Sun Cheol Park

Pre-existing Arterial Micro-Calcification Predicts Primary Unassisted Arteriovenous Fistula Failure in Incident Hemodialysis Patients.

Vascular access micro‐calcification is a risk factor for cardiovascular morbidity and mortality in hemodialysis (HD) patients but its influence on vascular access patency is still undetermined. Our study aimed to determine the impact of arterial micro‐calcification (AMiC) on the patency of vascular access in HD patients. One‐hundred fourteen HD patients receiving arteriovenous fistula (AVF) operation were included in this study. During the operation, we obtained partial arterial specimen and performed pathological examination by von Kossa stain to identify AMiC. We compared primary unassisted AVF failure within 1 year between positive and negative AMiC groups, and performed Cox regression analysis for evaluating risk factor of AVF failure. The incidence of AMiC was 37.7% and AVF failure occurred in 45 patients (39.5%). The AVF failure rate within 1 year was greater in the positive AMiC group than those in the negative AMiC group (53.5% vs. 31.0%, p = 0.02). Kaplan–Meier analysis showed that the positive AMiC group had a lower AVF patency rate than the negative AMiC group (p = 0.02). The presence of AMiC was an independent risk factor for AVF failure. In conclusion, preexisting AMiC of the vascular access is associated with primary unassisted AVF failure in incident HD patients.

Arterial Micro-Calcification of Vascular Access is Associated with Aortic Arch Calcification and Arterial Stiffness in Hemodialysis Patients

Vascular calcification of the coronary arteries or aorta is an independent risk factor for cardiovascular outcome, but clinical significance of arterial micro‐calcification (AMC) of vascular access is unclear in hemodialysis (HD) patients. Sixty‐five patients awaiting vascular access operation were enrolled. We compared surrogate markers of cardiovascular morbidity such as aortic arch calcification (AoAC) by chest radiography, arterial stiffness by brachial‐ankle pulse wave velocity (baPWV) and endothelial dysfunction by flow‐mediated dilatation (FMD) between patients with and without AMC of vascular access on von Kossa staining. AMC of vascular access was detected in 36 (55.4%). The AMC‐positive group had significantly higher incidence of AoAC (63.9% vs. 20.7%, p < 0.001) and higher baPWV (26.5 ± 9.4 m/s vs. 19.8 ± 6.6 m/s, p = 0.006) than the AMC‐negative group. There was no significant difference in FMD between the two groups (5.4 ± 2.6% vs. 5.7 ± 3.5%, p = 0.764). The AMC‐positive group had higher incidence of diabetes mellitus, higher systolic blood pressure and wider pulse pressure than the AMC‐negative group. This study suggests that AMC of vascular access may be associated with cardiovascular morbidity via AoAC and arterial stiffness in HD patients.

Endovascular treatment of a spontaneous aneurysm in the axillary artery

Spontaneous aneurysm in the axillary artery is extremely rare. The standard treatment for axillary artery aneurysm has been surgical repair, but endovascular management of select aneurysms using stent grafts has become more prevalent with the development of endoluminal technology. We report the case of a 36-year old man with a spontaneous aneurysm in the axillary artery. He experienced a tingling sensation and intermittent pain in the left upper extremity and had no history of trauma to the axilla. We performed endovascular treatment [placement of a Viabahn stent graft (W.L. Gore & Associates, Flagstaff, AZ, USA)] for a spontaneous aneurysm in the axillary artery. Following the procedure, his symptoms disappeared completely. After 6, 12 and 24 months, we carried out computed tomography angiography; all scans showed no complications. Now, the patient has no symptoms related to aneurysm in the axilla.

Predictors of Postoperative Mortality of Ruptured Abdominal Aortic Aneurysm: A Retrospective Clinical Study

Purpose Despite significant improvements in surgery, anesthesia, and postoperative critical care, the postoperative mortality rate of ruptured abdominal aortic aneurysm (RAAA) has remained at 40% to 50% for several decades. Therefore, we evaluated factors associated with the postoperative mortality of RAAA. Materials and Methods From January 1999 to December 2008, a retrospective study was performed with 34 patients who underwent open repair of RAAA. The preoperative factors included age, sex, smoking, comorbidities, serum creatinine, hemoglobin, shock, pulse rate, and time from emergency room to operation room. The intraoperative factors included blood loss, transfusion, aortic clamping site and time, aneurysmal characteristics, rupture type, graft type, hourly urine output (HUO), and operative time. The postoperative factors included inotropic support, renal replacement therapy (RRT), reoperation, bowel ischemia, multiple organ failure (MOF), and intensive care unit stay. The 2-day and the 30-day mortality rates were analyzed separately. Results The 2-day and the 30-day mortality rates were 14.7% and 41.2%, respectively. On univariate analysis, shock, transfusion, HUO, inotropic support and MOF for the 2-day mortality and serum creatinine, transfusion, aortic clamping site, HUO, inotropic support, RRT and MOF for the 30-day mortality were statistically significant. On multivariate analysis, shock, inotropic support and MOF for the 2-day mortality and aortic clamping site, RRT and MOF for the 30-day mortality were statistically significant. Conclusion To decrease the postoperative mortality rate of RAAA, prevention of massive hemorrhage and acute renal failure with infrarenal aortic clamping, as well as prompt operative control of bleeding and maintenance of systemic perfusion are important.

Spontaneous fracture and migration of catheter of a totally implantable venous access port via internal jugular vein--a case report.

BackgroundThe totally implantable venous access ports (TIVAPs) are indicated for patients undergoing chemotherapy, total parenteral nutrition and long-term antibiotic treatment. But, among their complications, the fracture and migration of the catheter of a TIVAP via internal jugular vein represents a very rare but potentially severe condition.Case presentationA 50-year-old woman indentified with a spontaneous fracture and migration of catheter of a TIVAP via right internal jugular vein after adjuvant chemotherapy for ovary cancer. She had been not evaluated and not managed with the heparin lock flush solution during three months after adjuvant chemotherapy. And then, she complained right neck bulging during saline infusion via a TIVAP and a chest radiography showed the fractured and migrated catheter of a TIVAP in right atrium. So, we emergently removed the catheter fragment by a goose neck snare via right femoral vein. After then, there was no problem.ConclusionsIf the fractured catheter of a TIVAP is detected, it is desirable to remove a fragment by an endovascular approach if it is possible.

Different Effects of Orbital Shear Stress on Vascular Endothelial Cells: Comparison with the Results of In Vivo Study with Rats

Purpose: An attempt was made to characterize the orbital shear stress by comparing the effects of orbital shear stress on vascular endothelial cells (ECs) with the results of animal experiments. Materials and Methods: In the laboratory study, cultured ECs of well were distinguished by center and periphery then exposed to orbital shear stress using an orbital shaker. In the animal study, arteriovenous (AV) fistulas were made at the right femoral arteries of Sprague-Dawley rats to increase the effect of the laminar flow. The condition of the stenosis was given on the left femoral arteries. The protein expression of inducible nitric oxide synthase (iNOS) and Akt phosphorylation were observed and compared. Results: Under orbital shear stress, ECs showed an increase in iNOS protein expression and phosphorylation of Akt but most of the protein expressions derived from the periphery. When compared to the animal study, the increased expression of iNOS protein and phosphorylation of Akt were observed in the sample of AV fistula conditions and the iNOS protein expression was decreased in the stenosis conditions. Conclusion: Orbital shear stress did not show the characteristics of a pure turbulent shear force. By comparing the observation with the morphological changes of vascular ECs and site-specific protein expression on the results of animal experiments, uniform directional lamina shear stress forces were expressed at the periphery.

Clinical significance of C4d deposition in stable renal allografts in the early post-transplantation period

Abstract:  The clinical significance of C4d positivity in patients with stable graft function is undetermined. This study evaluated the clinical outcome of protocol biopsy‐proven C4d‐positive renal transplants with stable graft function in the early post‐transplantation period. Protocol biopsies (n = 79) were performed on stable allografts on the 14th post‐transplant day, and indication biopsies (n = 74) were performed on dysfunctioning allografts within one yr after transplantation. Clinical and histological findings, graft function and graft survival rates were compared between C4d‐positive and C4d‐negative grafts in each group. The incidence of C4d positivity was 5.1% in protocol biopsies and 9.5% in indication biopsies. In protocol biopsies, C4d‐positive allografts showed minimal tubulointerstitial inflammation, and the graft function and graft survival rate did not differ from C4d‐negative allografts. All C4d‐positive allografts maintained stable graft function without anti‐rejection therapy, and follow‐up biopsies of two patients showed no C4d deposition or evidence of rejection. On the other hand, C4d‐positive allografts in indication biopsies showed severe tissue injury, and the graft survival rate was significantly lower than C4d‐negative allografts. In conclusion, C4d‐positive allografts with stable graft function in the early post‐transplantation period take an indolent course.

Risk factors and long-term outcomes of delayed graft function in deceased donor renal transplantation

Purpose The purpose of this study was to analyze the risk factors for delayed graft function (DGF) and determine its impact on the outcomes of deceased donor (DD) kidney transplantation (KT). Methods Between January 2000 and December 2011, we performed 195 DD renal transplants. After the exclusion of primary nonfunctional grafts (n = 4), the study recipients were divided into two groups-group I, DGF (n = 31, 16.2%); group II, non-DGF (n = 160, 83.8%). The following variables were compared: donor and recipient characteristics, patient and graft survival, postoperative renal function, acute rejection (AR) episodes, and the rates of surgical and infectious complications. Results Donor-related variables that showed significant differences included hypertension (P = 0.042), diabetes (P = 0.025), and prerecovery serum creatinine levels (P < 0.001). However, there were no significant differences in recipient-related factors. One significantly different transplant-related factor was positive panel reactive antibody (PRA > 20%, P = 0.008). On multivariate analysis, only the prerecovery serum creatinine level (P < 0.001; hazard ratio [HR], 1.814) was an independent risk factor for the development of DGF. A Cox multivariate analysis of risk factors for graft survival identified these independent risk factors for graft survival: nephron mass (donor kidney weight to recipient body weight ratio) index (P = 0.026; HR, 2.328), CMV infection (P = 0.038; HR, 0.114), and AR episode (P = 0.038; HR, 0.166). Conclusion In DD KT, an independent risk factor for DGF was the prerecovery serum creatinine level. Although there was a significant difference in graft survival between the DGF and non-DGF groups, DGF was not an independent risk factor for graft failure in this study.

Balloon-assisted maturation for arteriovenous fistula maturation failure: an early period experience

Purpose Balloon-assisted maturation (BAM) is emerging as a salvage management for arteriovenous fistula maturation failure (AVF MF). However, BAM is a relatively new, yet controversial technique for AVF maturation. Therefore, we evaluated the effectiveness of BAM for AVF MF. Methods Between January 2012 and December 2014, 249 AVFs were created. The total MF rate was 24.8%. But, only 110 AVFs were enrolled, including 74 brachiocephalic (BC) AVFs and 36 radiocephalic (RC) AVFs. The follow-up period was 12 months. Among those, there were 42 MFs (22 BC AVFs and 20 RC AVFs) and 68 maturation successes (MS) (52 BC AVFs and 16 RC AVFs). BAM was involved in MF group. We compared the clinical characteristics, AVF flows, and AVF flow ratios of MF and MS groups. Also, we evaluated the etiology, management, and result of MF. Results There was no difference in clinical characteristics between MF and MS groups. In MF group, 39 balloon angioplasties (BAs) for 42 AVF MFs were performed. Number of BA was 1.45 ± 0.57 and duration of BA was 21.30 ± 21.24 weeks. BAM rate was 46.2%. For 1 year after AVF creation, AVF flows of MS group were significantly larger than those of MF group (P < 0.05) but there was no difference in AVF flow ratio between MF and MS groups (P > 0.05). Conclusion BA for AVF MF is a relatively applicable and effective modality. Although a large volume study is necessary, we suggest BAM is an effective salvage management for AVF MF.

Kidney Transplantation from Living Donor Allograft with Small Renal Cell Cancer after Laparoscopic Partial Nephrectomy: A Case Report

Purpose The allograft shortage extended the limit of traditional criteria used for transplantation. Also to meet the eligible immunologic living donor, it seems suitable to use kidneys with a small renal cancer excised for transplant under the circumstance of scarce deceased donors. Possible risk for malignancy recurrences is still a controversial issue, though kidneys with satisfactory function can be transplanted as far as the recipients comprehend the benefits. The aim of this article is to present a case of living-donor transplantation following laparoscopic partial nephrectomy of small renal cell cancer. Methods A 48-year-old woman recipient with end-stage renal disease was carried on hemodialysis for more than 13 years. Her brother aged 42 was verified with small renal cell cancer (0.7cm) after donor preoperative renal CT scan was done. However, the donor’s renal function was excellent for renal transplantation and showed optimal HLA cross matching result, in contrast with recipients’ other relatives. The recipient and her family consented to have transplantation in a fully informed situation about the possible risk of post-transplant cancer recurrence. Results The graft partial nephrectomy was performed successfully via laparoscopic procedure without renal artery and vein clamping and then laparoscopic donor nephrectomy was carried out. Tumor mass was sent for pathologic analysis and verified normal margin before transplantation. Dual renal arteries were seen and anastomosed to the right external iliac artery end-to-side manner. After the operation, both donor and recipient are physically healthy and the creatinine level (range: 1.05-1.24) of recipient is stable and normal. Recipient is receiving maintenance immunosuppressant following our regimen and no other complications were noted. Conclusion To best of our acknowledgement, this was the first practice of laparoscopic in vivo partial nephrectomy before kidney transplantation. It would be beneficial to proceed with donor partial nephrectomy of renal cell cancer before kidney transplantation in the presence of wide disparity between donor and recipient, and for the best, long term follow-up is essential. Figure. No caption available. Figure. No caption available. Figure. No caption available.