Wan Kee Kim

Long-Term Outcomes of Mechanical Valve Replacement in Patients with Atrial Fibrillation: Impact of the Maze Procedure

Background— The long-term benefits of the maze procedure in patients with chronic atrial fibrillation undergoing mechanical valve replacement who already require lifelong anticoagulation remain unclear. Methods and Results— We evaluated adverse outcomes (death; thromboembolic events; composite of death, heart failure, or valve-related complications) in 569 patients with atrial fibrillation–associated valvular heart disease who underwent mechanical valve replacement with (n=317) or without (n=252) a concomitant maze procedure between 1999 and 2010. After adjustment for differences in baseline risk profiles, patients who had undergone the maze procedure were at similar risks of death (hazard ratio, 1.15; 95% confidence interval, 0.65–2.03; P=0.63) and the composite outcomes (hazard ratio, 0.82; 95% confidence interval, 0.50–1.34; P=0.42) but a significantly lower risk of thromboembolic events (hazard ratio, 0.29; 95% confidence interval, 0.12–0.73; P=0.008) compared with those who underwent valve replacement alone at a median follow-up of 63.6 months (range, 0.2–149.9 months). The effect of superior event-free survival by the concomitant maze procedure was notable in a low-risk EuroSCORE (0–3) subgroup (P=0.049), but it was insignificant in a high-risk EuroSCORE (≥4) subgroup (P=0.65). Furthermore, the combination of the maze procedure resulted in superior left ventricular (P<0.001) and tricuspid valvular functions (P<0.001) compared with valve replacement alone on echocardiographic assessments performed at a median of 52.7 months (range, 6.0–146.8 months) after surgery. Conclusion— Compared with valve replacement alone, the addition of the maze procedure was associated with a reduction in thromboembolic complications and improvements in hemodynamic performance in patients undergoing mechanical valve replacement, particularly in those with low risk of surgery.

Outcomes of Acute Retrograde Type A Aortic Dissection With an Entry Tear in Descending Aorta

Background— Optimal management strategy of acute aortic dissection (AD) with retrograde extension from entry tear in the descending aorta into the ascending aorta remains undetermined. Methods and Results— Of the 538 patients who were diagnosed as having acute AD from 1999 through 2011, 49 patients (37 men; 52.5±13.1 years) were identified as having entry tear in the descending aorta with retrograde extension of AD into the ascending aorta. Sixteen patients who were clinically stable with thrombosed false lumen in the ascending aorta were treated medically (MED group), whereas 33 patients underwent aortic replacement (SURG group) on an intention-to-treat basis. In the MED group, 1 patient was converted to urgent aortic surgery and 2 patients underwent endovascular stent grafting in the descending aorta during the initial hospitalization. The early (30-day or in-hospital) mortality rates were 0% and 9.1% in the MED and SURG group, respectively (P=0.54). Follow-up was complete in all patients (median, 61.4 months; Q1–Q3, 28.2–99.1 months). The 5-year 100% survival rate in the MED group was higher than that in the SURG group (81.2±7.0%; P=0.080), in the surgically treated patients with antegrade type A AD (74.5±2.8%; P=0.038), and in the patients with type B AD (75.3±3.3%; P=0.045). Aortic event–free survival at 5 years was 52.7±14.8% and 69.6±8.0% in the MED and SURG groups, respectively (P=0.98). Conclusions— Patients with acute retrograde type A AD showed a more favorable prognosis than patients with antegrade AD. In selected patients with retrograde type A AD, excellent outcomes could be achieved with initial medical management combined with timely interventions.

Titanium plate fixation for sternal dehiscence in major cardiac surgery.

Background Sternal dehiscence is one of the most troublesome complications following cardiac surgery. Treatment failure and consequent lethal outcomes are very common. The aim of this study was to evaluate titanium plate fixation as a treatment for sternal dehiscence following major cardiac surgery. Materials and Methods Between 2010 and 2012, 17 patients underwent sternal reconstruction using horizontal titanium plating for the treatment of post-cardiac-surgery sternal dehiscence. The plates were cut and shaped, and then were fixed to corresponding costal segments using 2-3 titanium screws per each side. Results The median age of our patients was 66 years (range, 50 to 78 years) and 9 were female. Indications for sternal reconstruction included aseptic sternal dehiscence in 3 patients and osteomyelitis in 14 patients including 6 patients who were diagnosed with mediastinitis. During the operation, sternal resection and autologous flap interposition were combined in 11 patients. One patient died due to sepsis. Two patients required additional soft tissue wound revisions. Another patient presented with a tuberculous wound infection which was resolved using anti-tuberculosis medications. The postoperative course was uncomplicated in the other 13 patients. Conclusion Titanium plate fixation that combines appropriate debridement and flap interposition is very effective for the treatment of sternal dehiscence following major cardiac surgery.

Clinical outcomes in 1731 patients undergoing mitral valve surgery for rheumatic valve disease

Objective Unlike degenerative mitral valve (MV) disease, the advantages of valve repair procedure over replacement have been debated in rheumatic MV disease. This study aims to evaluate the impact of procedural types on long-term outcomes through analyses on a large data set from an endemic area of rheumatic disease. Methods We evaluated 1731 consecutive patients (52.3±12.5 years; 1190 women) undergoing MV surgery for rheumatic MV disease between 1997 and 2015. Long-term survival and valve-related outcomes were compared between repair and replacement procedures. To adjust for selection bias, propensity score analyses were performed. Results Patients undergoing repair were younger and had more predominant mitral regurgitation than mechanical and bioprosthetic replacement groups (61.6% vs 15.6% vs 24.4%; P<0.001). During follow-up (130.9±27.7 months), 283 patients (16.3%) died and 256 patients (14.8%) experienced valve-related complications. Propensity score matching yielded 188 pairs of repair and replacement patients that were well balanced for baseline covariates. In the matched cohort, there was no significant difference in the mortality risk between the repair and replacement groups (HR, 1.24; 95% CI 0.62 to 2.48). The risk of composite valve-related complications, however, was significantly lower in repair group (HR, 0.57; 95% CI 0.33 to 0.99) principally derived by a lower risk of haemorrhagic events (HR, 0.23; 95% CI 0.07 to 0.70). The incidence of reoperation was not significantly different between groups in the matched cohort (HR, 1.62; 95% CI 0.49 to 5.28). Conclusion Valve repair in well-selected patients with severe rheumatic MV disease led to comparable survival, but superior valve-related outcomes compared with valve replacement surgery.

Extracorporeal life support for adults with refractory septic shock

Objective Although the use of extracorporeal membrane oxygenation (ECMO) in shock patients is increasing worldwide, studies concerning this treatment for adult septic shock are limited. This study aimed to analyze the outcome of venoarterial ECMO in adult patients with septic shock refractory to conventional treatment. Methods A total of 71 consecutive patients who presented with septic shock and underwent venoarterial ECMO were reviewed. Clinical parameters were compared between survivors and nonsurvivors. Weaning and survival outcomes of these patients were compared with the control group of 253 patients who received venoarterial ECMO for cardiogenic shock. Results The mean age was 56.0 ± 12.3 years. Of the 71 septic shock patients, 11 (15.5%) were successfully weaned from ECMO after a median of 7.9 [interquartile range (IQR), 6.3‐10.2] days, 5 of whom (7.0%) survived to discharge. Pre‐ and 6 hours post‐procedural lactate levels were significantly higher in the nonsurvivors (11.6 [IQR, 7.5‐15.0] vs 5.8 [IQR, 4.3‐5.9], P = .036; 15.0 [IQR, 11.1‐15.0] vs 5.2 [IQR, 4.7‐5.4], P = .002). Rates of successful weaning from venoarterial ECMO (15.5% vs 45.5%), and of survival up to hospital discharge (7.0% vs 28.9%) were significantly lower in septic shock than in cardiogenic shock patients (n = 253; P < .001). Conclusions Outcomes of ECMO in refractory septic shock patients were poor with a very low probability of survival. This finding raises questions concerning the utility of applying ECMO for medically refractory septic shock. Elevated arterial lactate levels pre‐ and post‐ECMO were associated with risk of in‐hospital death. Further large‐scale studies are needed to validate the results of this study.

Titanium Plate Fixation for a Dehisced Sternum Following Coronary Artery Bypass Grafting: A Case Report

Sternal dehiscence is one of the most troublesome complications following cardiac surgery. Treatment failure and consequent lethal results are very common, even with all the efforts to resolve sternal dehiscence such as removal of infectious tissue, muscle flap interposition, and sternal rewiring. We report on a case of sternal osteomyelitis following coronary artery bypass grafting that was successfully treated with wide sternal resection, titanium plate fixation, and pectoralis muscle flap interposition.

Concomitant Ablation of Atrial Fibrillation in Rheumatic Mitral Valve Surgery

Objective: Efficacy of atrial fibrillation ablation in rheumatic mitral valve disease has been regarded inferior to that in nonrheumatic diseases. This study aimed to evaluate net clinical benefits by the addition of concomitant atrial fibrillation ablation in rheumatic mitral valve surgery. Methods: Among 1229 consecutive patients with atrial fibrillation from 1997 to 2016 (54.4 ± 11.7 years; 68.2% were female), 812 (66.1%) received concomitant ablation of atrial fibrillation (ablation group), and 417 (33.9%) underwent valve surgery alone (no ablation group). Death and thromboembolic events were compared between these groups. Mortality was regarded as a competing risk to evaluate thromboembolic outcomes. To reduce selection bias, inverse probability of treatment weighting methods were performed. Results: Freedom from atrial fibrillation occurrence at 5 years was 76.5% ± 1.8% and 5.3% ± 1.1% in the ablation and no ablation groups, respectively (P < .001). The ablation group had significantly lower risks for death (hazard ratio [HR], 0.69; 95% confidence interval [CI], 0.52‐0.93) and thromboembolic events (HR, 0.49; 95% CI, 0.32‐0.76) than the no ablation group. Time‐varying Cox analysis revealed that the occurrence of stroke after surgery was significantly associated with death (HR, 3.97; 95% CI, 2.36‐6.69). In subgroup analyses, the reduction in the composite risk of death and thromboembolic events was observed in all mechanical (n = 829; HR, 0.53; 95% CI, 0.39‐0.73), bioprosthetic replacement (n = 239; HR, 0.67; 95% CI, 0.41‐1.08), and repair (n = 161; HR, 0.17; 95% CI, 0.06‐0.52) subgroups (P for interaction = .47). Conclusions: Surgical atrial fibrillation ablation during rheumatic mitral valve surgery was associated with a lower risk of long‐term mortality and thromboembolic events. Therefore, atrial fibrillation ablation for rheumatic mitral valve disease may be a reasonable option.

Granulomatosis With Polyangiitis Involving the Ascending Aorta

A 58-year-old man visited the emergency department with vague anterior chest discomfort. From the computed tomographic findings, our initial suspicion was intramural hematoma in the ascending aorta. After a comprehensive discussion with relevant departments, emergent operation was planned. Intrapericardial space, however, was severely adhered, suggesting chronic inflammation. Biopsies were performed, and additional surgical procedures were discontinued. The patient was finally diagnosed as having granulomatosis with polyangiitis. Careful approach with high-degreed suspicion for granulomatosis with polyangiitis, although rare, is required when preoperative findings are similar to the present case.

3D-Printing-Based Open Repair of Extensive Thoracoabdominal Aorta in Severe Scoliosis

3D-printing-based surgical repair of complex thoracoabdominal aortic disease may be a useful approach to enhance procedural efficiency. CASE REPORT A 58-year-old female with Marfan syndrome admitted for planned surgical repair of chronic type B aortic dissection. The patient had undergone David I procedure combined with prophylactic total-arch repair 6 months ago to treat severe aortic valve regurgitation associated with aortic root aneurysm in our institution. At the present admission, computed tomography (CT) images showed severely tortuous and dilated thoracoabdominal aorta (TAA) along with severe scoliosis (Fig. 1A). The origins of each visceral, renal and segmental arteries were markedly displaced in accordance with severe tortuosity of the aorta. In order to overcome these anatomical challenges, we decided to build up an anatomical model using 3D-printing technology. At first, virtual modeling was designed to mimic the native aorta and its major branches based on the patients CT images (Fig. 1B). Based on these 3D-images, a referential virtual 3D-artificail graft respecting the tortuosity of the aorta fitted to the scoliosis was created. Finally, the 3D aortic model was printed using VisiJet PXL Core powder, VisiJet PXL clear binder, and Color bonds. Thereafter, actual aortic graft was constructed in accordance with 3D-printed aortic model before skin incision. During anesthetic induction, resected 10-mm-side branches were manually connected to commercialized aortic graft (Gelweave coselli thoracoabdominal graft 28 mm; Vascutek Ltd, Renfrewshire, UK) targeting intercostal branches. The planned surgical extent was from distal end of the

del Nido cardioplegia in adult cardiac surgery: beyond single-valve surgery†

OBJECTIVES In recent years, the use of del Nido (DN) cardioplegia has been reported in single-valve surgery or isolated coronary artery bypass surgery with acceptable outcomes. The reports of its use in more complex adult cardiac procedures, however, have been scarce. METHODS We enrolled a total of 149 adult patients who underwent heart valve surgery with the use of DN cardioplegia between May 2014 and December 2016. For a benchmark comparison, 892 patients who underwent cardiac valve surgery with blood cardioplegia during the same period served as controls. To reduce selection bias, propensity score matching was used; the inverse probability of treatment weighting method was performed for further validations. RESULTS Overall, 57.7% of patients in the DN group underwent multiple or complex cardiac procedures. Early mortality rates were 0.7% and 2.4% in the DN and blood groups, respectively (P = 0.31). Propensity score matching yielded 111 pairs of patients who were well balanced for all 23 measured baseline covariates. In the matched cohort, the postoperative peak troponin I levels (P = 0.004) and the aortic clamping times (P < 0.001) were significantly lower and shorter compared with those in the blood group. There were no significant differences in early mortality rates (1.9% vs 0%, P > 0.99), low cardiac output (P = 0.57) and neurological events (P = 0.21). The quantities of postoperative transfusions (P = 0.008) and fluid supplements (P < 0.001) were significantly lower in the matched DN group compared with the blood group. CONCLUSIONS The use of DN in adult valve surgery including complex procedures may confer acceptable outcomes comparable to or even superior to those obtained with the use of blood cardioplegia.