Chien-Tai Lu

Indications, surgical technique, and long-term functional results of colon interposition or bypass.

Over a 17-year period, 92 patients with esophagcal disease underwent colon interposition or bypass, with each operation performed by the same surgeon. The indication was cure of cancer in 20 patients, relief of dysphagia in 55 (cancer in 17 patients and benign in 38), loss of gastrointestinal (G.I.) continuity in ten, and tracheoesophageal fistula in seven patients (malignant in five, benign in 2). The thirty-day operative mortality rate was 5%, and the hospital mortality rate was 9%. Graft necrosis occurred in seven of 92 patients, four of whom later underwent a successful second reconstruction. Thirteen patients required subsequent revisional surgery. In 85 patients, the left colon based on the inferior mesenteric artery was used, and in seven, the right colon was used. Technical insights were gained to help preserve the blood supply to the graft and improve its function in transporting food. Thirty-four patients were available for interview 2–17 years after operation (median of 5 years) 28 of whom had benign disease, and six of whom had malignant disease); 82% of the patients felt they were cured of their preoperative symptoms, 18% improved, and none worsened. Eightyeight per cent of the patients were able to receive an unrestricted diet. All patients except one were satisfied with the results of surgery, and, asked what they would do if they had to make the choice again, all responded that they would have the operation. Twenty-six of the interviewed patients had their eating ability evaluated with a test meal and the transit time of a liquid and solid barium bolus measured. Compared to controls, patients with colon interpositions consumed a smaller capacity meal over a longer period of time and were not dependent on liquids to flush the food through the colon graft. A colon interposition provides good quality of deglutition, is very durable, and is the organ of choice for patients who require an esophagcal substitute and are potential candidates for long survival.

Percutaneous transluminal angioplasty versus surgery for limb-threatening ischemia

This retrospective study compared the results of percutaneous transluminal angioplasty (PTA) with those of infrainguinal bypass procedures in patients with critical arterial ischemia to determine which procedure had superior patency, limb salvage, and durability. The records of 54 patients who underwent 54 PTAs and 56 patients who underwent 63 infrainguinal bypasses (29 femoropopliteal and 34 femorodistal) from 1981 to 1987 were reviewed. In each patient PTA or bypass was the initial vascular procedure. Patients in both groups were comparable with respect to age, sex, and the presence of diabetes, hypertension, obesity, hypercholesterolemia, and smoking. Mean follow-up was 40 months (4 to 88 months) for the PTA group and 28 months (6 to 78 months) for the surgery group. Thirty-nine of the 54 patients (72%) were initially improved after PTA, whereas 15 patients (28%) showed no improvement. During follow-up, 20 initially successful PTAs reoccluded. Thirty-two of 54 patients (59%) underwent subsequent procedures, which included repeat PTA (10) and distal bypass (14). Patency determined by noninvasive Doppler studies was 18% at 2 years. Limb salvage, which included such secondary procedures, was 78%. Two-year patency for femoropopliteal bypasses was 68% with a limb salvage of 90%. Femorodistal bypasses had a 2-year patency of 47% and a limb salvage of 74%. No perioperative deaths occurred. Twenty-one of the 63 patients (33%) had subsequent procedures, which included thrombectomy (5) and bypass revision (9). In patients treated for limb-threatening ischemia the 2-year patency after femoropopliteal bypass (68%) or femorodistal bypass (47%) is significantly better than that from PTA (18%, p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Vessel, plaque, and lumen morphology after transluminal balloon angioplasty. Quantitative study in distended human arteries.

We performed transluminal balloon angioplasty In 24 cadaver and nine amputated limb superficial femoral arteries under controlled experimental conditions. The cadaver arteries were excised, restored to in situ length, redistended, and maintained at 100 mm Hg Intraluminal pressure at 37° C throughout the anglographlc and dilation procedure and during fixation. The amputated limb arteries were dilated and pressure perfusion-flxed after dilation. Quantitative analysis of cadaver vessels revealed that arteries with prominent atherosclerotic lesions had the same internal elastic lamina (IEL) circumference (15.6 ± 1.0 mm) as those with little or no stenosis (16.8 ± 0.5 mm) but lumen area (8.8 ±1. 7 mm2) was markedly reduced compared to nonstenotlc sites (20.0 ± 1.9 mm2, p < 0.01). Lesions occupied 49 ± 6% of the area circumscribed by the IEL In cadaver arteries with prominent plaques. After dilatation, lumen areas at stenotic sites were enlarged 43% on hlstologic sections (12.6 ± 1.8 mm2 vs 8.8 ±1. 7 mm2, p < 0.01) and 31% as determined by anglography (p < 0.05) when compared to Immediately adjacent nondilated regions. The Increased lumen area was associated with splitting of the Intlma near the edges of the plaque, separation of the edges of the plaque from the media, and stretching of the media and adventltla, often with accompanying rupture of the media. There was no evidence of plaque compression, fragmentation, deformation, modeling, or hernlatlon Into the media. The detached wedgeshaped edges of the lesions formed flaps projecting Into the lumen, resulting in a marked increase in lumen Irregularity on cross-section. Dilatation of clinically significant stenoses and completely occluded arteries was accomplished by the same mechanism with fracture of the plaque, separation of the plaque from the underlying artery wall and stretching of the artery wall to create or enlarge the artery lumen.

Increased collagenase activity in early aneurysmal dilatation

Increased collagenase activity has been implicated as a basic abnormality in aortic aneurysm formation. We studied a localized aneurysmal change, poststenotic dilatation, and its relation to collagenase and elastase activity of the aortic wall. Cynomolgus monkeys underwent midthoracic aortic coarctation to produce poststenotic dilatation. Serial angiography showed that poststenotic dilatation was minimal or absent at 10 days, just discernible at 3 months, and prominent at 6 months. At the 3-month time interval, collagenase activity in the region of the poststenotic dilatation increased twofold compared with the same region in aortas from animals without poststenotic dilatation (p less than 0.05). There was no change in aortic elastase activity. These data indicate that collagenolysis and aneurysmal dilatation may be induced by local modifications of pressure and/or flow. Increased collagenase activity associated with abdominal aortic aneurysms may not represent an intrinsic metabolic defect but rather a response to altered hemodynamic conditions.

The role of transluminal angioplasty in limb salvage and claudication

With the introduction of the Griintzig balloon catheter, percutaneous transluminal angioplasty has gained increased acceptance and has been used to dilate lesions in the coronary [7], renal [6, 91, mesenteric [41, aorta [5], iliac [ 11, femoral [3] and popliteal [3] arteries. In lower extremity ischemia it has been used primarily to treat patients with claudication and short segmental lesions [8] with relatively poor success in limb salvage situations with long segment obstruction and poor runoff [8, 121. Because of a high initial success rate and low complication rate [8], the procedure has been used, at times, in patients with minimal symptoms who otherwise would not be considered for operation. However, objective documentation of the results of transluminal angioplasty and long-term follow-up have been lacking. In order to evaluate the procedure and help develop proper patient selection criteria, we recorded lower extremity systolic blood pressure indices before and after transluminal angioplasty in two groups of patients who were not candidates for operative revascularization. In one group were patients with claudication who had surgically correctable lesions, but did not undergo operation because they declined operation or were felt to have symptoms that were not severe enough to warrant operation. In the other group