Transit Time Flowmetry and Vein Size Are Predictive of Arteriovenous Fistula Maturation

Background@#This study aimed to assess the effect of vessel size and flow characteristics on the maturation of autogenous radiocephalic arteriovenous fistulae (RCAVFs). @*Methods@#We retrospectively reviewed records of patients undergoing RCAVF creation at a single medical center from January 2013 to December 2019. Operative variables were compared between patients whose fistulae matured and those whose fistulae failed to mature. @*Results@#Overall, 152 patients (33 of whom were women) with a mean age of 62.6±13.6 years underwent RCAVF creation; functional maturation was achieved in 123. No statistically significant differences were observed between patients in whom maturation was or was not achieved in terms of the following variables: female sex (20.3% vs. 25.0%), radial artery size (2.5 vs. 2.4 mm), and pulsatility index (0.69 vs. 0.62). Low intraoperative transit time flowmetry (TTF; 150.4 vs. 98.1 mL/min) and small vein size (2.4 vs. 2.0 mm) were associated with failure of maturation. The best cutoff diameter for RCAVF TTF and cephalic vein size were 105 mL/min and 2.45 mm, respectively. @*Conclusion@#In patients who undergo RCAVF creation, vein diameter on preoperative ultrasonography and intraoperative TTF are predictors of functional maturation. We identified an intraoperative TTF cutoff value that can be used for intraoperative decision-making.

Extracorporeal Life Support in Adult Patients with Hematologic Malignancies and Acute Circulatory and/or Respiratory Failure

BACKGROUND@#The primary goal of this study was to characterize the clinical outcomes of adult patients with hematologic malignancies (HM) who were treated with extracorporeal membrane oxygenation (ECMO) support when conventional treatments failed.@*METHODS@#In this retrospective, observational study at a tertiary medical center, we reviewed the clinical course of 23 consecutive patients with HM requiring ECMO who were admitted to the intensive care unit at Asan Medical Center from March 2010 to April 2015.@*RESULTS@#A total of 23 patients (8 female; median age, 44 years; range, 29–51 years) with HM and severe acute circulatory and/or respiratory failure received ECMO therapy during the study period. Fourteen patients received veno-arterial ECMO, while 9 patients received veno-venous ECMO. The median ECMO duration was 104.7 hours (range, 37.1–221 hours). Nine patients were successfully weaned from ECMO. The in-hospital mortality rate was 91.1% (21 of 23). There were complications in 3 patients (cannulation site bleeding, limb ischemia, and gastrointestinal bleeding).@*CONCLUSION@#ECMO is a useful treatment for patients with circulatory and/or pulmonary failure. However, in patients with HM, the outcomes of ECMO treatment results were very poor, so it is advisable to carefully decide whether to apply ECMO to these patients.

Extracorporeal Life Support in Adult Patients with Hematologic Malignancies and Acute Circulatory and/or Respiratory Failure / 대한흉부외과학회지

BACKGROUND: The primary goal of this study was to characterize the clinical outcomes of adult patients with hematologic malignancies (HM) who were treated with extracorporeal membrane oxygenation (ECMO) support when conventional treatments failed. METHODS: In this retrospective, observational study at a tertiary medical center, we reviewed the clinical course of 23 consecutive patients with HM requiring ECMO who were admitted to the intensive care unit at Asan Medical Center from March 2010 to April 2015. RESULTS: A total of 23 patients (8 female; median age, 44 years; range, 29–51 years) with HM and severe acute circulatory and/or respiratory failure received ECMO therapy during the study period. Fourteen patients received veno-arterial ECMO, while 9 patients received veno-venous ECMO. The median ECMO duration was 104.7 hours (range, 37.1–221 hours). Nine patients were successfully weaned from ECMO. The in-hospital mortality rate was 91.1% (21 of 23). There were complications in 3 patients (cannulation site bleeding, limb ischemia, and gastrointestinal bleeding). CONCLUSION: ECMO is a useful treatment for patients with circulatory and/or pulmonary failure. However, in patients with HM, the outcomes of ECMO treatment results were very poor, so it is advisable to carefully decide whether to apply ECMO to these patients.

Surgical Outcomes of Radiographically Noninvasive Lung Adenocarcinoma according to Surgical Strategy: Wedge Resection, Segmentectomy, and Lobectomy

BACKGROUND: The aim of this study was to evaluate the outcomes of surgical resection in patients with radiographically noninvasive lung adenocarcinoma according to the surgical strategy. METHODS: A retrospective study was conducted of 128 patients who underwent pulmonary resection for ground-glass opacity (GGO)–dominant nodules measuring ≤2 cm with a consolidation/tumor ratio ≤0.25 based on computed tomography between 2008 and 2015. The 5-year disease-free survival (DFS) rate and 5-year overall survival (OS) rate were analyzed. RESULTS: Among the 128 patients, wedge resection, segmentectomy, and lobectomy were performed in 40 (31.2%), 22 (17.2%), and 66 patients (51.6%), respectively. No significant differences were found among the groups in the mean size of tumors (p=0.119), the rate of pure-GGO nodules (p=0.814), the consolidation/tumor ratio (p=0.695), or the rate of invasive adenocarcinoma (p=0.378). Centrally located tumors were more common in the lobectomy group (21.2%) than in the wedge resection (0%) or segmentectomy (0%) groups (p=0.001). There were no significant differences in the 5-year DFS rate (100%, 100%, 92.7%, respectively; p=0.76) or 5-year OS rate (100%, 100%, 100%; p=0.223) among the wedge resection, segmentectomy, and lobectomy groups. CONCLUSION: For radiographically noninvasive lung adenocarcinoma measuring ≤2 cm with a consolidation/tumor ratio ≤0.25, wedge resection and segmentectomy could be comparable surgical options to lobectomy.

A Minimally Invasive Approach for the Treatment of Mid-Aortic Syndrome in Takayasu Arteritis

A 61-year-old woman who presented with claudication and dyspnea on exertion was found to have severe calcified narrowing of the descending aorta and severe insufficiency of the aortic valve. These findings were compatible with Takayasu arteritis. To treat these hemodynamic abnormalities, extra-aortic bypass surgery combined with replacement of the aortic valve and ascending aorta-to-hemiarch replacement was performed through a separated upper hemi-sternotomy and limited median laparotomy. We present our successful surgical experience with this case.

Surgical Outcomes of Cardiac Myxoma: Right Minithoracotomy Approach versus Median Sternotomy Approach

BACKGROUND: The standard approach in treating cardiac myxoma is the median full sternotomy. With the evolution of surgical techniques, the right minithoracotomy approach has emerged as an alternative method. Since few studies have been published assessing the right minithoracotomy approach, we performed a retrospective study to compare the clinical outcomes of the right minithoracotomy approach with those of the sternotomy approach. METHODS: From January 2005 to December 2014, 203 patients underwent resection of a cardiac myxoma. Patients with preexisting cardiac problems were excluded from this study. 146 patients were enrolled in this study; 83 patients were treated using a median sternotomy and 63 patients were treated using a right minithoracotomy. RESULTS: No early mortalities were recorded in either group. Although the cardiopulmonary bypass time and aorta cross-clamp time were significantly shorter in the sternotomy group (p<0.001 and p=0.005), postoperative blood transfusions and arrhythmia events were significantly less common in the thoracotomy group (p=0.004 and p=0.025, respectively). No significant differences were found in the duration of the hospital stay, postoperative intubation time, the duration of the intensive care unit stay, and recurrence. CONCLUSION: The minimally invasive right minithoracotomy approach is a good alternative method for treating cardiac myxoma because it was found to be associated with a lower incidence of postoperative complications and a shorter postoperative recovery period.

Essential Thrombocytosis-Associated Thromboembolism in the Abdominal Aorta

Essential thrombocytosis (ET) is a myeloproliferative disorder characterized by an anomalous increase in platelet production. Many patients with ET are asymptomatic. Few studies have reported ET-associated thromboembolism in large vessels such as the aorta. We report a patient with ET who presented with peripheral embolism from an abdominal aortic thrombus and developed acute limb ischemia. The patient underwent aortic replacement successfully. The patient’s platelet count was controlled with hydroxyurea, and no recurrence was noted over 2 years of follow-up.

Huge Pseudoaneurysm of Popliteal Artery Following Conservative Treatment of a Distal Femur Fracture: A Case Report

A pseudoaneurysm is a contained arterial disruption in the intimal and medial layers of an arterial wall. It may originate from a perforation caused by traumatic or iatrogenic injury or the dehiscence of a surgical anastomosis. Because of its insidious onset and delayed presentation, orthopaedic surgeons should be aware of the possibility of such a lesion after an initial trauma. We report on a case of a delayed huge pseudoaneurysm of the popliteal artery that occurred 11 months after conservative treatment of a supracondylar fracture of the femur in order to keep in mind the possibility of the delayed presentation of vascular injury after a distal femur fracture.

Fixation of Traumatic Sternal Fractures Using SternaLock Plating System

A 43-year-old man experienced chest trauma due to a car accident. Compound sternal fractures with severe dislocation were seen on computed tomography of the chest. Using a SternaLock plating system with manual reduction, fixation of the sternal fracture was successfully performed. There were no complications related to the operation.

Removal of Kirschner Wire That Migrated from the Pelvic Bone into the Right Ventricle of the Heart

A sixty-year-old man was admitted due to chest pain. He had a history of pelvic bone fracture fixation with Kirschner wire about 20 years earlier. On examination, we detected a Kirschner wire that had migrated into the right ventricle. Without cardiopulmonary bypass, we removed the migrating Kirschner wire via median sternotomy. The patient recovered without complications and was discharged on the 5th postoperative day.

Aortic Valve Replacement for Aortic Stenosis and Concomitant Coronary Artery Bypass: Long-term Outcomes and Predictors of Mortality

BACKGROUND: We evaluated the surgical results and predictors of long-term survival in patients who underwent coronary artery bypass grafting (CABG) at the time of an aortic valve replacement (AVR) due to aortic stenosis. MATERIALS AND METHODS: Between January 1990 and December 2009, 183 consecutive patients underwent CABG and concomitant aortic valve replacement for aortic stenosis. The mean follow-up period was 59.8+/-3.3 months and follow-up was possible in 98.3% of cases. Predictors of mortality were determined by Cox regression analysis. RESULTS: There were 5 (2.7%) in-hospital deaths. Follow-up of the in-hospital survivors documented late survival rates of 91.5%, 74.8%, and 59.6% at 1, 5, and 10 postoperative years, respectively. Age (p<0.001), a glomerular filtration rate (GFR) less than 60 mL/min (p=0.006), and left ventricular (LV) mass (p<0.001) were significant predictors of mortality in the multivariate analysis. CONCLUSION: The surgical results and long-term survival of aortic valve replacement with concomitant CABG in patients with aortic stenosis and coronary artery disease were acceptable. Age, a GFR less than 60 mL/min, and LV mass were significant predictors of mortality.

The Decellularized Vascular Allograft as an Experimental Platform for Developing a Biocompatible Small-Diameter Graft Conduit in a Rat Surgical Model

PURPOSE: The present study was aimed to assess the feasibility of using decellularized aortic allograft in a rat small animal surgical model for conducting small diameter vascular tissue engineering research. MATERIALS AND METHODS: Decellularized aortic allografts were infra-renally implanted in 12 Sprague-Dawley (SD) adult rats. The conduits were harvested at 2 (n = 6) and 8 weeks (n = 6), and assessed by hematoxylin and eosin (H&E), van Gieson, Masson Trichrome staining, and immunohistochemistry for von Willebrand factor, CD 31+, and actin. RESULTS: Consistent, predictable, and reproducible results were produced by means of a standardized surgical procedure. All animals survived without major complications. Inflammatory immune reaction was minimal, and there was no evidence of aneurysmal degeneration or rupture of the decellularized vascular implants. However, the aortic wall appeared thinner and the elastic fibers in the medial layer showed decreased undulation compared to the normal aorta. There was also minimal cellular repopulation of the vascular media. The remodeling appeared progressive from 2 to 8 weeks with increased intimal thickening and accumulation of both collagen and cells staining for actin. Although the endothelial like cells appeared largely confluent at 8 weeks, they were not as concentrated in appearance as in the normal aorta. CONCLUSION: The results showed the present rat animal model using decellularized vascular allograft implants to be a potentially durable and effective experimental platform for conducting further research on small diameter vascular tissue engineering.

Orthotopic Cardiac Transplantation after Inter-caval Anastomosis in a Patient with Hypertrophic Cardiomyopathy and Persistent Left Superior Vena Cava / 대한흉부외과학회지

Cardiac transplantation in a patient with persistent left superior vena cava (SVC) necessitates unifocalization of the caval veins. Here we report a successful case of orthotopic heart transplantation in a patient with hypertrophic cardiomyopathy and persistent left SVC. Cardiac transplantation was done after the left SVC was anastomosed to the right SVC in an end to side fashion. The postoperative course was uneventful, and the patient is currently in an excellent clinical condition.

Midterm Results of Aortic Valve Replacement Using Tissue Valve / 대한흉부외과학회지

BACKGROUND: The durability of the tissue valve is important in choice between a mechanical valve and a tissue valve in cardiac surgery. We studied the mid-term results of tissue valve in the aortic position. MATERIAL AND METHOD: The subjects were 380 patients who had undergone aortic prosthesis replacement between May 1990 and March 2009. We retrospectively analyzed hospital and outpatient records: the mean age was 69+/-9 years; the male to female ratio was 227 : 162; and the mean follow-up duration was 46.7+/-40.8 months (range 0~196 months). RESULT: 389 surgical cases in total had been taken with 380 patients. Early death occurred in 15 patients (3.9%). Overall survival rate at 1, 5 and 10 years were 92.3%, 78.1% and 54.2% respectively. Freedom from reoperation at 1, 5 and 10 years were 98.4%, 97.1% and 91.7% respectively. Freedom from structural valvular deterioration at 1, 5 and 10 years were 96.1%, 92.3% and 88.0% respectively. In the multivariate analysis of preoperative risk factors, young age (p<0.001) was significant risk factor for reoperation. High peak velocity in the postoperative period (p=0.034) and young age (p=0.029) were significant risk factors for structural valvular deterioration. Old age (p=0.001), long bypass time (p=0.035), concomitant coronary artery bypass graft surgery (p=0.003) and preoperative low left ventricular ejection fraction (p=0.003) were significant factors for early mortality. Preoperative estimated glomerular filtration rate (<60 mL/min) (p=0.025) and persistent left ventricular hypertrophy (p=0.032) were the risk factors for late mortality. CONCLUSION: This study showed that the freedom from reoperation and the freedom from structural valvular deterioration in aortic tissue valve replacement were acceptable. It will be necessary to conduct further studies with long-term follow-up and more patients.

Treating a Ruptured Ascending Aorta with an Endovascular Stent Graft / 대한흉부외과학회지

Endovascular stent grafting is regarded as a promising alternative approach to open surgical repair for treating various aortic diseases in high risk patients. We report here on a case of a 79-year-old female who underwent endovascular stent-graft insertion in the ascending aorta for treating a complicated ascending aortic rupture that occurred secondary to radiation necrosis during the treatment of recurrent breast cancer.

Alternative Energy Sources for Surgical Treatment of Atrial Fibrillation in Patients Undergoing Mitral Valve Surgery: Microwave Ablation vs Cryoablation

The study aim was to compare maze outcomes using microwave ablation or cryoablation in patients with mitral disease and atrial fibrillation (AF). Between 1999 and 2005, 340 patients underwent mitral valve surgery and concomitant maze procedure involving either microwave ablation (n=96, MW group) or cryoablation (n=244, Cryo group). Mean age at operation was 50.0+/-12.5 yr. Follow-up period was 46.1+/-28.2 months. The Cryo group showed a longer aortic clamping time than the MW group (P=0.005). There were no differences in operative mortality and morbidity rates. The unadjusted 5-yr AF free rate was 61.3+/-1.2% in the MW group and 79.9+/-3.2% in the Cryo group (P=0.089). After adjustment, the MW group only showed a tendency toward more frequent AF recurrence than the Cryo group (Hazard ration 1.66, 95% confidence interval 0.89 to 3.07). Multivariate analysis revealed that older patient age (P<0.001) and greater left atrial size (P<0.001) were independent risk factors for AF recurrence. Although the use of microwave ablation results in shorter aortic clamping time, it has a tendency toward more frequent late AF recurrence than with cryoablation.

Change of the Left Atrial Dimension and Transport Function after the Cox-Maze Procedure for Treating Atrial Fibrillation Associated with Mitral Valve Disease: the Short-term and Mid-Term Results / 대한흉부외과학회지

BACKGROUND: Although the high efficiency of conversion into sinus rhythm has been demonstrated after performing the Cox-Maze procedure in patients with atrial fibrillation associated with mitral valve disease, the changes in the mechanical function and size of the left atrium have not been determined. The aim of this study was to evaluate the effect of the Maze procedure on the left atrial size and contractile transport function. MATERIAL AND METHOD: From July 1997 to July 2008, 647 consecutive patients were operated on for chronic atrial fibrillation associated with mitral valve disease. Among these, 211 patients that (1) were able to be followed up for 2 years after surgery, (2) had sustained normal sinus rhythm, regardless of whether they were taking anti-arrhythmic medications and (3) did not have valvular regurgitation greater than grade III or they did not have moderate grade valvular stenosis were selected for evaluation. The left atrial size and contractile transport function were assessed by transthoracic echocardiography at the postoperative base line (1 year) and at regular follow-up periods (2 years, 3 years, 4 years and 6 year). RESULT: The left atrial dimension was increased and the contractile transport function was decreased during the follow-up period. The longer the follow-up period, the greater was the statistical significance of the left atrial size increase and contractile transport function decrease. CONCLUSION: In patients who sustain normal sinus rhythm conversion after a Maze III procedure with a mitral valve operation, there is a gradual increase of the left atrial dimensions and a decrease of contractile transport function during the follow-up period. Therefore, scrupulous follow-up is needed for these patients.

Comparison of the Neurologic Outcome according to the Method of Proximal Graft Anastomosis at the Aortic Side during Off-pump Coronary Artery Bypass Grafting: The Heartstring Sealing System versus Conventional Manual Anastomosis / 대한흉부외과학회지

BACKGROUND: Side clamping of ascending aorta during proximal graft anastomosis in coronary bypassing surgery increases the risk of direct aortic injury as well as embolization of intimal atheroma. Heartstring proximal sealing system (Guidant Corporation, Santa Clara, Calif), developed to avoid aortic side clamping, may minimize risks of such complications. The aim of the current study is to compare the surgical outcomes of the two proximal anastomosis techniques i.e., Heartstring system versus aortic side clamping in off pump coronary bypassing surgery (OPCAB). MATERIAL AND METHOD: From January 2003 to August 2008, 499 patients underwent OPCAB. Of them, proximal graft anastomosis was performed using Heartstring system in 182 patients (Group I) and conventional manual anastomosis in 317 patients (Group II). The two groups were compared for postoperative major complications and mortality. RESULT: Two groups showed similar characteristics in terms of preoperative demographic data, left ventricular ejection fraction, renal function and history of diabetes, hypertension and smoking. Although there was no inter-group difference in the history of cerebral ischemia (p=0.48), preoperative brain magnetic resonance angiography revealed greater incidence of severe carotid artery stenosis (>75% of lumen) in the Group I than in the Group II (44.5% in the Group I and 30.0% in the Group II, p=0.003). There were no inter-group differences in postoperative mortality (p=0.40) and complications (p=0.47) including neurologic events (3 in the Group I and 2 in the Group II, p=0.258). Whereas neurologic events all comprised transient ischemic attacks in the Group I, they comprised multiple embolic strokes in the Group II. One patient in the Group II experienced aortic dissection during proximal anastomosis which resulted in ascending aortic replacement. CONCLUSION: Although proximal anastomosis using Heartstring system did not show statistically significant benefit over aortic side clamping, the absence of embolic stroke may be a definite benefit which may be better defined through further studies over a larger cohort.

Comparison of Mitral Valve Repair between a Minimally Invasive Approach and a Conventional Sternotomy Approach / 대한흉부외과학회지

BACKGROUND: Minimally invasive cardiac surgery appears to offer certain advantages such as earlier postoperative recovery and a greater cosmetic effect than that achieved through conventional sternotomy. However, this approach has not yet been widely adopted in Korea to replace complex open heart surgery such as mitral valve reconstruction. This study compared the results of robot assisted minimally invasive mitral valve repair with those results of conventional sternotomy. MATERIAL AND METHOD: From December 1993 to December 2005, 520 consecutive patients underwent mitral valve reconstruction for mitral regurgitation in our institution. These patients were subdivided according to those whose surgery used the conventional sternotomy approach (Group S, n=432) and those who underwent minimally invasive right anterior thoracotomy (Group M, n=88); we then compared the clinical results of both groups. When we performed minimally invasive right thoracotomy, we used a robot (AESOP 3000) and made an incision less than 5 cm. RESULT: Our study patients in both groups were similar for their age, gender and preoperative ejection fraction. There were two hospital mortalities in group S. but there was no mortality in the group M patients. Significant reductions in the ICU stay and the postoperative hospital stay were observed in the group M patients compared with the group S patients. However, both the bypass time and the aortic cross-clamp time were significantly longer in the group M patients. In spite of the confined incision in the group M patients, there were no limitations on the mitral valve repair techniques. There was a similar frequency of postoperative significant residual mitral regurgitation in both groups. CONCLUSION: In this study, the minimally invasive mitral valve repair showed comparable early results with the conventional sternotomy patients. We will now need long-term follow-up of these patients who underwent minimally invasive mitral valve repair, but we anticipate that based on the results of this study, we will begin to routinely perform minimally invasive cardiac surgery as our primary approach for mitral valve reconstruction.

A Posterior Annuloplasty, Papillary Muscle Plication and Left Ventricle Reduction Through Left Ventriculotomy in Severe Ischemic Cardiomyopathy with Mitral Regurgitation / 대한흉부외과학회지

In the mitral regurgitation (MR) accompanied with a serious ischemic cardiomyopathy (ICMP), coronary revascularization to viable myocardium, LV reduction and mitral reconstruction become the main surgery under the bad conditions that the cardiac transplantaton is not so easy. The MR in ischemic cardiomyopathy appears as various pathologic factors, among them, the papillary muscle displacement in addition to the annular dilatation is pointed out as the important cause. Our hospital would like to report the experience of the surgery about coronary revascularization to the left main with 3-vessel coronary disease, severe ICMP patients accompanied with the MR, posterior mitral annuloplasty and papillary muscle plication through the LVtomy.