Kazutomo Goh

Role of infrainguinal bypass in Buerger's disease: An eighteen-year experience

OBJECTIVES The role of bypass to the distal arteries for patients with Buergers disease (thromboangiitis or TAO) remains controversial because of the high incidence of graft failure. We retrospectively reviewed the results of 71 bypasses to evaluate their efficacy. MATERIALS AND METHODS We performed 71 autogenous vein bypasses in 61 patients with TAO. Of the patients, 97% were heavy smokers. The indications for surgery were claudication in 41%, and ischaemic ulcer or gangrene in 59%. Of the bypasses 85% were to the crural arteries or to the arteries below the ankle. The grafts used were 53 single saphenous veins, and 18 venovenous composite grafts. RESULTS There were 38 graft failures, the main causes including anastomosis to a diseased artery, disease progression (which occurred in smokers after surgery), and vein graft stenosis. Of 38, 10 were restored to patency by revision surgery. Primary and secondary patency rates were 48.8% and 62.5% at 5 years, and 43.0% and 56.3% at 10 years, respectively. The patency rates of the postoperative non-smoking group was significantly higher than that of the smoking group (66.8% vs. 34.7%, p < 0.05). Thirty-six patients (59%) had successful revascularisation and returned to full-time work. However, of 28 with secondary failure, 11 underwent amputation, while 14 had persistent disabling claudication. CONCLUSION Bypass to the distal arteries is an effective treatment for TAO patients, and the long-term patency is quite satisfactory as long as patients stop smoking.

PLANTAR OR DORSALIS PEDIS ARTERY BYPASS IN BUERGER'S DISEASE

The peripheral type of Buergers disease is unresponsive to conservative therapy when accompanied by multisegmental occlusion at the level of the ankle. Between November 1983 and April 1993, we performed 15 bypasses below the ankle for this type of thromboangiitis obliterans in 13 patients (mean age 45.7 years), including four females. Ten patients had intractable toe ulcers with severe pain, and five had foot-threatening ischemia or disabling foot claudication. Eleven patients were heavy smokers, two were passive smokers, and six had a history of sympathectomy. All patients had occlusion of the three main crural arteries or both of the tibial arteries at the ankle. Of the 15 bypasses, 10 were to the medial or lateral plantar arteries, two were to the common plantar artery, and three were to the dorsalis pedis artery. There were three early and three late graft failures. The causes of early graft failure were thrombosis at the site of cross-clamping, anastomosis to a diseased segment, and arterial spasm. The three late failures (>3 months) were due to disease progression in patients who continued to smoke, whereas all grafts remained patent and functioned well in patients who stopped smoking. Because patients with thromboangiitis obliterans are relatively young and active, early healing of ulcers and restoration of normal limb function are important objectives in their treatment. Bypass to the foot arteries can provide an excellent outcome, although special techniques and postoperative cessation of smoking are essential for success.

Isolated Iliac Artery Aneurysm Caused by Fibromuscular Dysplasia: Report of a Case

Fibromuscular dysplasia (FMD) can develop in many different arteries, but iliac artery aneurysms are rare. A 69-year-old Japanese woman was admitted to our hospital for treatment of a right common iliac artery aneurysm. Aortography revealed aneurysms in both the right common iliac artery and the left internal iliac artery. Notably, the right common iliac artery aneurysm had a “string-of-beads” appearance. At surgery, the aneurysms were resected, and replaced with Y-shaped vascular prostheses. The histopathological diagnosis was fibromuscular dysplasia (FMD). We report this case of common iliac artery aneurysm caused by FMD due to its rarity.

Early results of a reinforced biosynthetic ovine collagen vascular prosthesis for small arterial reconstruction

The efficacy of a reinforced biosynthetic ovine collagen (RBOC) vascular prosthesis developed for small arterial reconstruction was assessed by examining 30 grafts in 29 patients with arteriosclerosis obliterans. The operative procedures performed were femorofemoral bypass in 2 patients, above-knee femoropopliteal bypass in 28 patients, and below-knee femoropopliteal bypass in 1 patient. Femoropopliteal bypass was simultaneously performed in two patients undergoing femorofemoral bypass using one or two grafts. The indications for surgery were intermittent claudication in 27 patients and to salvage the limb in 2 patients. The longest follow-up period was 49 months, and there were six graft failures, occurring 1, 1, 9, 17, 17, and 23 months after implantation, respectively; caused by compression of the graft from outside in two, infection in one, anastomotic intimal hyperplasia in one, and unknown factors in two. Thus, the primary cumulative patency rate for above-knee femoropopliteal bypass at 3 years was 83.7%, and the secondary patency rate was 91.2%. No aneurysmal change was observed. Moreover, the RBOC was able to be used without preclotting, and its handling and suturing characteristics were satisfactory. Our findings suggest that this vascular prosthesis may be an acceptable alternative for above-knee femoropopliteal bypass.

Isolated Right Ventricular Hypoplasia: Intraoperative Balloon Occlusion Test

A 42-year-old woman with isolated right ventricular hypoplasia underwent operation. To determine the optimal procedure, we temporarily occluded the atrial septal defect with a balloon catheter that was introduced through the right atrial appendage. The hemodynamics were stable throughout the occlusion test. Simple closure of the atrial septal defect was safely accomplished. Intraoperative occlusion test with the balloon catheter was a good alternative to preoperative occlusion test.

Konno procedure for infective endocarditis involving aortic valve in a small child

The Konno procedure was performed to replace the aortic valve and the sinus of Valsalva in a 1-year-old child with pneumococcal infective endocarditis. A Dacron (C.R. Bard, Haverhill, PA) graft and a 16 AP ATS Medical valve (ATS Medical Inc, Minneapolis, MN) were used. Adequate debridement could be easily performed. Postoperative recovery was uneventful. The procedure, originally developed for a narrow aortic annulus, could be a good option for the treatment of a small child with aortic valve endocarditis.

Vascular clamp for hemostasis and stabilization during minimally invasive direct coronary artery bypass

A soft vascular clamp was used for hemostasis and stabilization of the operative field during minimally invasive direct coronary artery bypass (MIDCAB). The instrument was gently applied so that it clamps the coronary artery by grasping the adjacent myocardium. The method offered dry and stable operative field without a special instrument or technique. The surgical results have been satisfactory. We found application of the vascular clamp to be very helpful for MIDCAB.

Tube device for facilitating distal anastomosis in aortic arch replacement

The technique of placing an inverted graft into the descending thoracic aorta facilitates and secures the distal anastomosis in aortic arch replacement, especially in the anastomosis beyond the transverse arch. We developed a simple technique using a pair of thin-walled tubes to enable the arch graft, with its four branches, to be smoothly inserted into the flaccid, normal-caliber descending aorta. The use of these tubes simplified the procedure, resulting in time saving.

Role of medial smooth muscle cell function in antithrombogenicity of vein grafts

OBJECTIVES To determine the significance of prostaglandin I2 (PGI2) production by medial smooth muscle cells (SMCs), we assessed PGI2 production from denuded vein grafts and their antithrombogenicity. MATERIALS AND METHODS A total of 30 dogs were divided into two groups: in group I, 14 dogs (27 veins, 188 segments) were used to assay PGI2 production, which was measured as 6-keto-PGF1 alpha. In group II, 16 dogs were used for an implantation study and the thrombus-free surface (TFS) score was calculated 24 h after implantation. Both groups contained the following subgroups: subgroup A, freshly harvested veins; subgroup B, endothelial denuded veins; subgroup C, veins frozen and cryopreserved; subgroup D, veins treated with protease. RESULTS Values of 6-keto-PGF1 alpha (pg/mg/min) for basal and stimulated states in subgroup I-A through I-D were 58.0 +/- 8.9 and 530.6 +/- 74.7, 26.3 +/- 4.7 and 82.3 +/- 11.4, 17.9 +/- 1.3 and 39.4 +/- 3.3, and 13.3 +/- 1.8 and 32.2 +/- 6.2, respectively. The PGI2 production in subgroup I-A were significantly higher than those in the other three subgroups (p < 0.01 for basal and stimulated), while the production in subgroup I-B was also significantly higher than those in the remaining two (p < 0.05 for basal and stimulated). The TFS scores in subgroup II-A through II-D were 98 +/- 2%, 90 +/- 2%, 38 +/- 5%, and 15 +/- 7%, respectively, showing significantly superior antithrombogenicity in subgroup II-B, as well as in II-A, when compared with the remaining two (p = 0.014). CONCLUSION The amount of PGI2 generated by the medial SMCs may be sufficient for maintaining the antithrombogenicity of the endothelial denuded AVGs.

Blood Cardioplegia Serves as a Bicarbonate Donor to the Myocardium during Ischemia: Effects of Anoxia and Hypercapnia on Acid-Base Characteristics of Blood Cardioplegic Solution

Objectives: We investigated the alterations of acid-base characteristics of the blood cardioplegia (BCP) solution during aortic cross-clamping in hearts arrested with BCP and during in vitro-simulated ischemia. Methods: Following aortic cross-clamping, the hearts of 40 patients undergoing cardiac surgery were intermittently infused with an 18°C BCP solution and finally with a 34°C BCP solution prior to aortic cross-clamp release. We measured the pH, partial CO₂ pressure (pCO₂), [HCO₃^–], and [Cl^–] of the coronary sinus effluent in the final BCP solution. The BCP solution was assessed under in vitro gassing at 34°C with 95% N₂ + 5% CO₂ (n = 6), 50% N₂ + 50% CO₂ (n = 3), or 100% CO₂ (n = 6). Results: The coronary sinus effluent, compared with the preinfusion BCP solution, exhibited a significantly lower pH and a greater pCO₂ with no change in the [HCO₃^–] level. In vitro, the 95% N₂ + 5% CO₂ gassing (simulated hypoxia) group exhibited a slight increase in [HCO₃^–] with no change in pCO₂ or pH whereas the 50% N₂ + 50% CO₂ gassing and the 100% CO₂ gassing (simulated hypoxia and hypercapnia) groups exhibited a significant increase in [HCO₃^–] under high pCO₂-induced acidification. Conclusions: Under anoxia and CO₂ retention during aortic cross-clamping, the BCP solution can be a bicarbonate donor to the myocardium.