Internal carotid artery pseudoaneurysm related to pregnancy.

Arterial rupture is a common cause of maternal death. The increased tendency of true and false aneurysms to develop or rupture with advancing gestational age suggests that hemodynamic, hormonal, or other physiologic changes of pregnancy may play a role in their formation. To our knowledge, pseudoaneurysm formation from a carotid dissection or a ruptured true aneurysm related to pregnancy has not been previously reported. We report the successful repair of a large extracranial internal carotid artery pseudoaneurysm related to pregnancy. The clinical presentation, diagnostic modalities, surgical exposure, and treatment options for high internal carotid artery aneurysms will be discussed.

May-Thurner syndrome: a previously unreported variant.

Irritation of the left common iliac vein by the overlying right common iliac artery may result in intraluminal obstruction and symptomatic venous occlusion of the left lower extremity. We recently treated a 39-year-old patient with such an obstruction of the left common iliac vein as a result of compression by the left internal iliac artery. This case stresses the need to consider etiologies of external venous obstruction of the left lower extremity other than the commonly reported right common iliac artery when planning surgical intervention.

Replacement of the abdominal aorta with an aortic homograft in a patient with an aortic dissection.

The use of aortic and femoral homografts in early vascular surgery has been abandoned for the more successful and abundant synthetic substitutes. With the recent introduction of cryopreservation, homograft use has again met with improved success. A 40-year-old man who had a DeBakey Type I aortic dissection initially underwent replacement of the aortic root with a pulmonary homograft. Subsequently, in the presence of an intraabdominal infectious process, progressive mesenteric and lower limb ischemia was treated by replacing the abdominal aorta with an aortic homograft. Thirty-six months postoperative the patient has a functioning gastrointestinal tract and no vascular insufficiency of the lower extremities and no evidence of degeneration of the homograft. Further laboratory studies should be undertaken using the newer and improved cyropreserved homograft in the presence of, or potential for, an intraabdominal infectious process.

Thrombolytic therapy in acute arterial thrombosis.

The courses of 17 patients who underwent 20 separate attempts at thrombolysis for acute arterial thrombosis are reviewed to clarify the safety and efficacy of this therapy. Seventeen of 20 thrombolyses were angiographically successful. Patients who had correctable lesions identified and reconstructive procedures performed tended to do better than those who did not, and patients who had successful thrombolysis tended to have fewer and less radical amputations. Complications can be reduced by careful, close monitoring of patients undergoing therapy.

Acute aortic occlusion.

Acute aortic occlusion is a rare and emergent vascular event. Patients who present with this disorder have a classical history and physical examination consistent with occlusion of the distal aorta and resultant ischemia to the distal tissues. Time is of the essence in dealing with these patients. Aortography proved to be important in determining renal artery involvement in our patients. Based on this finding, we suggest that preoperative arteriograms be obtained. The method of treating these patients after arteriography should be to move quickly to the operating room. Patients with renal artery occlusion must be seriously considered for primary revascularization with either aortofemoral or aortoiliac reconstruction and thrombectomy or bypass of the occluded renal artery. If no renal artery involvement is revealed on arteriography, the initial operation should include an attempt to reestablish inflow by retrograde femoral thromboembolectomy under local anesthesia. If that fails, a decision must be made based on the patient's clinical status, whether a major vascular procedure would be tolerated. If so, primary revascularization or transabdominal thrombectomy should be attempted. If the patient is deemed unable to tolerate a major vascular procedure, then axillobifemoral bypass under local anesthesia should be performed. Postoperatively, the patient should be aggressively managed to prevent pulmonary and renal complications. Even with aggressive surgical management and postoperative care, these patients have an uncertain postoperative course. It is of primary importance that physicians realize that time is a critical factor and these patients must be referred to the appropriate care center promptly. Only by ensuring prompt surgical management can a mortality rate of less than 50 percent be expected.

Preoperative coronary artery bypass grafting in patients undergoing abdominal aortic reconstruction.

The effect of preoperative aortocoronary bypass grafting on the operative mortality of patients undergoing elective abdominal aortic reconstruction was examined by reviewing a series of 224 consecutive patients (1980 to 1983) (Group I) in whom selective preoperative noninvasive and invasive cardiac screening was used to identify patients with significant coronary stenoses. One patient died during cardiac catheterization. Twenty-seven patients (12 percent) underwent aortocoronary bypass grafting with one operative death (3.7 percent) and one nonfatal myocardial infarction (3.7 percent). These 26 patients subsequently underwent abdominal aortic reconstruction with no mortality and no postoperative myocardial infarction. One hundred ninety-six patients (88 percent) underwent aortic reconstruction without prior aortocoronary bypass grafting with four operative deaths (2 percent), including two fatal myocardial infarctions. The combined operative mortality for Group I patients was 2.3 percent. Three hundred twenty-six patients (Group II) who underwent abdominal aortic reconstruction at this institution from 1970 to 1976 had an 8 percent operative mortality, of which 50 percent of the deaths were due to myocardial infarctions (Group I versus Group II, p less than 0.01). Selective preoperative screening for coronary artery disease in patients undergoing elective abdominal aortic reconstruction with aortocoronary bypass grafting in selected patients is safe and may help reduce the operative mortality.

Difficulties in the diagnosis and treatment of pancreas divisum.

The anatomic variant pancreas divisum has been implicated as possibly playing a role in the development of idiopathic pancreatitis. A number of recent reports have supported the use of sphincteroplasty of the minor ampulla to treat pancreatitis associated with pancreas divisum. We reviewed the cases of five recent patients with this anomaly who had problems or complications associated with the operative treatment of their pancreatitis. One patient was subsequently found to have adenocarcinoma of the pancreas after pancreatic resection; one patient had restenosis of the minor ampulla; one patient had recurrent pancreatitis following sphincteroplasty; one patient died of pancreatic necrosis postoperatively; and in one patient, no minor ampulla could be identified. Awareness of these complications and the technique of sphincteroplasty are of critical importance to the surgeons caring for these patients.

Global and regional function in the regionally ischaemic left ventricle related to plasma ionised calcium.

To study the response of function in the regionally ischaemic left ventricle to increased and decreased concentrations of plasma ionised calcium, twenty-two anaesthetised dogs were placed on right heart bypass with constant mean aortic pressure and heart rate. Regional (sonomicrometry) and global left ventricular function were assessed before coronary artery ligation. Then, following ligation, function after 45 min stable ionised hypercalcaemia [( Ca2+] = 1.68 +/- 0.01 mmol x litre-1) and hypocalcaemia [( Ca2+] = 0.73 +/- 0.02 mmol x litre-1) were each compared to function during an immediately preceding normocalcaemic period. Control of cardiac output enabled paired comparisons to be made at matched preloads: systolic shortening from common end-diastolic chord lengths (n = 10), and stroke work at common left ventricular end-diastolic pressures (n = 22). With hypercalcaemia, systolic shortening in the ischaemic region (2.11 +/- 0.39 mm preligation) increased from -0.62 +/- 0.17 to -0.04 +/- 0.20 mm (P less than 0.01), whereas in the control region systolic shortening increased from 1.47 +/- 0.12 to 2.00 +/- 0.15 mm (P less than 0.01) reaching its preligation value (1.67 +/- 0.13 mm). Stroke work at a left ventricular end-diastolic pressure of 1.37 kPa increased (0.248 +/- 0.019 to 0.299 +/- 0.021 joules x beat-1, P less than 0.001) but not to preligation levels (0.364 +/- 0.016 joules x beat-1). Hypercalcaemia also increased myocardial oxygen consumption (by 1.0 +/- 0.3 cm3 x min-1 x 100 g-1, P less than 0.005) but not coronary blood flow. With hypocalcaemia, systolic shortening decreased in ischaemic and control regions, global function curves were markedly depressed, and myocardial oxygen consumption did not change but coronary blood flow increased. Thus hypercalcaemia improved function in ischaemic and control regions but improvement in the ischaemic region was small compared with the depression associated with ischaemia itself. Hypercalcaemia also improved global function, but not to preischaemic levels, at an increased oxygen cost.

Inability of seven-pinhole myocardial tomography to obtain accurate 201Tl kinetic data.

Seven-pinhole myocardial tomography has been reported to enhance the accuracy of thallium-201 (201Tl) studies in detecting patients with coronary artery disease. To determine if this approach can accurately assess regional 201Tl kinetics, 12 dogs with temporary occlusion (mean 15 min) of either the left anterior descending (LAD) (n = 6) or left circumflex (LCX) (n = 6) coronary artery were studied. Thallium-201 was injected and serial 7-pinhole images were acquired during occlusion and following reflow (mean duration 175 min). Time-activity analysis was obtained from normal and ischemic regions of interest in the central pinhole image and the reconstructed tomographic images (TOMO-ROI). Time-activity data from corresponding normal and ischemic regions were also obtained using a circumferential graph program (TOMO-MAX). In addition, regional myocardial 201Tl activity was recorded continuously with a cadmium telluride radiation probe sutured directly to the posterior myocardial wall. Defects in 201Tl distribution with subsequent partial or complete redistribution were present in 11 of 12 central pinhole images and tomographic studies. In the normal and ischemic anterior myocardial segments the percentage change in 201Tl activity in the central pinhole image from occlusion to the end of reflow correlated well with the percentage change in activity for both TOMO-ROI (r = 0.93) and TOMO-MAX (r = 0.85). In the normal posterior segments the percentage change in 201Tl activity in the central pinhole image correlated well with TOMO-ROI (r = 0.98) and TOMO-MAX (r = 0.87).(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of myocardial preservation with hypothermic potassium and nifedipine arrest.

Preservation of regional myocardial function, high-energy phosphate stores and ultrastructure were assessed in 28 canine hearts subjected to 2 hours of global ischemia at either 12 degrees C or 21 degrees C. The preservation achieved with a potassium arrest solution was simultaneously compared in the same heart with either a nifedipine arrest solution or a potassium plus nifedipine arrest solution. There were no statistically significant differences in regional function recovery between the three arrest solutions at either temperature. At 12 degrees C, slightly better functional preservation was noted for each solution. End-systolic chord length was significantly less elongated after preservation at the lower temperature (p = 0.03). The concentration of ATP and myocardial water content were not significantly better preserved with any solution at either temperature. Myocardial ultrastructure was well preserved regardless of the solution or temperature used. The degree of hypothermia appears to be more important to functional preservation than differences between the three solutions tested. We conclude that with respect to preservation of myocardial function, high-energy phosphate stores, water content and ultrastructure, nifedipine arrest offers no advantages over potassium arrest.

Hypothermic ischemic arrest versus hypothermic potassium cardioplegia in human beings.

To determine if the addition of potassium enhances the myocardial protective effect of intracoronary perfusion hypothermia during aortic cross-clamping, 50 patients undergoing aortocoronary bypass grafting were studied in a randomized, prospective, double-blind fashion. Twenty-six patients received a cold crystalloid solution infused with a handheld syringe into the root of the cross-clamped aorta every 20 minutes, and 24 patients received the same solution but with 25 mEq/L of potassium chloride added, infused in a similar manner. Both groups were analyzed by mortality, rate of perioperative myocardial infarction (electrocardiographic changes, MB-CPK enzyme release, and preoperative and postoperative gated cardiac blood pool scans), intraoperative hemodynamic changes, intraoperative lactate determinations, postoperative arrhythmias, and requirement for pressor or intraaortic balloon pump support. One patient in the potassium cardioplegia group died (massive pulmonary embolism), and none in the hypothermic perfusion group died. Possible perioperative myocardial infarction was diagnosed by more than one marker in 4 of 26 patients in the hypothermic perfusion group and 5 of 24 patients in the potassium group (p = 0.61). There were no differences between the two groups in terms of hemodynamic changes, lactate production, postoperative arrhythmias, or the need for postoperative hemodynamic support. This study in human beings could not demonstrate a specific protective effect of potassium, beyond that afforded by myocardial perfusion hypothermia and wash-out. The data suggest that myocardial hypothermia, achieved through cold intracoronary arterial perfusion, may be the most important beneficial component of so-called cardioplegia for attaining effective intraoperative myocardial preservation in human beings.