Sadanari Sawaki

On-pump beating-heart coronary artery bypass grafting after acute myocardial infarction has lower mortality and morbidity

OBJECTIVE The mortality of conventional coronary artery bypass grafting after acute myocardial infarction remains high. This study compared the clinical outcomes of patients undergoing conventional and on-pump beating-heart coronary artery bypass grafting and evaluated the efficacy of an on-pump beating-heart technique for the surgical treatment of these critically ill patients. METHODS Between January 1999 and March 2005, 61 patients underwent emergency coronary artery bypass grafting for acute myocardial infarction. In the first 23 patients, the conventional cardioplegic method was performed. In the most recent 38 patients, the on-pump beating-heart procedure was used without cardioplegic arrest. RESULTS A significant reduction occurred in the observed mortality between the conventional and on-pump beating groups (21.7% vs 2.6%, P = .04), despite a higher predicted mortality risk calculated by using EuroSCORE (9.0 +/- 1.6 vs 9.6 +/- 1.6, P = .048) and a greater use of a preoperative intra-aortic balloon pump (43.5% vs 78.9%, P = .005). On-pump beating-heart patients received fewer bypass grafts than conventional patients (2.0 vs 2.9, P = .001), but the internal thoracic artery was used more often in on-pump beating-heart patients (P = .014). Three patients in the conventional coronary artery bypass grafting group required new insertion of an intra-aortic balloon pump, whereas no patients required this in the on-pump beating-heart group (P = .220). Postoperative renal failure requiring hemodialysis occurred in 2 patients in the conventional coronary artery bypass grafting group but in no patients in the on-pump beating-heart group (P = .138). CONCLUSIONS On-pump beating-heart coronary artery bypass grafting is the preferred method of emergency myocardial revascularization for patients with acute myocardial infarction who might tolerate cardioplegic arrest poorly. It has lower postoperative mortality and morbidity than conventional coronary artery bypass grafting.

Clinical outcomes of medical treatment of acute type A intramural hematoma.

A retrospective study was performed in 30 patients who were treated for type A intramural hematoma from 1999 to 2008, of whom 24 were initially treated without surgical intervention. These 24 patients were followed up for 3.3 ± 3.5 years (range, 0 days to 10.0 years). Four hospital deaths occurred (hospital mortality, 16.7%), there were 2 late deaths, and 2 other patients needed an operation during the follow-up period. The event-free survival rate (freedom from death or surgery) at 5 years was significantly lower in patients with maximal aortic diameter ≤48 mm than in those with diameters <48 mm (28.6% ± 17.1% vs. 88.2% ± 7.8%). Maximal aortic diameter ≤48 mm and computed tomography findings of a small intimal defect were significant predictors of rupture or progression of ascending aortic dissection. The outcome of medical treatment for type A intramural hematoma was acceptable during both the early and late periods, but patients with a relatively large aortic diameter or an intimal defect in the ascending aorta have a high probability of adverse outcome, and must be considered for surgery.

Infected aortic aneurysm, purulent pericarditis, and pulmonary trunk rupture caused by methicillin-resistant Staphylococcus aureus

A 66-year-old woman presented with cardiac tamponade. Pericardiocentesis revealed purulent pericarditis. Enhanced computed tomography showed a saccular aneurysm of the aortic arch. An irregularly shaped and partially enhanced mass was seen adjacent to the aneurysm, which suggested development of a mycotic pseudoaneurysm. Surgical drainage was performed through a subxiphoid incision, and continuous irrigation was commenced. On the following day, however, massive bleeding was recognized through the drains. The patient was immediately transferred to the operating theater, and extracorporeal circulation was established. A perforation 1 cm in diameter was found on the anterior surface of the pulmonary trunk, and a large amount of pus came out from the tear. The ascending aorta and the arch were found to be infected. Surgical repair was impossible due to extensive infection, and the patient died. Methicillin-resistant Staphylococcus aureus was isolated from the pericardial effusion, blood, and intraluminal thrombus of the aortic aneurysm.

Late mortality and morbidity in elderly patients with mechanical heart valves.

A retrospective study was performed in patients under and over 65 years old implanted with a mechanical valve, to compare late mortality and morbidity. Of 381 patients who underwent mechanical valve replacement at Nagoya University in the 1990s, 357 (11 hospital deaths and 13 lost to follow-up; 96.4% follow-up rate) were followed up for 7.9 ± 3.3 years (2,811 patient-years). They were divided into two groups either side of 65 years of age at operation. The young and elderly patient groups contained 275 and 82 patients, respectively. The survival rate in the young group was 96.1% (95% confidence interval, 93.7%–98.5%) at 5 years and 92.0% (95% confidence interval, 88.3%–95.7%) at 10 years, which was significantly better than 88.0% (95% confidence interval, 80.6%–95.4%) at 5 years and 73.8% (95% confidence interval, 66.2%–85.4%) at 10 years in the elderly group. The two groups did not differ significantly in the incidence of thromboembolic events, bleeding events, endocarditis, or reoperation. We are also encouraged by the fact that mechanical valves are not a risk factor for late mortality or morbidity, even in elderly patients.

Traumatic ventricular septal defect following a stab wound to the chest

A 51-year-old man who had been suffering from depression stabbed himself in the chest with an ice pick. At presentation, an ice pick lodged in the left fifth intercostal space was moving synchronously with his heartbeat. Echocardiography revealed that the tip was penetrating the anterior wall of the right ventricle. Because the patient was tamponading, an emergency operation was carried out. The ice pick was removed following the establishment of a cardiopulmonary bypass and pericardiotomy. The perforation of the right ventricle was closed with a pledget-reinforced mattress stitch. On postoperative day 12, a holosystolic murmur was detected on auscultation. Transthoracic echocardiography revealed a ventricular septal defect 5 mm in diameter located near the apex. The pulmonary-tosystemic flow ratio was 1.1 by echocardiographic measurement. No sign of heart failure was present. Although it was agreed to manage the ventricular septal defect conservatively, careful echocardiographic follow-up is mandatory.

Three-port (one incision plus two-port) endoscopic mitral valve surgery without robotic assistance†

OBJECTIVES Totally endoscopic minimally invasive mitral valve surgery (MIMVS) is technically demanding and often performed with robotic assistance. We hypothesized that three-port video-assisted thoracic surgery (VATS) would facilitate endoscopic MIMVS and evaluated its feasibility and safety. METHODS From October 2010 to June 2016, we performed first-time MIMVS in 250 consecutive patients (122 male), with median age of 65 years (54-73 years, 25-75 percentile). The thoracic access ports comprised one small (3-5 cm) thoracotomy without a rib spreader plus two trocars (one for the endoscope and one for left-handed instruments), thus establishing triangular three-port VATS. Cannulas, an aortic clamp, and a left atrial retractor were inserted through the thoracotomy, and right-handed instruments were inserted through the remaining space. Cardiopulmonary bypass was established through a groin incision. RESULTS The etiology of the mitral valve lesion was myxomatous degeneration in 70% of patients, rheumatic disease in 9%, infectious endocarditis in 6%, and other conditions in 15%. Mitral valve repair was performed in 233 patients and replacement in 27. Two patients underwent conversion to replacement after attempted repair. Forty-nine patients underwent tricuspid annuloplasty, and 45 underwent the Maze procedure. One in-hospital death occurred within 30 days. Two patients developed stroke, three underwent re-exploration for bleeding, one developed low output syndrome, and one required new haemodialysis. The aortic clamp, bypass, and total operation times were 119 (94-149), 166 (134-200) and 237 (204-285) min, respectively, median (25-75%). The 5-year survival and reoperation-free rates were 98.3% ± 0.9% and 96.9% ± 1.2%, respectively. CONCLUSIONS Three-port endoscopic MIMVS appears reproducible and safe.

Effect of modified proximal anastomosis of the free right internal thoracic artery: piggyback and foldback techniques

OBJECTIVES Few studies have reported the free right internal thoracic artery (RITA) being used in an aorto-coronary fashion. This study aimed to evaluate the free RITA with modified proximal anastomosis in an aorto-coronary fashion. METHODS Between January 2000 and December 2012, 282 patients underwent coronary artery bypass grafting with bilateral internal thoracic arteries for complete revascularization of the left coronary system at our institution. The left internal thoracic artery (LITA) was anastomosed to the left anterior descending artery (LAD) and the RITA was anastomosed to the left circumflex branches (LCX). The RITA was used as a free graft in 213 patients (free group) and as an in situ graft in 69 patients (in situ group). Proximal anastomosis of the free RITA onto the ascending aorta was performed in two different ways. We compared early and late results and graft patency of the free RITA with those of the in situ RITA retrospectively. RESULTS The numbers of anastomoses per patient and anastomoses of the RITA were larger in the free group than in the in situ group (P < 0.01). There was no significant difference in postoperative survival between the groups (free group: 93.3% vs in situ group: 90.0%, P = 0.82). The 5-year patency of the free RITA was higher than that of the in situ RITA (97.0 vs 80.3%, P = 0.01). The 5-year patency of the free RITA was comparable with that of the in situ LITA anastomosed to the LAD (97.0 vs 92.9%, P = 0.28). CONCLUSIONS The free RITA anastomosed to the LCX might have better late patency than the in situ RITA. The free RITA with modified proximal anastomosis in an aorto-coronary fashion enables complete revascularization of the left coronary system with the in situ LITA to the LAD.

Seamless reconstruction of mitral leaflet and chordae with one piece of pericardium.

OBJECTIVES Mitral valve repair is challenging when enough pliable mitral leaflets and chordae are not left intact because of extensive infective endocarditis or chronic sclerotic degeneration. For those cases, we developed a simple method to reconstruct defective leaflets and chordae en bloc with a piece of pericardium, and the mid-term results were evaluated. METHODS From January 2009 to November 2013, 25 patients with the mean age of 63 (range 20-88) years underwent this operation. The causes of mitral regurgitation were infective endocarditis in 8, sclerotic degeneration in 8, leaflet dehiscence of previous repair in 2, mitral annular calcification in 3, rheumatic in 2 and congenital in 2. After complete debridement of infected or consolidated tissue, we reconstructed defective mitral leaflets and chordae en bloc with a piece of glutaraldehyde-treated autologous pericardium. To substitute posterior leaflet and chordae, the pericardium was trimmed into a narrow pentagonal shape. The pointed end was attached directly to the corresponding papillary muscle, basal side edges to remnant leaflets on both sides, and the base to the annulus. For anterior leaflet, the pericardium was trimmed into a triangular shape if the lesion was confined in the left or right half or into a double-triangle shape if the lesion involved whole anterior leaflet. The summit of triangle was fixed to corresponding papillary muscle, and the base to remnant anterior leaflet, thus reconstructing coaptation zone and chordae seamlessly. RESULTS There was no hospital death, and mitral regurgitation at discharge was none or trivial in all patients. During 1-59 months (mean 12.7) of complete follow-up, death, infection or hemolysis was not observed. In one patient, mitral regurgitation recurred 8 months postoperatively because the fixation suture of the pericardium to the papillary muscle broke. The valve was re-repaired with re-attaching the leg of the pericardium. Regurgitation was less than moderate in all other patients. One patient with rheumatic lesion who underwent anterior leaflet repair and Maze operation suffered minor stroke 1 month postoperatively but fully recovered. CONCLUSIONS Seamless reconstruction of leaflets and chordae with pericardium seemed promising to repair extensively destructed mitral valve.

A Case of Constrictive Pericarditis after Minimally Invasive Mitral Valve Surgery Requiring Pericardiectomy

症例は 68 歳,男性.僧帽弁狭窄症,三尖弁閉鎖不全症,心房細動に対し僧帽弁置換術,三尖弁形成術, MAZE手術を内視鏡下右小開胸で施行した.特記すべき合併症なく第 7病日に退院となったが,退院後約 2 カ月が経過した頃より心嚢水貯留と右心不全症状を認め,利尿剤やステロイドなど内服加療を行ったがコン トロール困難で入院を繰り返した.CT検査や心臓超音波検査では特異的な所見は認めなかったが,心臓カ テーテル検査で dip and plateau patternを認めたため収縮性心膜炎と診断し,胸骨正中切開で心膜切除術を 施行した.心膜は皮革状の肥厚を認め,心外膜に強固に癒着していた.心膜切除により,術中から中心静脈 圧の低下に加え肉眼的にも右室収縮の改善を認めた.術後 1年現在経過良好である.心臓手術後の収縮性心 膜炎は稀な合併症であるが,特に低侵襲手術後の収縮性心膜炎の報告は過去になかったため,文献的考察を 加えて報告する.日心外会誌 47巻 5号:239-242(2018) キーワード:収縮性心膜炎;低侵襲心臓手術;心膜切除術

Trans-right axillary aortic valve replacement: propensity-matched comparison with standard sternotomy approach

OBJECTIVES We developed trans-right axillary aortic valve replacement (TAX-AVR) as a more cosmetically superior approach to minimally invasive AVR. We herein retrospectively compared the safety and invasiveness between TAX-AVR and conventional AVR (C-AVR). METHODS TAX-AVR was performed under femorofemoral cardiopulmonary bypass. Creation of a small right axillary vertical skin incision was followed by anterolateral intercostal thoracotomy. AVR was performed using long-shafted minimally invasive instruments, a knot pusher and endoscopic assistance. From January 2007 to June 2016, 112 patients underwent TAX-AVR and 183 controls underwent first-time, isolated non-emergency C-AVR. The factors used to calculate the European System for Cardiac Operative Risk Evaluation score and Society of Thoracic Surgeons score were adopted for propensity matching. Early mortality and major adverse cardiac and cerebral events were compared. The procedural time, postoperative intensive care unit stay and hospital stay were compared as markers of invasiveness. RESULTS Propensity matching generated 108 matched pairs with similar backgrounds. Thirty-day mortality occurred in 0 and 1 patient in the TAX-AVR and C-AVR groups, respectively. The major adverse cardiac and cerebral events rates were not significantly different between the groups. The average aortic clamp time was longer (100 vs 94 min), but the intensive care unit stay (1.2 vs 1.8 days) and hospital stay (10.0 vs 12.5 days) were shorter in the TAX-AVR group. Postoperative blood loss, transfusion and atrial fibrillation were lower in the TAX-AVR group. The average prosthesis size was 22 mm in both groups. CONCLUSIONS TAX-AVR is as safe as C-AVR and less invasive in terms of a shorter recovery period.