austria. Materials and Methods: A survey including 196 certified institutions (Switzerland, N = 99 and Austria, N = 97) was performed. Treatment strategies for both chronic and acute pilonidal disease were investigated, as well as evolution of treatment over the last 20 years. Results: In total, 92 of 196 (47%) hospitals participated in the survey. Recurrence rate (20%) was similar between the two countries. In acute pilonidal disease, a two-stage approach with incision and drainage as the first step was preferred over a one-stage procedure in both countries. In Austria, all patients with chronic pilonidal disease were treated as inpatients, whereas 28% of patients in Switzerland were treated on an outpatient basis (p = 0.0019). Median length of hospital stay was double in Austria (four days) compared to Switzerland (two days; p < 0.001). Primary resection and off-midline closure (p = 0.017) and the use of tissue flaps (p = 0.023) were performed more commonly in Austria than in Switzerland. Minimally invasive techniques were performed more often in Switzerland than in Austria (52% vs. 4%, p < 0.001). Overall, wide excision with secondary wound healing or midline closures declined over the last 20 years. Conclusion: Treatment strategies for chronic PD differ between Austria and Switzerland with more and longer inpatient care in Austria, increasingly minimally invasive approaches in Switzerland, and outdated procedures still being performed in both countries. Overall, heterogeneity of practice dominates in both countries.

Background—: Appropriate valve sizing is critical in aortic valve replacement. We hypothesized that direct intraoperative valve sizing results in smaller aortic annular diameters compared with sizing based on systolic-phase multidetector computerized tomographic (MDCT) imaging. Methods and Results—: We retrospectively analyzed 78 patients undergoing surgical aortic valve replacement for severe aortic stenosis between 2012 and 2014 at our institution. Preoperative MDCT measurements of the aortic annulus served as basis for assignment to a theoretical surgical valve size, which was then (1) compared to the implanted valve size and (2) to a theoretical transcatheter aortic valve replacement valve size. To quantify the resulting differences, geometric orifice areas (GOA) were calculated. MDCT-based sizing produced the same valve size for n=34 patients (group CT-same), a larger valve with a 25% increased GOA in n=32 patients (group CT-Lg) and a smaller GOA by 22% in n=12 patients (group CT-Sm). On the basis of MDCT measurements, 41% of valves implanted were undersized. The comparison of intraoperative implanted to a theoretical transcatheter aortic valve replacement valve size resulted in GOAs 25% larger for patients in group CT-same, 40.6% larger in group CT-Lg and 14.6% larger in group CT-Sm. Conclusions—: Preoperative MDCT measurements differ substantially from direct intraoperative assessment of the aortic annulus. Implanted surgical aortic valve replacement valves were smaller relative to MDCT-based sizing in 41% of patients, and the potential GOA was between 25% and 40.6% larger if patients had undergone transcatheter aortic valve replacement.

Chronic kidney disease (CKD) is prevalent in patients undergoing aortic valve replacement (AVR). We sought to evaluate the impact of AVR on estimated glomerular filtration rate (eGFR) levels and determine the impact of reversibility of CKD on postoperative outcomes. We retrospectively reviewed 2169 patients who underwent isolated AVR between 2000 and 2012. eGFR was calculated using the CKD-EPI formula. Based on preoperative eGFR, patients were divided into three groups: NoCKD (eGFR >60, n = 1417), ModCKD (eGFR = 30–60, n = 619) and SevCKD (eGFR = 15–30, n = 86). End-stage renal disease patients (eGFR <15 and/or dialysis, n = 47) were excluded from the study. Before AVR, eGFR in the NoCKD, ModCKD and SevCKD groups was 81.3 ± 14.2, 48.9 ± 8.10 and 25.3 ± 4.12 ml/min/1.73 m², respectively. NoCKD patients showed a decline in eGFR during the first month postoperatively; thereafter, eGFR remained stable over 1 year. ModCKD and SevCKD patients demonstrated an initial improvement in eGFR, which peaked at 1 week postoperatively. In ModCKD, eGFR stabilized at a slightly lower level thereafter out to 1-year follow-up. In SevCKD, eGFR declined slightly out to 6 months postoperatively. Regardlessly, eGFR in ModCKD at 1 year and in SevCKD at 6 months postoperatively demonstrated sustained improvement over baseline eGFR. Reversibility of CKD was associated with a better long-term survival in the ModCKD group (P < 0.001) and short-term survival in the SevCKD group (P = 0.018). AVR confers a marked initial improvement in eGFR, which is sustained in patients with ModCKD and SevCKD, and is associated with a better survival. The reversible nature of CKD in certain patients warrants careful consideration during preoperative risk scoring and stratification.