Hiroshi Kumano

A New Procedure for Chronic Atrial Fibrillation: Bilateral Appendage-Preserving Maze Procedure

BACKGROUND Atrial transport and atrial natriuretic peptide secretion is severely reduced from normal after the maze III procedure. To improve these factors, we developed a bilateral appendage-preserving maze procedure (BAP-maze). METHODS Forty-six patients with chronic atrial fibrillation who underwent the BAP-maze procedure were compared with 40 patients who underwent the maze III procedure. The ratio of the peak velocity of the A and E waves of transmitral flow (transthoracic pulsed Doppler echocardiography), the left atrial appendage ejection fraction (transesophageal echocardiography), and the atrial natriuretic peptide secretory reserve during treadmill exercise test were measured at 6 months postoperatively. RESULTS Sinus rhythm was restored in 44 patients (95.7%) by the BAP-maze procedure and in 39 patients (97.5%) by the maze III procedure. The ratio of the peak velocity of the A and E waves was 0.52 +/- 0.22 in the BAP-maze group and 0.25 +/- 0.19 in the maze III group (p < 0.0001). The left atrial appendage ejection fraction was 44.7% +/- 11.5%, and the atrial natriuretic peptide secretory reserve was greater in the BAP maze group (p = 0.037). CONCLUSIONS The BAP-maze procedure improved atrial transport and atrial natriuretic peptide secretion as well as simplifying the maze operation, without decreasing its effectiveness against atrial fibrillation.

Coagulofibrinolysis during heparin-coated cardiopulmonary bypass with reduced heparinization

BACKGROUND We examined the safety of reduced systemic heparinization during heparin-coated cardiopulmonary bypass by measuring coagulofibrinolitic indices, including fibrinopeptide A, which directly reflects fibrinogenesis. METHODS Twenty-four patients who had elective cardiac operations were perfused using a circuit coated with covalently bonded heparin. Twelve patients received 300 U/kg of heparin and the remaining 12 patients received 150 U/kg. Blood was obtained for the measurement of thrombin-antithrombin III complexes, fibrinopeptide A, plasmin-alpha 2 plasmin inhibitor complexes, and D-dimer preoperatively; after heparin administration; 10, 60, and 90 minutes after the start of bypass; after protamine administration; and 1, 3, 6, 12, and 24 hours after the end of bypass. RESULTS Preoperative, intraoperative, and postoperative variables including postoperative bleeding were not significantly different between the two groups. Further, there were no complications in either group. No significant differences between the two groups were noted for any hematologic index at any time point. CONCLUSIONS Reduced systemic heparinization combined with a heparin-coated cardiopulmonary bypass circuit is biochemically and clinically safe but does not reduce postoperative bleeding.

Duplex scanning to assess radial artery suitability for coronary artery bypass grafting.

OBJECTIVE Radial artery suitability in coronary artery bypass grafting was assessed using duplex ultrasonography. SUBJECTS AND METHODS The vascular condition along the entire radial artery was scanned in 55 patients, measuring the internal diameter and mean flow velocity at the wrist (distally), after ulnar artery branching (proximally), and midway between these 2 points (medially). Distally along the radial and ulnar arteries, the mean flow velocity was determined before and after radial artery occlusion. RESULTS Atherosclerotic changes were detected in 4 patients. The internal diameter was 3.1 +/- 0.4 mm proximally, 2.7 +/- 0.3 mm medially, 2.4 +/- 0.4 mm distally. The distal flow velocity was 0, and a reverse flow (peak velocity: 11.3 +/- 6.0 cm/s) was observed after the occlusion test in patients with an intact palmar arch, their mean flow velocity, 21.1 +/- 8.9 cm/s, and flow distally along the ulnar artery 58.0 +/- 23.4 ml/min, were higher after the occlusion test than before it 14.7 +/- 6.7 cm/s mean flow and 38.1 +/- 15.9 ml/min distally. This was not observed in patients with an interrupted palmar arch. In 15 patients, radial arteries could not be used because of their small internal diameter, lack of a radial artery, poor vascular condition, or an interrupted palmar arch evaluated using duplex scanning. CONCLUSION Reliable noninvasive assessment of radial artery anatomy and palmar arch continuity is thus possible using duplex ultrasonography.

Secondary mitral valve replacement in antiphospholipid syndrome and chronic renal failure.

A 48-year-old woman admitted with progressive dyspnea had previously been diagnosed with systemic lupus erythematosus, antiphospholipid syndrome, and chronic renal failure, and had undergone mitral valve replacement with a Carpentier-Edwards pericardial bioprosthesis for mitral insufficiency 9 years before. She suffered a cerebral infarction 5 years earlier, despite appropriate anticoagulant therapy. On admission, echocardiography showed severe bioprosthetic stenosis. Repeat mitral valve replacement was conducted using a Mosaic bioprosthesis. On postoperative day 2, when heparinization was commenced, she suddenly had an epileptic fit. She also developed ischemic necrosis of the fingers and toes, considered secondary to microthrombosis. Aspirin was administered and heparin replaced by warfarin sodium. Necrosis gradually disappeared, and she was discharged 3 months after surgery. The original bioprosthesis showed degenerative changes with significant thrombus formation on cusps, thought to be mainly due to her hypercoagulable state. Considering the thrombophilic tendency in patients with antiphospholipid syndrome, strict management of anticoagulant therapy is required.

Use of a vascular closure system for bypass grafting of peripheral arteries

Vascular anastomosis is generally done by the needle-and-suture technique. Recently, a vascular closure system (VCS) with nonpenetrating clips was developed. Its use for patients with arteriosclerosis obliterans has not been reported yet. Sixteen anastomoses in seven consecutive patients were done with VCS clips. All anastomoses were end-to-side with expanded polytetrafluoroethylene grafts. Use of the clips was abandoned intraoperatively at five anastomotic sites because the arterial walls were not pliable and because of thickness or calcification. These sites were anastomosed by the conventional needle-and-suture method. Anastomosis took a mean of 10 minutes. Anastomotic rupture, bleeding from the joined edge, and acute occlusion of the graft did not occur. The patency of all grafts was excellent 6 months after surgery. The system seemed to be useful and easy to handle.

Mitral insufficiency associated with primary antiphospholipid syndrome and chronic renal failure.

We report a case of 52-year-old woman with primary antiphospholipid syndrome who developed mitral insufficiency and chronic renal failure. Continuous ambulatory peritoneal dialysis was started preoperatively due to thrombocytopenia that was aggravated by hemodialysis. Mitral annuloplasty was performed since the mitral valve was not severely damaged. Her postoperative hemodynamics were stable, and anticoagulant therapy was controlled easily. She recovered from severe thrombocytopenia while on continuous ambulatory peritoneal dialysis. Valvular heart disease is a well known feature of primary antiphospholipid syndrome, and there have been several reports about valve replacement in patients who had antiphospholipid syndrome with or without systemic lupus erythematosus. However, valve repair has been reported in only a few such patients. We believe that valve repair is better than valve replacement in patients with antiphospholipid syndrome because of its hypercoagulable tendency. In addition, it seems that continuous ambulatory peritoneal dialysis is a suitable method for the perioperative management of patients with antiphospholipid syndrome who suffer from chronic renal failure as well as thrombocytopenia, and require cardiac surgery under cardiopulmonary bypass.

Blunt traumatic rupture of right ventricle and pericardium

A 60-year-old man was transferred to our hospital for blunt trauma of the chest suffered in a traffic accident. He had a weak pulse, and cardiopulmonary resuscitation was continued in the ambulance. Chest roentgenography revealed left hemothorax, and echocardiography revealed pericardial bleeding. He was immediately transported to the operating room, because of severe hypotension due to massive bleeding from the chest drainage tube. Median sternotomy was performed under stand-by cardiopulmonary bypass. There was projectile bleeding from the anterior wall of the right ventricle. The site of rupture was sutured with felt strip. A tear in the pericardium was also present at the apex. Postoperative recovery was uneventful. Fulda et al. reported that the incidence of combined pericadial and cardiac chamber rupture was 8% for those patients suffering blunt chest trauma, and that the rate of survival was less than 15% for blunt heart rupture. We have reported here successful repair of combined rupture of the right ventricle and pericardium.

Beneficial Effects of Preoperative Coronary Angiography and Coronary Artery Revascularization in Patients Undergoing Surgery for Abdominal Aortic Aneurysm

待機的腹部大動脈瘤 (AAA) 症例に対する術前冠動脈造影 (CAG) と冠血行再建術の有用性を検討した. 1995年1月から1999年11月までの待機的AAA手術53例に術前 routine CAG施行したところ, 23例 (43%) に有意冠動脈狭窄を認め, さらに無症候性心筋虚血を10例 (19%) に認めた. 冠動脈狭窄を有するものには, 負荷心筋シンチを行い, 術前冠血行再建の適応を判断した. 虚血性心疾患合併例の12例に対してCABG 4例, PTCA 8例の術前冠血行再建を施行した. CABGとPTCAによる死亡はなかった. AAA手術死亡を1例 (2%) のみに認め, 原因は腸閉塞より多臓器不全合併による死亡であった. その他, CADに起因する合併症はみられなかった. 以上のことより, 待機的AAA症例では全例にCAGを施行し, 周術期心筋梗塞の合併が危惧される症例には術前冠血行再建を施行することが, 重要であると考えられた.

A Case of Rheumatic Tricuspid Stenosis 22 Years after Initial Mitral Valve Replacement.

リウマチ性三尖弁狭窄症 (TS) は最近では比較的希である. 今回われわれは, 僧帽弁狭窄症 (MS) に対する初回僧帽弁置換術 (MVR) の22年後に発症した三尖弁狭窄兼閉鎖不全症 (TSR) に対して単独三尖弁置換術 (TVR) を施した1例を経験したので報告する. 症例は54歳, 女性. 32歳時MSに対しMVR (Carpentier-Edwards 29mm) を施行. 42歳時人工弁機能不全のため再MVR (Duromedics 27mm) を施行. 1998年5月著明な下半身浮腫が出現した. 心臓カテーテル検査上肺高血圧を認め, 右房右室拡張期最大圧較差は6mmHgであり, TVR (Hancock-II 29mm) を施し, 術後浮腫は著明に改善した. 三尖弁の器質的変化がみられ, かつ肺高血圧を合併している場合TSを発症する素因があると考えられ注意深い経過観察が必要であると思われた.