Hyunwook Kwon

Metformin increases survival in hormone receptor-positive, HER2-positive breast cancer patients with diabetes

IntroductionMetformin use has recently been observed to decrease both the rate and mortality of breast cancer. Our study was aim to determine whether metformin use is associated with survival in diabetic breast cancer patients by breast cancer subtype and systemic treatment.MethodsData from the Asan Medical Center Breast Cancer Database from 1997 to 2007 were analyzed. The study cohort comprised 6,967 nondiabetic patients, 202 diabetic patients treated with metformin, and 184 diabetic patients that did not receive metformin. Patients who were divided into three groups by diabetes status and metformin use were also divided into four subgroups by hormone receptor and HER2-neu status.ResultsIn Kaplan-Meier analysis, the metformin group had a significantly better overall and cancer specific survival outcome compared with non metformin diabetic group (P <0.005 for both). There was no difference in survival between the nondiabetic and metformin groups. In multivariate analysis, Compared with metformin group, patients who did not receive metformin tended to have a higher risk of metastasis with HR 5.37 (95 % CI, 1.88 to 15.28) and breast cancer death with HR 6.51 (95 % CI, 1.88 to 15.28) on the hormone receptor-positive and HER2-negative breast cancer. The significant survival benefit of metformin observed in diabetic patients who received chemotherapy and endocrine therapy (HR for disease free survival 2.14; 95 % CI 1.14 to 4.04) was not seen in diabetic patients who did not receive these treatments.ConclusionPatients receiving metformin treatment when breast cancer diagnosis show a better prognosis only if they have hormone receptor-positive, HER2-positive tumors. Metformin treatment might provide a survival benefit when added to systemic therapy in diabetic patients.

Clinical Outcomes of Anticoagulation Therapy in Patients With Symptomatic Spontaneous Isolated Dissection of the Superior Mesenteric Artery

AbstractThe aim of this study was to determine the clinical outcomes of long-term anticoagulation therapy in patients with symptomatic spontaneous isolated dissection of the superior mesenteric artery (SIDSMA) and to evaluate whether conservative treatment with anticoagulation therapy is a safe and effective treatment modality for these patients.In this single center, observational cohort study, data from a prospectively recruiting symptomatic SIDSMA registry, including demographics, risk factors of interest, clinical characteristics and outcomes, and initial and follow-up computed tomography angiography (CTA) findings, were analyzed retrospectively.During an 8-year period, a total of 52 consecutive patients who underwent conservative treatment with the use of long-term anticoagulation were included in this study. Clinical symptoms resolved within 11 days in all except 4 patients (7.7%); 3 received endovascular treatment for persistent symptoms and 1 received surgical repair. The mean duration of anticoagulation therapy was 9 (range: 3–60) months. A follow-up CTA showed complete remodeling in 20 (41.7%) patients, and the mean diameter and the incidence of false lumen thrombosis were also decreased significantly. There was no anticoagulation therapy-related mortality or morbidity except 2 (4.2%) minor bleeding complications, and no symptomatic recurrence or aggravation of the dissection occurred during the mean follow-up period of 47.5 (range: 10–97) months.The present study showed that long-term anticoagulation therapy could result in a high rate of complete remodeling during the natural course of symptomatic SIDSMA. Conservative treatment with long-term anticoagulation therapy could be an optimal treatment strategy for symptomatic SIDSMA.

Healthcare use and prescription patterns associated with adult asthma in Korea: analysis of the NHI claims database

National Health Insurance (NHI) claim records could provide valuable data for epidemiological studies of asthma in Korea. The aim of this study is to estimate the prevalence of adult asthma and to investigate asthma‐related healthcare use and prescription patterns in Korea over 5 years.

Validation of the cephalosporin intradermal skin test for predicting immediate hypersensitivity: a prospective study with drug challenge

Cephalosporin is a major offending agent in terms of drug hypersensitivity along with penicillin. Cephalosporin intradermal skin tests (IDTs) have been widely used; however, their validity for predicting immediate hypersensitivity has not been studied. This study aimed to determine the predictive value of cephalosporin intradermal skin testing before administration of the drug.

Impact of graft composition on the systemic inflammatory response after an elective repair of an abdominal aortic aneurysm

Purpose The present study aimed to evaluate the risk factors and the role of graft material in the development of an acute phase systemic inflammatory response, and the clinical outcome in patients who undergo endovascular aneurysm repair (EVAR) or open surgical repair (OSR) of an abdominal aortic aneurysm (AAA). Methods We retrospectively evaluated the risk factors and the role of graft material in an increased risk of developing systemic inflammatory response syndrome (SIRS), and the clinical outcome in patients who underwent EVAR or OSR of an AAA. Results A total of 308 consecutive patients who underwent AAA repair were included; 178 received EVAR and 130 received OSR. There was no significant difference in the incidence of SIRS between EVAR patients and OSR patients. Regardless of treatment modality, SIRS was observed more frequently in patients treated with woven polyester grafts. Postoperative hospitalization was significantly prolonged in patients that experienced SIRS. In multivariate analyses, the initial white blood cell count (P = 0.001) and the use of woven polyester grafts (P = 0.005) were significantly associated with an increased risk of developing SIRS in patients who underwent EVAR. By contrast, the use of woven polyester grafts was the only factor associated with an increased risk of developing SIRS in patients who underwent OSR, although this was not statistically significant (P = 0.052). Conclusion The current study shows that the graft composition plays a primordial role in the development of SIRS, and it leads to prolonged hospitalization in both EVAR and OSR patients.

Comparison of surgical and endovascular salvage procedures for juxta-anastomotic stenosis in autogenous wrist radiocephalic arteriovenous fistula.

BACKGROUND Although dysfunctional radiocephalic arteriovenous fistulas (RCAVFs) are typically treated surgically, the endovascular approach is also considered suitable. The aim of this retrospective study was to compare the cumulative patency rates following surgical and endovascular salvaging of dysfunctional RCAVFs, and to evaluate whether the maturity of vascular access sites at the time of treatment influenced the outcomes. METHODS A total of 60 patients underwent surgical or endovascular salvage treatment for juxta-anastomotic stenosis of autogenous wrist RCAVFs: 35 patients underwent proximal neo-anastomosis and 25 underwent percutaneous transluminal angioplasty (PTA). RESULTS Clinical and anatomical success rates were, respectively, 100% and 97.1% in the surgery group, and 100% and 96.0% in the angioplasty group (P = 0.81). The post-treatment restenosis rate was higher in the angioplasty group (n = 11, 46.0%) than in the surgery group (n = 8, 22.8%), without reaching statistical significance (P = 0.15). In a Kaplan-Meier analysis, the primary and assisted primary patency rates were significantly higher in the surgery group (P = 0.036 and P = 0.026, respectively), but there was no significant difference in secondary patency rates between the groups (P = 0.52). When stratified by RCAVF maturity at the time of treatment, no significant difference was noted in primary patency rates between the treatment groups. After adjusting for other variables, the relative risk of restenosis was significantly higher in the angioplasty group (hazard ratio 2.56; 95% confidence interval 1.02-6.46; P = 0.046). CONCLUSIONS Post-treatment primary and assisted primary patency rates after proximal neo-anastomosis were significantly higher than after PTA, and RCAVF maturity did not influence the outcomes.

Pancreas Transplantation From Living Donors: A Single Center Experience of 20 Cases.

Living donor pancreas transplantation (LDPT) has several advantages over deceased donor pancreas transplantation (DDPT), including better HLA matching, shorter ischemic time, and shorter waiting time. It remains an attractive option for diabetes mellitus (DM) patients with end stage renal disease. We reviewed 20 cases of LDPT performed in Asan Medical Center between October 1992 and March 2015. Six cases (30%) were pancreas transplantation alone (PTA), and the rest (70%) were simultaneous pancreas and kidney transplantation (SPK). Relations of donor and recipient were parents in 7 (35%), siblings in 6 (30%), spouse in 6 (30%), and cousin in 1 (5%). Graft survival in SPK at 1, 3, 5, and 10 years was 91.7%, 83.3%, 83.3%, and 83.3%, respectively, and that in PTA recipients was 50%, 33.3%, 16.7%, and 16.7%, respectively (p = 0.005). Causes of graft failure in SPK were thrombosis (one case), and rejection (one case), whereas those in PTA were noncompliance (two cases), thrombosis (one case), reflux pancreatitis (one case), and chronic rejection (one case). In terms of pancreas exocrine drainage, two grafts (25%) maintained their function in bladder drainage, while all grafts maintained in enteric drainage p < 0.05). Seven (35%) donors experienced minor pancreatic juice leakage and one underwent reoperation due to postoperative hematoma. Most donors maintained normoglycemia and normal renal function. However, two donors developed DM (at 1 and 90 months postdonation), and were treated with oral hypoglycemic agents. Graft survival in PTA recipients was poorer than in SPK due to poor compliance and bladder drainage–related problems. The surgical and metabolic complication rates of donors can be minimized by applying strict donor criteria. Therefore, LDPT with enteric drainage is an acceptable treatment for SPK.

Use of cryopreserved cadaveric arterial allograft as a vascular conduit for peripheral arterial graft infection

Major peripheral arterial graft infection is a potentially devastating complication of vascular surgery, associated with significant mortality and high amputation rates. Autologous saphenous veins are considered optimal arterial conduits for lower extremity revascularization in infected fields, but they are often unavailable or unsuitable in these patients. This study describes two patients with major peripheral graft infection, but without available autologous veins, who underwent graft excision and cryopreserved cadaveric arterial allograft reconstruction. Although long-term graft durability is unclear because of gradual deterioration and degeneration, these findings suggest that cadaveric allografts may be good options for patients with major peripheral graft infection.

Analysis of 4000 kidney transplantations in a single center: Across immunological barriers.

AbstractKidney transplant (KT) is the optimal renal replacement therapy for patients with end-stage renal disease (ESRD). The demand for kidneys, however, continues to exceed the supply. To overcome this problem, efforts to extend the donor pool by including human leukocyte antigen (HLA)- and ABO-incompatible (ABOi) KTs are increasing. The aim of this article was to retrospectively review data on recipients, donor profiles, and clinical outcomes in 4000 cases of KT. In addition, we analyzed clinical outcomes in ABOi and flow-cytometric crossmatch (FCXM) positive KT in a subgroup analysis.This was a retrospective, observational study using data extracted from medical records. A total of 4000 consecutive patients who underwent KT at our institution from January 1990 to February 2015 were included in this study. KTs across immunological barriers such as ABO incompatible (276 cases, 6.9%), FCXM positive (97 cases, 2.4%), and positive complement-dependent cytotoxicity (CDC) XM KT (16 cases, 0.4%) were included.From a Kaplan–Meier analysis, overall patient survival (PS) rates after KT at 1, 5, 10, and 20 years were 96.9%, 95.1%, 92.0%, and 88.9%, respectively. The overall graft survival (GS) rates after KT at 1, 5, 10, and 20 years were 96.3%, 88.9%, 81.2%, and 67.4%, respectively. Our subgroup analysis suggested that overall PS, GS, death-censored GS, and rejection-free GS in ABOi KT showed no significant differences in comparison with ABO-compatible KT if adequate immunosuppressive treatment was performed. The overall PS rate in patients who underwent FCXM positive KT did not differ significantly from that of the control group during the 3-year follow-up (P = 0.34). The overall GS, death-censored GS, and rejection-free GS also did not differ significantly between the FCXM KT and control groups (P = 0.99, 0.42, and 88).The outcomes of KTs continually improved during the study period, while the annual number of KTs increased. ABO or FCXM positive KTs can be performed safely with successful graft outcomes.

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.