Vascular and Endovascular Surgery

Objectives and Background. Intraoperative transesophageal echocardiography (TEE) and epicardial echocardiography (ECE) offer the opportunity to assess valvular function before and after cardiopulmonary bypass. Valve reconstruction offers many advantages over prosthetic valve replacement. The purpose of this study was to assess the utility of TEE and ECE during the surgical treatment of mitral, aortic, and tricuspid valve diseases.

Methods. Intraoperative echocardiography was performed in 50 patients undergoing surgery for valvular heart disease. In 21 recent patients, concurrent TEE with Doppler color flow mapping was performed. The severity of mitral stenosis (MS) was assessed by the intraoperative echocardiographic mitral valve area (MVA) and morphologic findings of the mitral apparatus. The severity of mitral regurgitation (MR) was visually graded on a semiquantitative scale of 0-4+ according to the ratio of the maximal regurgitant jet area to the left atrial area (JA/LAA) indicated by transesophageal and epicardial Doppler color flow mapping. The severity of aortic regurgitation (AR) was similarly graded on a scale of 0-4+ according to the ratio of the maximal regurgitant jet area to the left ventricular area (JA/LVA) in end diastole. The severity of tricuspid regurgitation (TR) was similarly graded on a scale of 0-4+ according to the ratio of the maximal regurgitant jet area to the right atrial area (JA/RAA). These criteria for the severity of valvular regurgitation were compared with conventional nonsimultaneous angiographic criteria and operative criteria according to fluid injection into the flaccid ventricles. Tricuspid annulus diameter during systole was measured before and after tricuspid annuloplasty.

Results. There was a good correlation (r = 0.78, P < 0.001) between intraoperative two-dimensional echocardiographic MVA and operative MVA by direct measurement. Epicardial two-dimensional MVA and transthoracic MVA measured by mitral pressure half time method were similar (r = 0.88, P < 0.005). Mitral commissurotomy was performed in 4 (27%) of 15 patients with MS. Comparison of mitral JA/LAA measurements as assessed by epicardial and transesophageal color flow mapping revealed an excellent correlation between the techniques (r = 0.94, P < 0.001). Intraoperative TEE and ECE assessment of the severity of MR showed good agreement with preoperative angiographic gradings and with operative gradings. Mitral valve repair was performed in 10 (48%) of 21 patients with MR. Postrepair intraoperative Doppler studies showed satisfactory surgical results in all. No significant residual MR (grade > 2+) was identified in this series. Comparison of aortic JA/LVA measurements as assessed by epicardial and transesophageal color flow mapping showed an excellent correlation between the techniques (r = 0.96, P < 0.001). Intraoperative echocardiographic assessment of the severity of AR showed good correlation with preoperative angiographic assessment. Aortic valve repair was performed in 1 (11%) of 9 patients with AR. There was a good correlation (r = 0.77, P < 0.005) between tricuspid JA/RAA ratios as assessed by epicardial color flow mapping and operative gradings for TR. Tricuspid annulus diameter during systole measured by epicardial technique was significantly (P < 0.001) decreased after tricuspid annuloplasty.

Conclusions. Both intraoperative TEE and ECE are useful for the evaluation of valvular function in the mitral, aortic, and tricuspid positions. Doppler color flow mapping is a reliable method of assessing valve regurgitation. Combined intraoperative use of transesophageal and epicardial techniques is recommended.

The smooth muscle contractile properties of 100 human saphenous veins derived from healthy tissue and organ donors were investigated. No significant changes in the contractile responses of saphenous veins to potassium chloride, serotonin, and norepinephrine were associated with age. In contrast, comparison of contractile responses between males and females demonstrated significantly less response to potassium chloride in female veins (P<0.05). Female contractile responses to serotonin (P=0.74) and norepinephrine (P= 0.29) did not differ significantly when compared with male responses. These observations support the conclusion that gender may be an important variable in saphenous vein biology.

To investigate whether lipoprotein (a) (Lp[a]) is a risk factor for the development of carotid artery atheroma and restenosis after endarterectomy, 100 consecutive patients who had undergone endarterectomy were studied with repeat carotid Doppler ultrasonic scans to assess restenosis. The authors recorded history of vascular disease, medications, and smoking habits. Fasting samples were analyzed for serum total cholesterol, high-density lipoprotein cholesterol, triglycerides, apolipoprotein Al and B, urate, glucose, and Lp(a). Carotid artery stenosis was associated with higher levels of Lp(a) (390 ±40 vs 142 ±30 mg/L for controls, mean ±EM, P < 0.05), and concentrations were 45% higher (P < 0.05) in the 39 patients who had concomitant peripheral vascular disease. During follow-up (twenty-four to one hundred sixty-eight months) 23% of patients restenosed and the median time to restenosis was one hundred ten months. Cigarette smoking, hypertension, and previous myocardial infarction were weakly associated (P=0.1) with restenosis, but no association was found between Lp(a) levels and restenosis after endarterectomy.

Transvaginal Doppler ultrasound was applied to 85 patients to determine whether pelvic malignancy could be predicted by pulsatility (PI) and resistive indices (RI) of intratu-moral, ovarian, and uterine vessels. Thirty-five of the patients in the study were confirmed to have malignant tumors of the cervix, uterus, or ovary. The mean intratu-moral PI and RI from malignant tumors were 0.81 (SD 0.24; range 0.3-1.2) and 0.54 (SD 0.10; range 0.27-0.62), respectively. They were significantly lower than those of the benign group (both with P < 0.05, Student's t test). Thresholds of intratumoral PI < 1.0 and RI < 0.6, which differentiate malignant from benign tumors, were determined by using two receiver operating characteristic (ROC) curves. These gave a sensitivity of 94% and specificity of 63% for PI and a sensitivity of 71% and specificity of 63% for RI. The mean PI and RI from individual ovarian and uterine vessels were also significantly lower for the malignant group than those for the benign group. The authors conclude that PIs and RIs from intratumoral, ovarian, and uterine vessels are all useful in differentiating malignant tumors from benign ones, but universal thresh-olds for this purpose are far from determined. Also, comparison of intratumoral PI and RI showed that neither PI nor RI was statistically better than the other in malignancy prediction, because the areas under the two ROC curves were not statistically different (P > 0.2, chi-square method).

Background: The clinical efficacy of iloprost, a stable analogue of prostacyclin, in patients with Raynaud's phenomenon (RP) has been widely reported. However, its mechanism of action is still unclear, and also unknown is why the benefit lasts for many weeks after therapy is discontinued.

The aim of the present study was to learn what kind of microcirculatory changes occur in the skin of the affected hand one month after the end of iloprost treatment in patients with RP.

Patients and Methods: Eleven subjects (8 women, 3 men, mean age forty-four years) with RP suspected to be secondary to a collagen disease entered the study and were infused with iloprost up to 2.0 ng/kg/minute for six hours on five consecutive days. At baseline and one month after treatment discontinuation, laser Doppler flowmetry, thermography, and computer-assisted video capillaroscopy of the affected hand were performed.

Results: At the end of follow-up, the mean capillary density as recorded by video capillaroscopy was significantly increased as was the skin temperature in the different areas (fingertip, nailbed, tenar, hypotenar). In contrast, laser Doppler flowmetry revealed no significant changes after therapy.

Comment: The improvement of vascularization of the skin and, therefore, the decrease in avascular areas in patients with RP suspected to be secondary to a connective tissue disease appear to be associated with enhancement of nutritional flow. Rather than rely on an angiogenetic effect of iloprost, these modifications may be related to the drug-induced normalization of the described dysfunctional arteriolar-venular anastomoses in the skin of RP patients through redistribution of flow.

In order to study the possible mechanisms of atherosclerotic changes involving the saphenous vein graft in coronary bypass surgery, endothelial cells were cultured from human saphenous vein and used in experiments. The intimal surface of human saphenous vein was treated with collagenase followed by mechanical scraping with a surgical scalpel. The endothelial cells obtained were cultured in M 199 medium supplemented with 20% human serum. In experiments, different ambient pressures (either normal or increased at 100 mmHg) and oxygen tensions (either 20% or 5.3%) were applied to the cultured endothelial cells to study the effects on cell proliferation. Four experiments were performed. It was found that the growth rate of endothelial cells was constantly and significantly decreased in high ambient pressure. Increase in oxygen did not significantly affect cell growth. The culture condition closest to the venous environment rendered best cell growth. It is concluded that growth rate of cultured endothelial cells derived from human saphenous vein can be affected by changes in ambient pressure. The changes may play some role in the pathogenesis of bypass graft atherosclerosis.

Cor triatriatum dexter is a very rare cardiac malformation in which the right atrium is subdivided into two distinct chambers. The authors report the case of a three-day-old infant boy with body weight of 2.8 kg, severely symptomatic, with highly obstructive cor triatriatum dexter and patent foramen ovale. The malformation was diagnosed by two-dimensional echocardiography and corrected successfully by surgery.

The most characteristic pathophysiologic change in Buerger's disease or thromboangiitis obliterans (TAO) is considered the breakdown of microcirculation in the extremity, but this has not yet been proven. The purpose of this study is to examine the damage of microcirculation in TAO objectively, by means of intra-arterial injection of two kinds of radioisotope. In 7 TAO and 4 infrainguinal arteriosclerosis obliterans (ASO) patients, thallium 201 chloride (²⁰¹TI) and ^99mTc macroaggregated human serum albumin (^99mTc-MAA) were administered through bilateral common femoral artery injections. In the planar image of the foot, rectangular regions of interest (ROIs) were placed on the foot muscles and toes. Normalized counts of ^99mTc-MAA in each ROI were divided by that of ²⁰¹TI, and the result was defined as the microcirculation damage index, based on their different kinetics. The damage index of the foot muscle was not different between ASO and TAO, but that of the toe was lower in TAO than ASO patients. Lumbar sympathectomy was performed in 5 TAO patients, but it did not improve the damage index. It is concluded that there is breakdown of the microvascular defense system from the beginning of the disease, and critical ischemia make the regional cell function deteriorate as if a precursor to a trophic lesion. Lumbar sympathectomy did not immediately improve microcirculation.

A case of coronary artery-coronary sinus fistulae associated with a large hepatic hemangioma is presented. Aortography and coronary arteriography revealed a large left circumflex artery-coronary sinus fistula and a small right coronary artery-coronary sinus fistula. The left main trunk and left circumflex artery were markedly enlarged (3 cm in diameter), while the sizes of the left anterior descending and right coronary arteries were normal. Abdominal angiography and noninvasive imaging techniques demonstrated a huge hepatic hemangioma (8 cm in diameter) in the S5 region of the liver.

As intravenous drug abusers grow older, they develop a paucity of superficial veins for access, which compels them to guess at the location of deeper veins for access. On occasion, the drug is injected into an artery, resulting in limb-threatening ischemia.

Five patients (3 men/2 women) with an average age of 35.6 years (range twenty-eight to forty-three years) who inadvertently injected illicit drugs into an upper extremity artery developed a “trash-hand.” The injected drugs include crushed meperidine (2), crushed codeine (2), and crushed haloperidol (1). The patients initially treated with heparin alone (2) or dextran-40 alone (1) had progressive ischemia resulting in amputation of their hand. Patients initially treated with a combination of heparin and dextran-40 had limb salvage.

This small group of patients demonstrates that the combination of heparin and dextran-40 may be advantageous for treatment of patients with “trash-hand.”

A case of popliteal artery entrapment syndrome (PAES) with distal embolization is reported in a twenty-two-year-old man. PAES is caused by an abnormal relationship between vessels and muscle within the popliteal fossa. This syndrome is increasingly described as a cause of lower limb ischemia. Approximately 300 cases have been reported in the world literature. However, distal embolization to the leg and foot vessels is not emphasized. Also presented is a review of 7 other cases with distal embolization found in the literature.