Tae Won Kwon

Experience of an abdominal aortic aneurysm in a patient having crossed ectopia with fusion anomaly of the kidney.

We report a case of surgically treated abdominal aortic aneurysm (AAA) in a patient having crossed ectopia with fusion anomaly of the kidney. One artery from the abdominal aorta above the aneurysm supplies the right kidney while three renal arteries (two from the aneurysm itself and one from the left common iliac artery) supply the crossed ectopic kidney. Preoperative imaging to define the arterial and collecting systems along with a detailed planning of the operation is essential to prevent ischemic renal injury as well as ureteral injury during AAA repair.

A Retrospective 10-Year, Single-Institution Study of Carotid Endarterectomy with a Focus on Elderly Patients

Background and Purpose This study evaluated the outcome following surgery for carotid artery stenosis in a single institution during a 10-year period and the relevance of aging to access to surgery. Methods Between January 2001 and December 2010, 649 carotid endarterectomies (CEAs) were performed in 596 patients for internal carotid artery occlusive disease at our institution; 596 patients received unilateral CEAs and 53 patients received bilateral CEAs. Data regarding patient characteristics, comorbidities, stroke, mortality, restenosis, and other surgical complications were obtained from a review of medical records. Since elderly and high-risk patients comprise a significant proportion of the patient group undergoing CEAs, differences in comorbidity and mortality were evaluated according to age when the patients were divided into three age groups: <70 years, 70-79 years, and ≥80 years. Results The mean age of the included patients was 67.5 years, and 88% were men. Symptomatic carotid stenosis was observed in 65.7% of patients. The rate of perioperative stroke and death (within 30 days of the procedure) was 1.84%. The overall mortality rate was higher among patients in the 70-79 years and >80 years age groups than among those in the <70 years age group, but there was no significant difference in stroke-related mortality among these three groups. Conclusions CEA over a 10-year period has yielded acceptable outcomes in terms of stroke and mortality. Therefore, since CEA is a safe and effective strategy, it can be performed in elderly patients with acceptable life expectancy.

Abdominal aortic aneurysm in giant cell arteritis

Aortic complications of giant cell arteritis are a rare cause of abdominal aortic aneurysm. Here, we describe a case of a ruptured aortic aneurysm in a patient with giant call arteritis (GCA) who was preoperatively suspected of having an infectious aortic aneurysm. Intraoperative inspection revealed infectious granulation tissue on the anterior wall of the abdominal aorta. GCA was finally confirmed by pathological diagnosis. Our findings suggest that the surgical and postoperative treatment of nonatheromatous aortic aneurysm should be based on accurate diagnosis.

Impact of a preoperative evaluation on the outcomes of an arteriovenous fistula

Purpose The aim of this study was to determine the possible predictors of primary arteriovenous fistula (AVF) failure and examine the impact of a preoperative evaluation on AVF outcomes. Methods A total of 539 patients who underwent assessment for a suitable site for AVF creation by physical examination alone or additional duplex ultrasound were included in this study. Demographics, patient characteristics, and AVF outcomes were analyzed retrospectively. Results AVF creation was proposed in 469 patients (87.0%) according to physical examination alone (351 patients) or additional duplex ultrasound (118 patients); a prosthetic arteriovenous graft was initially placed in the remaining 70 patients (13.0%). Although the primary failure rate was significantly higher in patients assessed by duplex ultrasound (P = 0.001), ultrasound information changed the clinical plan, increasing AVF use for dialysis, in 92 of the 188 patients (48.9%) with an insufficient physical examination. Female sex and diabetes mellitus were risk factors significantly associated with primary AVF failure. Because of different inclusion criteria and a lack of adjustment for baseline differences, Kaplan-Meier survival analysis showed better AVF outcomes in patients assessed by physical examination alone; an insufficient physical examination was the only risk factor significantly associated with AVF outcomes. Conclusion Routine use of duplex ultrasound is not necessary in chronic kidney disease patients with a satisfactory physical examination. Given that female gender and diabetes mellitus are significantly associated with primary AVF failure, duplex ultrasound could be of particular benefit in these subtypes of patients without a sufficient physical examination.

Clinical Outcomes of Cryopreserved Arterial Allograft Used as a Vascular Conduit for Hemodialysis

This single center cohort study aimed to test the hypothesis that use of a cryopreserved arterial allograft could avoid the maturation or healing process of a new vascular access and to evaluate the patency of this technique compared with that of vascular access using a prosthetic graft. Between April 2012 and March 2013, 20 patients underwent an upper arm vascular access using a cryopreserved arterial allograft for failed or failing vascular accesses and 53 using a prosthetic graft were included in this study. The mean duration of catheter dependence, calculated as the time interval from upper arm access placement to removal of the tunneled central catheter after successful cannulation of the access, was significantly longer for accesses using a prosthetic graft than a cryopreserved arterial allograft (34.4 ± 11.39 days vs. 4.9 ± 8.5 days, P < 0.001). In the allograft group, use of vascular access started within 7 days in 16 patients (80%), as soon as from the day of surgery in 10 patients. Primary (unassisted; P = 0.314) and cumulative (assisted; P = 0.673) access survivals were similar in the two groups. There were no postoperative complications related to the use of a cryopreserved iliac arterial allograft except for one patient who experienced wound hematoma. In conclusion, upper arm vascular access using a cryopreserved arterial allograft may permit immediate hemodialysis without the maturation or healing process, resulting in access survival comparable to that of an access using a prosthetic graft.

B-mode Ultrasound Imaging in Symptomatic Internal Carotid Artery Stenosis: Correlation with Clinical and Operative Findings

B-mode ultrasound (duplex) imaging is a technique that enables the evaluation of plaque characteristics. The purpose of this study was to determine the accuracy and usefulness of duplex imaging by comparing a relationship between the preoperative clinical neurologic status, preoperative duplex findings, and operative findings in patients who had carotid endarterectomy (CEA) for symptomatic high-grade internal carotid artery (ICA) stenosis. Sixty patients with symptomatic ICA stenosis who underwent CEA from September 1995 to August 1998 were included in this study. Plaque morphology was categorized in terms of echogenicity by preoperative duplex imaging. A correlation between the frequency of preoperative ischemic stroke and duplex and operative findings was prospectively evaluated. Thirty-eight patients had recent and multiple cerebral ischemia, and 22 experienced a single episode more than 1 month before CEA. Recent and multiple events occurred in 24 (72.7%) of 33 patients with echolucent plaques, but only 6 (40.0%) of 15 with echogenic plaques (p<0.05). Thirty-six (75%) of 48 patients with soft plaques by operative findings had recent and multiple events, but only two (16.7%) of 12 with calcified plaques experienced recent and multiple events (p<0.01). Overall sensitivity, specificity, and accuracy of duplex imaging were 79.5%, 77.8%, and 79.2%, respectively. Duplex imaging is reliable in determining ICA plaque characteristics. Recent and multiple cerebral ischemia occurred more frequently in patients with echolucent plaques by preoperative duplex and soft plaques by operative findings. The presence of echolucent plaque may be used as a strong indication for CEA in patients who have asymptomatic high-grade ICA stenosis.

A new risk-scoring model for predicting 30-day mortality after repair of abdominal aortic aneurysms in the era of endovascular procedures

Purpose To propose a new, multivariable risk-scoring model for predicting 30-day mortality in individuals underwent repair of abdominal aortic aneurysms (AAA). Methods Four hundred eighty-five consecutive patients who underwent AAA repair from January 2000 to December 2010 were included in the study. Univariate and multivariate analyses were performed to evaluate the risk factors, and a risk-scoring model was developed. Results Multivariate analysis identified three independent preoperative risk factors associated with mortality, and a risk-scoring model was created by assigning an equal value to each factor. The independent predictors were location of the AAA, rupture of AAA, and preoperative pulmonary dysfunction. The multivariable regression model demonstrated moderate discrimination (c statistic, 0.811) and calibration (Hosmer-Lemeshow test, P = 0.793). The observed mortality rate did not differ significantly from that predicted by our risk-scoring model. Conclusion Our risk-scoring model has excellent ability to predict 30-day mortality after AAA repair, and awaits validation in further studies.

Clinical outcome of early relaparotomy after elective open repair of abdominal aortic aneurysms

Purpose The aim of this study was to retrospectively evaluate the association of need for early relaparotomy with clinical outcomes after elective open repair of abdominal aortic aneurysms (AAAs). Methods A total of 292 consecutive patients who underwent elective open AAA repair at Asan Medical Center from January 2001 to December 2010 were included in this study, and we compared the demographics, clinical characteristics, related risk factors, and clinical outcomes of early relaparotomy versus nonrelaparotomy patients. Results The incidence of early relaparotomy during a single hospital stay was 4.1% (n = 12), and the most common causes were bowel ischemia (n = 5, 41.7%) and postoperative bleeding (n = 3, 25.0%). Among the demographics and clinical characteristics significantly associated with relaparotomy were: age (P = 0.025), chronic obstructive pulmonary disease (COPD) (P = 0.010), number of RBC units transfused during the AAA repair (P = 0.022) and in the following week (P = 0.005), and length of intensive care (P < 0.001) and overall hospital stay (P < 0.001). On multivariate analysis, presence of COPD (P = 0.009) and number of RBC units transfused during the AAA repair (P = 0.006) were statistically significantly associated with relaparotomy. Furthermore, early relaparotomy was associated with perioperative (within 30 days) (P = 0.048) and overall in-hospital mortality (P = 0.001). Conclusion Early relaparotomy has an adverse effect on clinical outcomes: increased mortality and hospital length of stay. Presence of COPD and need for RBC transfusion are associated with early relaparotomy.