A Comparative analysis of PESC and PPSC copolyesters: Insights into viscosity, thermal behavior, crystallinity, and biodegradability.

The study examined various properties of synthesized copolyesters PESC and PPSC. Inherent viscosities of the copolyesters, measured in 1,4-dioxane at 32 °C, were 0.65 dL/g for PESC and 0.73 dL/g for PPSC. Fourier-Transform Infrared Spectroscopy (FT-IR) revealed distinct absorption bands associated with ester carbonyl stretching, C-H bending vibration, C-H group symmetry stretching, and C-O stretching vibrations. 1H and 13C Nuclear magnetic Resonance (NMR) spectroscopy were used to identify specific protons and carbon groups in the polymer chain, revealing the molecular structure of the copolyesters. Differential Scanning Calorimetry (DSC) identified the glass transition, melting, and decomposition temperatures for both copolyesters, indicating variations in the crystalline nature of the copolymers. XRD Spectral studies further elaborated on the crystalline nature, indicating that PPSC is less amorphous than PESC. Biodegradation analysis showed that PESC degrades more quickly than PPSC, with degradation decreasing as the number of methylene groups increase. Scanning Electron Microscopy (SEM) images depicted the surface morphology of the copolyesters before and after degradation, revealing a more roughened surface with pits post-degradation. These findings provide comprehensive insights into the structural and degradable properties of PESC and PPSC copolyesters.

Right Living Donor Nephrectomies: Retroperitoneoscopic vs Laparoscopic Transperitoneal Approach.

Retroperitoneoscopic right living donor nephrectomy (RLDN) provides direct access to the renal hilum without the need to mobilize the colon. However, factors such as lack of anatomic landmarks to guide orientation, smaller working space, and steep learning curve provided a debate against this approach. In this retrospective study, we reviewed our single-center experience of retroperitoneoscopic RLDN. MATERIALS AND METHODS: Between January 2015 and January 2017, 10 patients underwent retroperitoneoscopic RLDN by a single surgeon at the National University Hospital, Singapore. Baseline demographics, intraoperative parameters, and both donor and recipient outcomes were retrieved from the database. RESULTS: Mean (SD) age was 52.7 (13.8) years, mean (SD) body mass index was 25.2 (2.9) kg/m2, mean (SD) operating time was 196.8 (38.0) minutes, mean (SD) warm ischemic time was 5.1 (2.1) minutes, and mean (SD) blood loss was 43 (25.0) mL. Mean (SD) renal vein length was 10 (2.5) mm, and mean (SD) renal artery length was 6 (1.8 mm). One patient had to be converted to laparoscopic transperitoneal nephrectomy. No donors developed complications. Mean (SD) hospital stay was 3.5 (1.1) days. All transplanted right kidneys had immediate graft function with no complications. Mean (SD) serum creatinine (at 1 year) was 103.6 (20.3) µmol/L. There is no graft loss among the recipient after 1 year. CONCLUSIONS: Right donor nephrectomy can be performed safely using retroperitoneoscopic approach. Retroperitoneoscopy offers advantages, especially in a patient who previously had transabdominal surgery or high body mass index. However, transperitoneal approach may be preferable in anomalous situations because it provides instinctive orientation from anatomic landmarks and a greater working space.

Renal Artery Diameter Is a Surrogate Marker for Kidney Volume in Living Kidney Donors.

Donor kidney volume (KV) is an increasingly important parameter evaluated before living kidney donation; however, KV measurements on computed tomographic (CT) scanning requires a manually intensive process of manual or semiautomatic segmentation of kidneys with interobserver variation. Renal artery diameter (RAD) is an easier marker to measure, and this study aims to investigate the relationship between donor RAD and KV. METHODS: A retrospective review of 77 patients who underwent living donor nephrectomy was conducted. Bilateral KVs were measured based on contrast-enhanced CT scan imaging, and renal artery maximum diameter was measured by direct visualization on the arterial phase of transverse CT sections. RESULTS: On regression analysis, there was a significant association between the right and left RADs and their ipsilateral KVs with a regression coefficient of 7.9 (95% CI, 1.3-14.5; P = .02) and 9.8 (95% CI, 3.3-16.3; P = .004), respectively. Mean total RAD correlated with total KV with a regression coefficient of 9.3 (95% CI, 3.8-14.7; P = .001) and weakly correlated with estimated glomerular filtration rate with a Pearson coefficient of .10. CONCLUSIONS: This study demonstrates that renal artery size is positively associated with KV and may be used as an easily measured surrogate marker for kidney size with its attended implications in living donor transplantation.