Deniz Balci

Donor Safety and Remnant Liver Volume in Living Donor Liver Transplantation

Living donor liver transplantation is now a common practice in countries in which the availability of cadaveric organs is limited. The preoperative preparation, intraoperative surgical technique, and postoperative care of donors and recipients have evolved in recent years. We retrospectively compared 67 donors with a remnant liver volume equal to or more than 30% (group 1) with 14 donors who had less than 30% remnant liver volume (group 2) for donor outcomes. All the complications in donors were systematically classified. Donors with less than 30% remnant liver volume showed significantly higher peak aspartate aminotransferase, alanine aminotransferase, international normalized ratio, and bilirubin levels. There were 6 complications in group 1 and 4 complications in group 2. The difference between the 2 groups in terms of donor complications did reach statistical significance (P = 0.043); donors with a remnant liver volume < 30% had a 4 times greater relative risk of morbidity. In conclusion, the use of donors with less than 30% remnant liver volume is highly debatable as donor safety should be of utmost importance in living donor liver transplantation. Liver Transpl 14:1174–1179, 2008.

Functional Structure of Adipocytes Differentiated from Human Umbilical Cord Stroma‐Derived Stem Cells

It has been previously demonstrated that human umbilical cord stroma‐derived stem cells (HUCSCs) are competent to differentiate into adipocytes. However, controversies have arisen as to whether HUCSCs can become mature adipocytes or not, and to what extent these cells can be induced in adipogenic pathway. Here, we extensively analyzed their adipogenic potency with a structural and functional approach by determining lipid formation dynamics in concordance to adipocyte‐specific markers. During a 35‐day period, HUCSCs respond to adipogenic induction, at which point 88% of cells exhibited multilocular lipid granules (LGs) having a mean diameter of 3 μm in round‐shaped, F‐actin‐poor cells. Although the 1st week of induction did not generally display typical lipidogenic phenotypes, the degree of adipogenesis was dissected and confirmed by mRNA expressions of peroxisome proliferator‐activated receptor γ, C/EBP‐β, sterol regulatory element‐binding transcription factor 1, adipophilin, stearoyl‐CoA desaturase, glycerol 3‐phosphate dehydrogenase 1, LIPE, adiponectin, and leptin. All markers tested were found elevated in various amounts (3–70‐fold) around day 7 and reached a plateau after day 14 or 21 (5–335‐fold). Perilipin as a surface protein around the LGs was confined exclusively to the enlarging LGs. Conclusively, we propose that after the termination of proliferation, HUCSCs possess the biochemical and cellular machinery to successfully differentiate into maturing adipocytes under adipogenic conditions, and this feature will ultimately allow these fetus‐derived stem cells to be used for various therapeutic or esthetic purposes.

Isolation, culture, and characterization of human umbilical cord stroma-derived mesenchymal stem cells.

As the collection and isolation of human bone marrow-derived mesenchymal stem cells (MSCs) require invasive and often undesirable procurement procedures, investigators have begun to seek alternative sources of human MSC including the umbilical cord stroma. Here we describe the noninvasive isolation, culture, and basic characterization of human umbilical cord stroma-derived mesenchymal stem cells (hUCS-MSCs). Although some technical and observational variations exist between laboratories, there has been a relatively common consensus regarding the immunological and functional characteristics of hUCS-MSCs. Successful in vitro and in vivo differentiation to several lineages makes these cells an invaluable stem cell source, deserving further testing as a cellular therapy or other applications in regenerative medicine. Therefore, the isolation and culture of hUCS-MSCs still need better clarification to ultimately build an optimal standard procedure among laboratories, tissue banks, and clinics.

Brachiobasilic versus brachiocephalic arteriovenous fistula: a prospective randomized study.

BACKGROUND The most recent Kidney Disease Outcomes Quality Initiative (KDOQI) guidelines recommend that the order of preference for arteriovenous fistula (AVF) placement is the radial-cephalic primary AVF, followed by the secondary brachiocephalic (BC) and, if either of these is not viable, then brachiobasilic (BB) AVF should be fashioned. However, there is limited prospective data comparing technical and clinical outcomes of these two approaches. The purpose of our study was to compare outcome, patency, and complication rates in these two autogenous upper arm AV accesses. METHODS Between December 2003 and and January 2007, patients (61 male, 39 female) who have lost more distal AVFs were enrolled in the study. After preoperative duplex mapping, patients with patent both basilic and cephalic veins greater than 3 mm of diameter were randomized into BCAVF and BBAVF groups, each group consisting of 50 patients. All procedures were performed under local anesthesia as one-stage procedures. Follow-up data were prospectively collected. Kaplan-Meier analysis was used to calculate primary and secondary patency rates. Univariate and multivariate Cox-regression analysis was used to find risks for the occurrence of thrombosis. RESULTS Baseline demographics, clinical characteristics, and preoperative history dialysis access were comparable between groups with the exception of the fact that mean caliber of the basilic veins were larger (4.51 +/- 0.93 mm vs 3.90 +/- 0.1 mm; P = .002). The mean duration of operation was significantly shorter in the BC group compared with the BB group (P < .001). There was no significant difference in the thirty day mortality, wound complications, 24 hour thrombosis, postoperative hemorrhage, maturation, and time to maturation between the groups. Mean follow-up was 43.2 +/- 1.8 months. Primary patency at 1 and 3 years of follow-up was 87% and 81% for the BC group and 86% and 73% for the BB group (P = .7) Secondary patency at one and three year follow-up was 87% and 70% for the BC group and 88% and 71% for the BB group, respectively (P = .8). Twenty-eight patients (28%) in the BC (18 patients) and BB (10 patients) group died with a patent fistula during the follow-up period (P = .18). Multivariate analysis revealed that use of dominant arm increased the risk of fistula failure. CONCLUSION We conclude that brachiobasilic and brachiocephalic AVF are equally effective alternatives; however, a longer and demanding operation with BB AVF construction should be considered.

Utilization of elderly donors in living donor liver transplantation: When more is less?†

An accepted definition of donor exclusion criteria has not been established for living donor liver transplantation (LDLT). The use of elderly donors to expand the living donor pool raises ethical concerns about donor safety. The aims of this study were (1) the comparison of the postoperative outcomes of living liver donors by age (≥50 versus <50 years) and (2) the evaluation of the impact of the extent of right hepatectomy on donor outcomes. The study group included 150 donors who underwent donor right hepatectomy between October 2004 and April 2009. Extended criteria surgery (ECS) was defined as right hepatectomy with middle hepatic vein (MHV) harvesting or right hepatectomy resulting in an estimated remnant liver volume (RLV) less than 35%. The primary endpoints were donor outcomes in terms of donor complications graded according to the Clavien classification. Group 1 consisted of donors who were 50 years old or older (n = 28), and group 2 consisted of donors who were less than 50 years old (n = 122). At least 1 ECS criterion was present in 74% of donors: 57% had 1 criterion, and 17% had 2 criteria. None of the donors had grade 4 complications or died. The overall and major complication rates were similar in the 2 donor age groups [28.6% and 14.3% in group 1 and 32% and 8.2% in group 2 for the overall complication rates (P = 0.8) and the major complication rates (P = 0.2), respectively]. However, there was a significant correlation between the rate of major complications and the type of surgery in donors who were 50 years old or older. In LDLT, extending the limits of surgery comes at the price of more complications in elderly donors. Right hepatectomy with MHV harvesting and any procedure causing an RLV less than 35% should be avoided in living liver donors who are 50 years old or older. Liver Transpl 17:548–555, 2011.

Use of middle hepatic vein in right lobe living donor liver transplantation

The harvesting of the middle hepatic vein (MHV) with the right lobe graft for living‐donor liver transplantation allows an optimal venous drainage for the recipient; however, it is an extensive operation for the donor. This is a prospective, nonrandomized study evaluating liver functions and early clinical outcome in donors undergoing right hepatectomy with or without MHV harvesting. From August 2005 to July 2007, a total of 100 donor right hepatectomies were performed with (n = 49) or without (n = 51) the inclusion of the MHV. The decision to take MHV was based on an algorithm that considers various donor and recipient factors. There was no donor mortality in donors in either group. Overall complication rate was higher in MHV (+) donor group, however when remnant liver volume was kept above 30%, complication rates were similar between the groups. The results of this study show that right hepatectomy including the MHV neither affects morbidity nor impairs early liver function in donors when remnant volume is kept above 30%. The decision, therefore, of the extent of right lobe donor hepatectomy should be tailored to the particular conditions considering the graft quality and metabolic demand of the recipient.

Assessment of Quality of Life after Laparoscopic Nissen Fundoplication in Patients with Gastroesophageal Reflux Disease

BackgroundIn this study two different quality of life items are compared, and correlation of patient satisfaction with preoperative and postoperative symptoms after laparoscopic Nissen fundoplication (LNF) for chronic gastroesophageal reflux disease is evaluated.Materials and MethodsBetween December 2002 and December 2004, 60 patients with a diagnosis of chronic gastroesophageal reflux disease scheduled for laparoscopic Nissen fundoplication were recruited prospectively and volunteered to participate in this study. Patients underwent endoscopy, and their disease-specific symptoms were scored on a scale. Quality of life was measured preoperatively and in the first and sixth postoperative months with two questionnaires: Short Form-36 (SF 36) (preoperatively) and the Gastroesophageal Reflux Disease—Health-Related Quality of Life (GERD-HRQL) (postoperatively).ResultsIn more than 90% of the patients, typical symptoms (regurgitation and pyrozis) were controlled postoperatively (p < 0.001). In the first postoperative month, however, dysphagia (early dysphagia) was seen in 46 (76%) patients, whereas in the sixth postoperative month (late dysphagia) its incidence decreased to only 2 (3.3%) patients. Similarly, in the first postoperative month 42 (70%) patients had gas bloating, but the incidence of this symptom decreased to 26 (43.3%) patients by the sixth month (p = 0.01). The quality-of-life measurements obtained from both SF 36 and GERD-HRQL showed that quality of life of the patients improved significantly in the related domain of each item after surgery (p < 0.001).ConclusionsLaparoscopic Nissen fundoplication is an effective operation that controls the typical symptoms and improves the quality of life of patients, but new-onset symptoms affect postoperative well-being. For closer evaluation of the benefits of the operation, we need new questionnaires that comprehensively evaluate the symptom spectrum of GERD both preoperatively and postoperatively.

The assessment of cryopreservation conditions for human umbilical cord stroma-derived mesenchymal stem cells towards a potential use for stem cell banking.

Human umbilical cord stroma-derived mesenchymal stem cells (hUCS-MSCs) are considered as a remarkable and promising stem cell source to be potentially used in cellular therapies. While no graft rejection has been reported in the recipient organism even in xeno-transplantation studies, attenuate tumor cell growth and gene transfers have been experimentally shown. In this study, we have demonstrated a reliable, reproducible and efficient cryopreservation method of hUCS-MSCs resulting in one of the highest cell survival rates reported so far. Conventional, computer-controlled multistep slow freezing (MSSF), and vitrification methods were comparatively tested using cell permeable [dimethylsulfoxide (DMSO), ethylene glycol] and impermeable [trehalose, sucrose, hydroxyethyl starch (HES), human serum albumin] cryoprotectant agents (CPAs). After determining the ice nucleation point for each solution, latent heat evolution was suppressed during freezing, followed by a cooling process to -40°C at 1°C/min or 0.3°C/min. The efficiency of the cryopreservation techniques used was determined by cell viability and proliferation assays, the expression of cell surface markers, cytoskeletal proteins and chromosome alignments. The cell survival rate was found to be highest (87 ± 5%) by MSSF with sucrose (0.1 M) +DMSO (10%) at 1°C/min freezing rate. In this group, no significant difference was noted before and after the cryopreservation in cell morphology, cytokeratin, vimentin, and α-smooth muscle actin profiles and the expressions of CD105, CD90, CD73, CD29 and HLA-DR. Second highest cell survival ratio (85 ± 6%) was obtained in DMSO (10%) alone at 1°C/min freezing rate. Interestingly, poor (18 ± 15%) cell survival rates were obtained after vitrification. Cumulatively, results indicated that MSSF favors the other freezing protocols with an addition of sucrose or DMSO alone depending on the freezing rate used.

Apoptotic Vascular Smooth Muscle Cell Depletion via BCL2 Family of Proteins in Human Ascending Aortic Aneurysm and Dissection

AIMS This study investigates the expression patterns of BCL2 (B-cell CLL/lymphoma2) family of proteins and the extent of vascular smooth muscle cell (VSMC) apoptosis in thoracic aortic aneurysms (TAA), type-A aortic dissections (TAD), and nondilated ascending aortic samples. METHODS Aortic wall specimens were obtained from patients undergoing surgical repair for TAA (n = 24), TAD (n = 20), and normal aortic tissues from organ donors (n = 6). The expression pattern of BCL2, BCL2L1 (BCL2-like1), BAK1 (BCL2-antagonist/killer1), and BAX (BCL2-associated X protein) proteins was investigated by immunohistochemistry. Furthermore, colocalization of alpha smooth muscle actin (ACTA2) and caspase3 (CASP3) in aortic VSMCs was analyzed by double-immunofluorescence staining. Onset of DNA fragmentation was measured by TUNEL assay. RESULTS Apoptotic index was significantly increased in both TAD group (31.3 ± 17.2, P < 0.001) and TAA group (21.1 ± 12.7, P = 0.001) relative to control aortas (2.0 ± 1.2). Anti-CASP3 and ACTA2 double-immunostaining confirmed apoptosis in VSMCs in TAA and TAD groups but not in controls. Proapoptotic BAX expression was significantly elevated in VSMCs of TAA patients, compared with that of controls (OR = 20; P = 0.02; 95% CI, 16-250). In contrast, antiapoptotic BCL2L1 expression was higher in controls compared with that of TAA group (OR = 11.2; P = 0.049; 95% CI, 1.0-123.9). Furthermore, BAX/BCL2 ratio was significantly increased in both TAA (1.2 ± 0.7, P < 0.001) and TAD (0.6 ± 0.4, P = 0.05) groups relative to controls (0.2 ± 0.1, P < 0.001). CONCLUSIONS Apoptotic VSMC depletion in human TAA/TAD is associated with disturbance of the balance between proapoptotic and antiapoptotic members of the BCL2 family proteins, which may have a role in the pathogenesis of vascular remodelling in aortic disease. In light of the future studies, targeting apoptotic pathways in TAA and TAD pathogenesis may provide therapeutic benefits to patients by slowing down the progression and even possibly preventing the TAD.

Living donor liver transplantation for hepatocellular carcinoma: a single center analysis of outcomes and impact of different selection criteria

We examined the outcomes of patients who received living donor liver transplantation (LDLT) for HCC comparing the impact of up‐to‐seven criteria and Asan Criteria (AC) with Milan Criteria (MC). Between July 2004 and July 2009, of 175 consecutive LDLT, there were 45 consecutive patients with HCC. Forty patients who completed 12 months follow‐up were enrolled. In search for the highest number of expansion, we selected AC as the extended criteria. Patients were divided into having tumors within MC, beyond MC within AC and Beyond Criteria (BC) groups. With a median follow‐up of 46 months, overall 1, 3, and 5 years survival was −90%, −81%, and −70%, respectively. In patients within AC, estimated mean survival was 49.8 vs. 40.5 months for BC group (P = 0.2). Disease‐free survival was significantly higher in patients within AC comparing with BC group; 48.0 vs. 38.6 months (P = 0.04). Preoperative AFP level >400 and poor tumor differentiation were factors adversely effecting recipient survival. On multivariate analysis, the presence of poor tumor differentiation (P = 0.018 RR: 2.48) was the only independent predictor of survival. Extension of tumor size and number to AC is feasible, without significantly compromising outcomes; however, the presence of poor tumor differentiation was associated with worse outcomes after LDLT.