Malignant fibrous histiocytoma arising from the superficial femoral artery.

Primary sarcomatous arterial tumors are rare. We have reported a case of malignant fibrous histiocytoma in an elderly woman successfully treated by resection of the involved femoral vessel and reconstruction with a PTFE graft. The long-term result in this patient is presently uncertain.

Linear response of collateral cerebral perfusion pressure during carotid clamping.

Phenylephrine is frequently used to increase systemic arterial pressure during carotid endarterectomy. However, little is known of its effect on collateral cerebral perfusion pressure, particularly in patients with high collateral cerebral vascular resistance who are at increased risk of cerebral ischemia during carotid clamping. We tested the hypothesis that this subset of patients can have collateral perfusion pressure, and hence collateral cerebral blood flow, increased in a predictable way by elevating systemic arterial pressure. We measured mean systemic arterial pressure (Pa), jugular venous pressure (Pv), and mean carotid back pressure (Pc), and calculated collateral cerebral perfusion pressure (P = Pc - Pv) and the ratio of collateral to ipsilateral hemisphere cerebral vascular resistance (Rc/Rh) in 18 patients with low P. Initial measurements were Pa = 84 +/- 8.8 (mm Hg, mean +/- SD), Pv = 7.8 +/- 3.9, Pc = 26 +/- 5.1, P = 18 +/- 4.5 and Rc/Rh = 3.4 +/- 1.15. During phenylephrine infusion, Pa = 108 +/- 11, Pc = 32 +/- 6.5, and P = 24 +/- 7.2, increases of 29, 23, and 33%, respectively (P less than 0.05). Unchanged were Pv = 8.2 +/- 4.1 (5%) and Rc/Rh = 3.5 +/- 1.30 (3%) (P greater than 0.8). The latter two findings indicate that cerebral perfusion pressure and mean systemic arterial pressure are linearly related according to the fluid mechanics equation governing these parameters: Pa = P(Rc/Rh + 1) + Pv. These results support the use of phenylephrine to increase collateral blood flow during carotid endarterectomy in patients with low cerebral perfusion pressure.

Accuracy of ultrasound arteriography in symptomatic patients with carotid bruits and negative or equivocal noninvasive testing.

Twenty patients with cervical bruits and complete noninvasive workup--including Doppler ultrasonography, oculoplethysmography, and carotid phonoangiography--were further studied with ultrasound arteriography and contrast angiography. This unique group of patients who had cervical bruit and equivocal noninvasive testing results were found to have 14 abnormal angiograms. The Doppler ultrasound arteriography demonstrated 100% sensitivity and 66.7% specificity by patient, when compared to contrast angiography.

A three year experience with needle catheter jejunostomy in a community hospital.

Sixty-one needle catheter jejunostomy procedures have been performed in a community hospital setting with no morbidity. The procedure has been used as an adjunct to a variety of surgical procedures. Upon review of patients receiving a needle catheter jejunostomy, we believe that there should be a wider application of this technique especially in the area of trauma and malignant disease.

Intraoperative assessment of carotid endarterectomy by electromagnetic blood flow measurements.

Intraoperative electromagnetic flow meter measurements were made after 143 carotid endarterectomies. Six (4.2 per cent) had low or no internal carotid artery blood flow, and four of these had a clear technical cause. After rearteriotomy, five had restoration of blood flow to the normal range. These data support the hypothesis that there is a small but significant instance of technical causes of immediate carotid endarterectomy failure which may not be detectable by observation and palpation. Postendarterectomy intraoperative internal carotid artery blood flow measurement is an acceptable method of detecting hemodynamically significant technical defects.

Collateral cerebral vascular resistance in patients with significant carotid stenosis.

This study tests, the hypothesis that asymptomatic patients with hemodynamically significant internal carotid artery stenosis have a lower ipsilateral collateral cerebral vascular resistance and hence greater blood flow than their symptomatic cohorts. We measured internal carotid artery blood flow and cerebral perfusion pressures intraoperatively prior to and after carotid endarterectomy in 35 symptomatic and 10 asymptomatic patients with hemodynamically significant internal carotid artery stenosis. When the stenosis produced 30% or greater reduction in blood flow the calculated nondimensional normalized ratio of collateral cerebral vascular resistance of ipsilateral hemisphere cerebral vascular resistance was 1.15 +/- 0.83 (mean +/- SD) for the 10 asymptomatic patients and 2.98 +/- 1.89 for the 35 symptomatic patients (p = 0.0044). For the subgroup of 22 patients with 50% or greater reduction in internal carotid artery blood flow the resistance ratios were 0.782 +/- 0.541 for the 5 asymptomatic patients and 3.21 +/- 2.26 for the 17 symptomatic patients (p = 0.029). These results suggest that asymptomatic patients with hemodynamically significant internal carotid artery stenoses have a lower collateral cerebral vascular resistance than their symptomatic cohorts. The low collateral resistance may provide an adequate collateral cerebral blood flow to prevent ischemia and symptoms.

Common femoral artery atherosclerotic occlusion. Difficult to diagnose but easy to treat.

Common femoral artery atherosclerotic occlusion in the absence of significant aorto-iliac stenosis is unusual. It commonly presents by history and physical examination and noninvasive testing as aorto-iliac disease, and thus the diagnosis is usually made by arteriography. In this article, we describe seven patients with this lesion who underwent revascularization because of ischemia. The six patients who had endarterectomy and patch angioplasty were treated successfully.

Pulmonary embolectomy for acute massive pulmonary embolism.

During the period from 1961 to 1981, 40 pulmonary embolectomies were performed in 39 patients who were in extremis at the time of initiation of cardiopulmonary bypass. In a 460-bed hospital with more than 17,000 acute admissions and 4,000 operations per year, this small number represents the few patients who are potentially salvageable by urgent embolectomy. Preoperative angiography was performed in 57% of the cases, and in another ten patients suspected of having pulmonary emboli, angiography prevented unnecessary thoracotomy. Despite their moribund condition, 43% of the embolectomy patients lived. Excluding two patients with tumor occlusion of the pulmonary arteries and three patients with chronic cor pulmonale from old pulmonary emboli, the survival rate was 50%. Ten patients died because of hypoxemia and hypotension prior to initiation of cardiopulmonary bypass, and seven died of myocardial depression of multiple etiologies. Portable cardiopulmonary bypass affords the possibility of survival in moribund patients with acute massive pulmonary embolism. Preoperative angiography is recommended to guide appropriate surgical management.

Determination of the hemodynamic significance of iliac artery stenosis by noninvasive Doppler ultrasonography.

The ability of common femoral artery Doppler blood flow velocity waveforms to predict the hemodynamic significance of aortoiliac artery stenosis was determined by comparing intraoperative pressure gradient and flow measurements with two noninvasive nondimensional Doppler velocity waveform indices. The Doppler velocity waveforms of 63 common femoral arteries were recorded preoperatively, and iliac artery pressure gradients and blood flows were measured intraoperatively in 48 nonoccluded arterial segments. The mean iliac artery pressure gradient at double resting flow was calculated for comparisons between patients. Two Nondimensional Doppler velocity waveform indices were calculated: the minimum to maximum velocity amplitude ratio and the maximum to mean velocity amplitude ratio. Both Doppler velocity ratios successfully distinguish arteries with minimal or no hemodynamically significant stenosis from arteries with hemodynamically significant stenosis (mean pressure gradient at double resting flow resting flow greater than 6 mm Hg). A minimum to maximum Doppler velocity ratio of less than 0.185 or a maximum to mean Doppler velocity ratio greater than 2.10 indicates hemodynamically significant aortoiliac stenosis. Superficial femoral artery occlusion was indistinguishable from mild iliac stenosis by the two Doppler velocity waveform ratios but was clearly distinct from significant iliac stenosis.

Hypogastric artery aneurysm: survival after rupture into the rectum.

We have described a 70-year-old man with rupture of a previously ligated hypogastric aneurysm. The first operation for multiple abdominal aneurysms was an aorto-bifemoral bypass with endoaneurysmorrhaphy of bilateral iliac aneurysms and proximal ligation of a right hypogastric artery aneurysm. Five months later, after the previously ligated hypogastric artery aneurysm ruptured into the rectum, endoaneurysmorrhaphy and suture ligation of all feeding orifices, creation of a Hartmann's pouch, and end-on colostomy were done. The patient is doing well at nine months' follow-up. We recommend aggressive surgical ablation of hypogastric artery aneurysms, with endoaneurysmorrhaphy and suture ligation of all "feeding" orifices.

Determinants of cerebral perfusion pressure during carotid endarterectomy.

To define cerebral perfusion pressure during carotid clamping, carotid back and jugular venous pressures were measured in 100 consecutive carotid endarterectomies in 92 patients. The mean +/- 1 SD was 40.5 +/- 16.0 mm Hg for carotid back pressure, 11.8 +/- 4.8 mm Hg for jugular venous pressure, and 28.7 15.4 mm Hg for cerebral perfusion pressure. A number of variables affect jugular venous pressure, including jugular vein compression, patient position, and the anesthetic type. The lower the carotid back pressure, the more likely that back pressure alone is poor determinant of cerebral perfusion pressure and, hence, of the adequacy of collateral cerebral blood flow. To accurately use the carotid back or stump pressure method. The jugular venous pressure must also be measured, and the cerebral perfusion pressure must be calculated. Based on established safe levels of cerebral blood flow, it is probable that patients who undergo a carotid endarterectomy with a cerebral perfusion pressure of less than 18 mm Hg have cerebral ischemia and may require a shunt. Selective shunting, based on the cerebral perfusion pressure, gave a 1% mortality and 2% permanent neurologic deficit in this series.

Intraoperative assessment of the hemodynamic significance of iliac and profunda femoris artery stenosis.

The hemodynamic significance of stenosis was defined by intraoperative measurement of pressure and flow across 22 profunda femoris and 44 iliac artery segments. Measurements were taken at rest and during papaverine-induced vasodilation, and the mean pressure gradient across the arterial segment at double resting flow was calculated. Profunda femoris artery mean pressure gradients at resting flow were less than or equal to 3 mm Hg for stenoses up to and including 75%. The mean pressure gradient at double resting flow increased significantly in profunda femoris arteries with greater than 60% stenosis and was greater than 10 mm Hg in 7 of 10- profunda femoris arteries with 60% to 70% stenosis. Resting mean iliac artery pressure gradients were less than 10 mm Hg in 38 of 39 arteries with less than 90% stenosis and less than 5 mm Hg in 35 of 39. The mean iliac artery pressure gradient at double resting blood flow exceeded 10 mm Hg in 11 of 12 arteries with greater than 70% stenosis and was greater than 8 mm Hg in all 12. Four of 19 iliac arteries in the range of 20% to 65% stenosis as measured by arteriography had pressure gradients at double resting flow greater than 10 mm Hg. These results indicate that the hemodynamic significance of profunda femoris artery stenosis can be determined by intraoperative measurement of mean pressure gradients at double resting blood flow. Mean iliac artery pressure gradients at double resting blood flow may be useful for estimating the hemodynamic significance of iliac stenosis in situations where angiographic findings show mild-to-moderate iliac stenosis.

Semi-elective portal systemic shunts for variceal bleeding.

Between June 1977 and November 1980, we performed portal systemic shunt operations on eight patients for esophageal bleeding secondary to portal venous hypertension. One patient had operation as an emergency and the other seven semi-electively during the same hospitalization as admission. The patient operated upon as an emergency was the only hospital death. Life table analysis on this small group of patients indicates that semi-elective portal systemic shunt surgery after hemodynamic stabilization, nutritional support, and improvement of hepatic function is a viable alternative to emergency operation that can be done effectively in a community hospital.

Leiomyosarcoma of the rectum: the military experience.

Leiomyosarcoma of the rectum is a rare neoplasm and may behave in a highly malignant manner. Our experience with a single case prompted a review of the Armed Forces Central Medical Registry (AFCMR), where six other cases were found from the total AFCMR population. Four patients were treated with abdominoperineal (AP) resection; three had local excision only. Three patients developed metastatic disease and two of those died. The authors recommend prompt wide excision (AP resection) for any case of leiomyosarcoma of the rectum.

Critical stenosis of the internal carotid artery.

To better define the hemodynamic significance of internal carotid artery stenosis, intraoperative electromagnetic blood flow measurements were taken in 47 patients before and after carotid endarterectomy. When the ratio of pre- to postendarterectomy blood flew (Qpre/Qpost = Y) is compared to the fractional percent of internal carotid artery stenosis (X), the linear regression lines for the 25 arteries with Qpre/Qpost less than 0.70 are Y = -2.67 x +2.59 and Y = -10.10 x +10.06, respectively, for diameter and area stenosis. The intercepts of the regression lines with (a) Qpre/Qpost = 1 (normal blood flow) are 60% diameter and 90% are stenosis, (b) Qpre/Qpost = 0.60 (40% reduction in blood flow) are 75% diameter and 94% are stenosis and (c) with Qpre/Qpost = 0.36 (64% reduction in blood flow) are 84% diameter and 96% area stenosis. These data indicate that a critical or hemodynamically significant internal carotid artery stenosis may be of a higher grade than previously appreciated and that a stenosis greater than 75% diameter or 94% area may be necessary to symptomatically reduce cerebral blood flow.

Spontaneous mediastinal emphysema.

Several cases of spontaneous mediastinal emphysema have been seen and treated at two Air Force Hospitals. All have responded to nonsurgical treatment, and have been returned to normal duty or school.