Thoracic outlet syndrome: case report and review

Thoracic outlet syndrome is caused by a large number of etiologies, which can affect the elements of the neurovascular bundle in combination or separately. The radiology department offers many imaging modalities which can assist in determining which structures may be involved as well as suggest possible etiology. The interventional radiologist, often working in conjunction with the surgeon, can assist in the treatment of many arterial or venous disorders, such as stenosis or thrombosis commonly seen in patients with Thoracic outlet syndrome.

Endothelial cell regrowth and morphology after balloon catheter injury of alloxan-induced diabetic rabbits

Neointimal thickening after catheter injury has been reported to be influenced by the integrity of the vascular endothelium. We have previously shown that neointimal thickening is significantly reduced in alloxan-induced diabetic New Zealand White rabbits after catheter injury compared with euglycemic rabbits. In the present study, it was hypothesized that endothelial cell regrowth, morphology, and endothelium-dependent vasoreactivity after catheter injury are improved in the diabetic rabbit (glucose >/=400 mg/dl) compared with the euglycemic rabbit. Two weeks after catheter injury, the percent endothelial regrowth was significantly increased in diabetic animals compared with euglycemic animals (32.1 +/- 2 and 15.6 +/- 1, respectively; P < 0.05). The endothelial cell morphology analyzed by scanning electron microscopy was also restored 2 wk after catheter injury in thoracic aortas from the diabetic animals compared with vessels from euglycemic animals. Endothelium-dependent relaxation to ACh in vessels from diabetic and euglycemic rabbits was attenuated 2 wk after injury, and, although improved by 4 and 8 wk, relaxation remained significantly depressed. These results suggest that endothelial cell regrowth and morphology in diabetic animals was improved compared with euglycemic animals; however, endothelium-dependent vasoreactivity remained impaired. Thus the attenuated neointimal thickening seen in the diabetic rabbit may be a function of the rate and degree of regrowth rather than the normalization of ACh-induced relaxation.

Concurrence of anaphylaxis and acute heparin-induced thrombocytopenia in a patient with heparin-induced antibodies

We report the occurrence of acute heparin-induced thrombocytopenia in a patient with anaphylaxis that began immediately after an intravenous bolus dose of unfractionated heparin. This case report is the first to document the concurrence of these 2 reactions to heparin. An abrupt fall in platelet count was documented immediately after the anaphylactic response. Study results for antibodies characteristic of heparin-induced thrombocytopenia were positive in 2 assays: serotonin release assay and heparin platelet factor 4 enzyme-linked immunosorbent assay. The patient's antibody was exclusively immunoglobulin G. Any explanation for the relationship between the antibody response observed and the histamine release remains speculative.

A thermodynamic investigation of reactions catalyzed by tryptophan synthase

Microcalorimetry and high-performance liquid chromatography have been used to conduct a thermodynamic investigation of the following reactions catalyzed by the tryptophan synthase alpha 2 beta 2 complex (EC 4.2.1.20) and its subunits: indole(aq) + L-serine(aq) = L-tryptophan(aq) + H2O(1); L-serine(aq) = pyruvate(aq) + ammonia(aq); indole(aq) + D-glyceraldehyde 3-phosphate(aq) = 1-(indol-3-yl)glycerol 3-phosphate(aq); L-serine(aq) + 1-(indol-3-yl)glycerol 3-phosphate(aq) = L-tryptophan(aq) + D-glyceraldehyde 3-phosphate(aq) + H2O(1). The calorimetric measurements led to standard molar enthalpy changes for all four of these reactions. Direct measurements yielded an apparent equilibrium constant for the third reaction; equilibrium constants for the remaining three reactions were obtained by using thermochemical cycle calculations. The results of the calorimetric and equilibrium measurements were analyzed in terms of a chemical equilibrium model that accounted for the multiplicity of the ionic states of the reactants and products. Thermodynamic quantities for chemical reference reactions involving specific ionic forms have been obtained. These quantities permit the calculation of the position of equilibrium of the above four reactions as a function of temperature, pH, and ionic strength. Values of the apparent equilibrium constants and standard transformed Gibbs free energy changes delta r G'(m) degree under approximately physiological conditions are given. Le Châtelier's principle provides an explanation as to why, in the metabolic pathway leading to the synthesis of L-tryptophan, the third reaction proceeds in the direction of formation of indole and D-glyceraldehyde 3-phosphate even though the apparent equilibrium constant greatly favors the formation of 1-(indol-3-yl)glycerol 3-phosphate.

Analysis of responses to human synthetic adrenomedullin and calcitonin gene-related peptides in the hindlimb vascular bed of the cat

Vasodilator responses to human adrenomedullin (hADM), a newly discovered hypotensive peptide, human calcitonin gene-related peptide-alpha (hCGRP-alpha) and hCGRP-beta, which share structural homology with hADM, were compared in the hindlimb vascular bed of the cat under constant flow conditions. Injections of hADM (0.003-1 nmol), hCGRP-alpha, and hCGRP-beta (0.003-0.3 nmol) into the perfusion circuit caused dose-related decreases in hindlimb perfusion pressure. Vasodilator responses to hCGRP-alpha and hCGRP-beta were similar in potency and duration, and the doses of hCGRP-alpha and hCGRP-beta required to reduce hindlimb perfusion pressure 40 mm Hg (ED40 mm Hg) were significantly lower than the ED40 mm Hg for hADM. The duration of the hindlimb vasodilator responses to hCGRP-alpha and hCGRP-beta were significantly longer than the duration of the response to hADM. Amylin, a peptide that shares structural homology with ADM and with CGRP, had no significant effect on hindlimb perfusion pressure when injected in doses up to 1 nmol. Decreases in hindlimb perfusion pressure in response to hADM, hCGRP-alpha, and hCGRP-beta were not altered by L-N5-(1-iminoethyl)-ornithine (L-NIO) in a dose of the nitric oxide synthase inhibitor that decreased the vasodilator response to acetylcholine or by the cyclooxygenase inhibitor, meclofenamate, in a dose that decreased the vasodilator response to archidonic acid. The present data demonstrate that hADM, hCGRP-alpha, and hCGRP-beta have potent, but relatively short-lasting, vasodilator activity, and that vasodilator responses are not dependent on the release of nitric oxide or vasodilator prostaglandins in the hindlimb vascular bed of the cat.

Effect of short-term treatment with a monoclonal antibody to P-selectin on balloon catheter-induced: intimal hyperplasia, re-endothelialization, and attenuation of endothelial-dependent relaxation

The effects of an anti-P-selectin monoclonal antibody (MAb, PB1.3; Cytel Corporation) on neoendothelialization; neoendothelial function, as evidenced by acetylcholine-induced relaxation (nitric oxide formation); and intimal hyperplasia following embolectomy catheter-induced injury to the rabbit thoracic aorta were investigated. Catheter injury was induced in two groups of New Zealand White rabbits. One group received no treatment, while the second group received short-term treatment with the MAb (i.p., immediately before and 12 h after induction of catheter injury). A third group underwent a sham operation and served as uninjured controls. Following sacrifice at 2 weeks after injury, aortic rings were assessed for degree of intimal hyperplasia, neoendothelial morphology (scanning electron microscopy), and acetylcholine-induced relaxation. Aortic tissue from catheter-injured animals that received treatment exhibited improved neoendothelial morphology, as compared with tissue from untreated but catheterized animals; however, no statistically significant attenuation of the hyperplastic response or improvement in the attenuated neoendothelial-dependent acetylcholine-induced relaxant response that is characteristic of neoendothelium that forms after catheter denudation was observed. These data suggest that short-term attenuation of P-selectin-mediated polymorphonuclear leukocyte (PMN)/endothelium, PMN/platelet interactions, and/or thrombin formation beneficially affects neoendothelialization of the vascular wall following balloon catheter-induced injury.

Takayasu's arteritis: management of a complex case and literature review

Takayasu's arteritis, also known as pulseless disease, is an unusual cause of symptomatic peripheral vascular disease. It was first reported in 1908 by a Japanese ophthalmologist who described retinal arteriovenous shunts which appeared in a wreath-like distribution around the optic disc and microaneurysms of the retinal vessels in a 19-year-old Japanese woman. Onishi found similar findings in association with cool, pulseless upper extremities. Since that time the syndrome has been described as Takayasu's arteritis. The current report is of a 36-year-old black woman who presented with the complaints of blurred vision, dysphagia, headaches, and near syncopal episodes who had been diagnosed with Takayasu's arteritis 12 years previously. The presentation and operative management is described and this report also reviews the literature on the management of this syndrome.

Iliac vein compression syndrome: case report and review of the literature

Iliac vein compression syndrome is a clinical condition that occurs as a result of compression of the left iliac vein between the right iliac artery and the fifth lumbar vertebrae. Patients usually have marked edema of the left leg. We report a case of a 16-year-old man who sought medical attention with significant left lower leg edema and four previous episodes of left leg cellulitis. Evaluation demonstrated venous hypertension as a result of left iliac vein compression. The patient underwent surgical correction; his symptoms resolved. Details and management of the case are presented and discussed. A review of the current literature regarding this condition also is included.

The effect of carbon coating and porosity on early patency of expanded polytetrafluoroethylene grafts: an experimental study

PURPOSE

Synthetic vascular grafts have never achieved long-term patency comparable to autologous saphenous vein. Changes in graft wall porosity and carbon coating of the luminal surface have both been suggested to improve patency.

METHODS

Forty-two mongrel dogs, weighing 20 to 30 kg, underwent bilateral aortoiliac grafting with one of three randomly selected grafts: group I, 60 microns carbon-coated, thin-walled expanded polytetrafluoroethylene (ePTFE); group II, 60 microns thin-walled uncoated ePTFE; or group III, regular ePTFE. All grafts were 10 cm long and had an internal diameter of 5 mm. Twenty-one dogs were killed at 60 days and 21 dogs were killed at 120 days. Thus in each group there were 14 60 microns, thin-walled, carbon-coated ePTFE grafts; 14 60 microns, thin-walled, uncoated ePTFE grafts; and 14 regular ePTFE grafts.

RESULTS

At 60 days, 12 (85.7%) of 14 group I, 13 (92.3%) of 14 group II, and 9 (64%) of 14 group III grafts were patent. At 120 days, 12 (85.7%) of 14 group I, 11 (78.6%) of 14 group II, and 6 (42.9%) of 14 group III grafts were patent. The patency of the 60 microns carbon-coated, thin-walled ePTFE at 120 days was significantly improved compared with that of the regular ePTFE (p < or = 0.05). The patency of the 60 microns thin-walled uncoated ePTFE was improved relative to conventional ePTFE at 120 days, although this difference was not statistically significant. There was no significant difference in patency between 60 microns carbon-coated, thin-walled ePTFE and 60 microns thin-walled uncoated ePTFE. When the results were analyzed simply on the basis of graft porosity, the 60 microns porosity grafts had a significantly improved patency compared to the regular ePTFE at 120 days (p < 0.05). Histologically, the 60 microns porosity grafts had significantly better tissue ingrowth along their entire length, regardless of the presence or absence of carbon coating. This ingrowth was present at both 60 days and 120 days.

CONCLUSIONS

Our data suggest that increasing ePTFE graft porosity to 60 microns improves overall patency. However, the addition of carbon lining did not appear to further augment patency.

L-arginine inhibits balloon catheter-induced intimal hyperplasia

Intimal hyperplasia that results from therapeutic revascularization is an important etiologic factor in the failure of these procedures (i.e., restenosis). Drugs which donate nitric oxide have been shown to inhibit the proliferation of vascular smooth muscle cells in vitro. We tested the hypothesis that administration of L-arginine (0.5 g/kg/day), the precursor of nitric oxide, would inhibit development of intimal hyperplasia following balloon catheter-induced injury. L-arginine administration from 2 days prior to and 2 weeks following catheter-induced injury to the rabbit thoracic aorta attenuated the development of intimal hyperplasia by 39% as compared with untreated controls. This effect was due to decreased intimal area. The effect of L-arginine was inhibited by co-administration of an inhibitor of nitric oxide synthase, NG-nitro-L-arginine methyl ester (0.5 g/kg/day). These data demonstrate that L-arginine attenuates intimal hyperplasia and suggest that the mechanism for this effect is the conversion of L-arginine to nitric oxide.

Surgical repair of a celiac axis aneurysm and renal oncocytoma: a single case report

Visceral artery aneurysms are unusual lesions. However the frequency of diagnosis has increased in recent years as a result of increased utilization of arteriogram and computed tomographic (CT) scan. When diagnosed in conjunction with other syndromes, alternative treatment options can be utilized. The present case discusses a 67-year-old black male who presented with a right renal mass and celiac artery aneurysm. The renal mass was diagnosed as an oncocytoma. This unique anatomy enabled us to perform a right nephrectomy in conjunction with a celiac artery aneurysmectomy with primary anastomosis between the right renal artery and common hepatic artery. This case demonstrates our approach to an unusual problem.

Mycotic aneurysm of the tibioperoneal trunk: case report and review of the literature

Peripheral mycotic aneurysms can occur when septic emboli lodge in either the lumen or the vasa vasorum of a peripheral vessel. Such aneurysms have become rare after the widespread use of aggressive antibiotic treatment for bacterial endocarditis. We report the case of a large mycotic aneurysm of the tibioperoneal trunk 18 months after an episode of Streptococcus viridans bacterial endocarditis. Treatment included complete resection of the aneurysmal sac with restoration of circulation to the posterior tibial artery with a reversed saphenous vein graft. To our knowledge, this is the first case of a mycotic aneurysm of the tibioperoneal trunk reported in the English literature. It also represents the first case in which a mycotic aneurysm of an infrapopliteal vessel was managed successfully with restoration of circulation.

Neurovascular lower extremity complications of the lithotomy position

The lithotomy position is commonly used during the performance of a variety of abdominal and pelvic operations. Previous publications reporting complications with these operations have been largely anecdotal. We report our experience with eight patients over the past four years who have suffered serious lower extremity complications following operations in which the lithotomy position was used. The average time in the lithotomy position for our patients was 7.4 hours (range: 3.7-12 hours). The mean interval between the original operation and the secondary operation to treat the lower extremity complication was 18.9 hours (range: 2-51 hours). The average hospital length of stay for these patients, 38.4 days (range: 11-119 days), was often prolonged as a direct result of their limb complication. Serious lower extremity complications may result from operations in which the lithotomy position is used. To prevent such complications, strict attention should be paid to the positioning of the limbs in the operating room and the time in the lithotomy position should be minimized. Perioperative monitoring of the lower extremity circulation and compartment pressures are essential in these patients since early detection and treatment of these complications is the only way to prevent permanent limb injury.

Temporary closure of the abdominal wall by use of silicone rubber sheets after operative repair of ruptured abdominal aortic aneurysms

Management of patients after operative repair of abdominal aortic aneurysms can be further complicated if primary closure of the abdominal wall cannot be technically accomplished or is associated with profound increases in intraabdominal and peak inspiratory pressures. We recently treated five patients with ruptured abdominal aortic aneurysms and one patient with a ruptured thoracoabdominal aneurysm whose abdominal incisions had to be closed with a Dacron reinforced, silicone sheet. All patients were hemodynamically unstable either at admission to the hospital or became so during operation. Four patients required the insertion of a silicone rubber sheet at the primary operation because of massive retroperitoneal hematoma or edema of the bowel wall or both. Incisions in two patients were closed primarily, but the patients required reexploration and secondary closure with silicone rubber sheets because of the development of marked increases in peak inspiratory pressures, intraabdominal pressures, and decreased urinary output. Four of the six patients subsequently underwent successful removal of the silicone rubber sheets with delayed primary closure of the abdominal wall, and two others died before removal. The patient with the ruptured thoracoabdominal aneurysm died on postoperative day 20 because of pulmonary sepsis but had a healed abdominal incision. The three surviving patients have been discharged. A silicone rubber sheet may be necessary for closure of the abdominal wall after repair of ruptured abdominal aortic aneurysm in patients where primary abdominal wall closure is impossible or where it results in compromise in respiratory or renal function.

Complications of anomalous origin of the right subclavian artery: case report and review of the literature

A 35-year-old black woman presented with thrombosis of an anomalous right subclavian artery and distal arterial embolization. Initially, her right subclavian artery was reimplanted onto the common carotid artery, and a brachial artery embolectomy plus intraoperative thrombolytic therapy were used to reopen her distal arterial circulation. When her brachial artery repair thrombosed the following day, a distal ulnar artery bypass and repeat thrombolytic therapy were required to restore arterial patency. Six months later, she returned with severe, progressive, neointimal hyperplasia of her brachial artery and a second attempt at arterial reconstruction was unsuccessful. She eventually required a right below-elbow amputation. This patient demonstrated an anomalous right subclavian artery that presented with distal embolization without an antecedent history of severe atherosclerotic disease or the development of a right subclavian artery aneurysm. A review of the medical literature relating to complications of this anomaly is provided.

Femur fracture with limb shortening causing occlusion of a polytetrafluoroethylene femoral popliteal graft

Traumatic occlusion of lower extremity polytetrafluoroethylene arterial grafts is exceedingly rare. We report a patient who suffered a supracondylar femur fracture resulting in shortening of her right lower extremity with kinking and thrombosis of her above-knee polytetrafluoroethylene arterial graft. This is the first report in the English language of prosthetic graft occlusion as a result of traumatic limb shortening. The graft thrombus was successfully lysed by use of intraarterial urokinase, and the kink was repaired by graft resection and reanastomosis. The mechanism of injury and treatment are discussed.

Postoperative somnolence in patients after carotid endarterectomy

Eighty-one patients undergoing carotid endarterectomy were divided into two groups based on the degree of stenosis of the carotid artery. Group I, 37 patients, was defined as having severe carotid stenosis (greater than 70%). Group II, 44 patients, was defined as having mild (less than 40%) or moderate (40% to 70%) carotid artery stenosis. Both groups were evaluated for neurologic and psychologic changes in the postoperative period. Prospective analysis demonstrated no significant differences between groups I and II in the areas of cardiac disease, history of preoperative stroke, preoperative and postoperative hypertension, diabetes, or postoperative computed tomography changes. Group II had a significantly higher percentage of carotid artery ulceration (p less than 0.01). Postoperative analysis revealed 34 group I patients had 6 to 8 weeks of lethargy versus two group II patients (p less than 0.01). Eleven group I patients had headaches for the first week postoperatively versus three patients in group II (p less than 0.05). Four group I patients had paranoid ideation, and another four patients had clinical depression, but not one patient in group II (p less than 0.01) had these psychiatric disturbances. These data suggest that significant, reversible neurologic and psychologic changes can occur because of reperfusion after relief of severe stenosis of the carotid artery.

Abdominal aortic aneurysms

The diagnosis and management of abdominal aortic aneurysms has improved greatly since the first report of Matas. Improved awareness of the diagnosis and advances in diagnostic techniques have allowed the diagnosis to be made earlier in the course of disease. Improved operative skills and peri-operative management have significantly decreased the morbidity and mortality rates associated with surgical intervention.

Transtracheal needle catheter ventilation in complete airway obstruction: an animal model

Transtracheal needle catheter ventilation (TNCV) may be used as an alternative airway when contraindications to endotracheal intubation exist. A feline model tested the efficacy of low-flow oxygen delivery, and initial data were gathered to define proper catheter calibers to effect adequate oxygenation and ventilation. Cats were anesthetized, trachea intubated, and ventilated for 30 minutes with a pressure-regulated ventilator. Arterial and venous pressures were monitored, and a chest tube was inserted to measure intrathoracic pressures. Arterial blood gas analysis was performed every five minutes during the baseline period. The endotracheal tube was then removed, the trachea cross-clamped, and TNCV instituted. Oxygen flow rates of 1, 3, and 5 L/min were varied with catheter sizes of 14, 16, and 18 g. Data demonstrated that TNCV provided adequate oxygenation and ventilation with flow rates of 3 and 5 L/min with the 14- and 16-g catheters. Satisfactory oxygenation could be obtained with these flow rates with the 18-g catheter, but ventilation was inadequate. Ventilation was unsatisfactory with the 1 L/min flow rate in all catheter sizes. These preliminary data indicate that a minimum catheter:trachea cross-sectional area ratio of 0.03 may be required to obtain oxygenation and ventilation with low-flow oxygen rates of 3 to 5 L/min in cats.

Prostacyclin and thromboxane A2 formation by atherosclerotic carotid artery: comparison with normal aorta, saphenous vein, and platelets

Prostacyclin (PGI2) and thromboxane A2 (TxA2) formation by whole-tissue segments of nine carotid endarterectomy specimens (CES), five normal aortic specimens (NAS), six saphenous vein specimens (SVS), and four platelet samples were determined by incubation with 10 mumol/L 1-14C-radiolabeled prostaglandin endoperoxide H2 (PGH2), and in other experiments with and without 10 mumol/L of CGS 13080, a TxA2 synthase inhibitor. PGI2 formation (expressed as picomoles 6-keto-PGF1 alpha/2-min incubation per sample) by nonatheromatous proximal intima of CES (307 +/- 23, mean +/- standard error) and distal intima of CES (260 +/- 22) was not statistically different; however, it was greater than atheromatous transitional plaque (159 +/- 13 pmol) (p less than 0.01) and ulceration regions (140 +/- 15 pmol) (p less than 0.01) of CES, NAS (204 +/- 16 pmol) (p less than 0.01), and SVS (165 +/- 9 pmol) (p less than 0.01). TxA2 formation (expressed as picomoles TxB2/2-min incubation per sample) by CES ulceration (51 +/- 2 pmol) was low but greater than proximal (17 +/- 2 pmol) (p less than 0.01), distal (19 +/- 3 pmol) (p less than 0.01), and transitional (23 +/- 3 pmol) (p less than 0.01) regions. TxA2 formation by NAS and SVS was not detected (less than 10 pmol). CGS 13080 inhibited TxA2 formation by CES below the limits of detection. Incubation of 1.9 x 10(5) intact platelets with 10 mumol/L of PGH2 formed a quantity of TxA2 equal to that of CES ulceration.(ABSTRACT TRUNCATED AT 250 WORDS)

Does intracranial dye study contribute to evaluation of carotid artery disease?

One thousand consecutive cerebral arteriograms for suspected carotid artery disease were retrospectively evaluated for the intracranial disease component. Only 784 patients (78 percent) had arteriograms of the intracranial circulation. Forty-six patients (6 percent) had siphon stenosis in the range of 5 to 70 percent. No patient had a lesion encompassing more than 75 percent of the vessel diameter. Thirteen patients (2 percent) had intracranial aneurysms. All patients were asymptomatic from the standpoint of their aneurysms and none required surgical intervention. One additional patient was noted to have an intracranial tumor, which was confirmed by computerized tomography. In this patient population, intracranial dye study did not provide information that altered management.

Iliac vein bypass with autogenous saphenous vein for iliac vein compression syndrome

A case of chronic obstruction of the left iliac vein is presented. The patient had failed conservative management. Surgical reconstruction was performed using autogenous saphenous vein. The patient has done well; results of a venogram at six months postoperatively indicate the graft is still patent.

The value of aortic arch study in the evaluation of cerebrovascular insufficiency

In evaluation of extracranial carotid vascular disease, the use of arteriography has long been considered essential. With increasing expertise in noninvasive testing, the importance of extensive dye studies is being questioned. The data presented herein indicate that proper preangiographic evaluation of the patient population drastically reduces the possibility of missing significant intrathoracic pathologic processes. Two subsets of patients should be recommended routinely for dye studies: those patients with unequal upper-extremity blood pressures and those without pathologic neck findings on noninvasive testing to account for their symptoms. When these patients are recognized as having the potential for intrathoracic disease, dye studies can be performed in situations that will generate the highest yield. Even with the continued use of dye studies in evaluation of cerebrovascular insufficiency, elimination of the aortic arch study will drastically reduce the dye load and, thus, the associated morbidity.