Technological devices in peripheral percutaneous interventions.

New innovations and novel approaches to peripheral arterial occlusive disease have brought enormous benefits to the vascular patient. Diseases that were once manageable only by surgical intervention are now easily and successfully treated by minimally invasive procedures. While the early days of percutaneous intervention were filled with inventions of new devices, today the focus centers on using modern technology and manufacturing to further improve upon these devices. Advances in guidewires and catheters have allowed us to visualize and treat lesions in nearly any vessel, and technology is guiding us towards specialized applications for specific lesions in specific vessels. However, one of the big hurdles remaining in treating arterial occlusive diseases is the rate of restenosis and the need for reinterventions. The location and architecture of these vessels make them uniquely difficult to treat, and call for new technology to address these challenges. Current developments of drug-eluting and bioabsorbable stents are at the forefront of new advancements specifically directed at improving current patency and restenosis rates; perhaps the next step in percutaneous intervention will rely on nanotechnology and the molecular surface engineering that may achieve a new era of devices that are able to target specific cell ligands or proteins to prevent the inflammatory and proliferative response from vessels. The present review will focus on the current literature regarding technological devices in peripheral percutaneous interventions and clinical applications. Future advancements in materials engineering and biotechnology will continue to improve the current standard of percutaneous intervention for peripheral arterial occlusive diseases.

Computational study of haemodynamic effects of entry- and exit-tear coverage in a DeBakey type III aortic dissection: technical report.

OBJECTIVES: Outcome prediction in DeBakey Type III aortic dissections (ADs) remains challenging. Large variations in AD morphology, physiology and treatment exist. Here, we investigate if computational fluid dynamics (CFD) can provide an initial understanding of pressure changes in an AD computational model when covering entry and exit tears and removing the intra-arterial septum (IS). DESIGN: A computational mesh was constructed from magnetic resonance images from one patient (one entrance and one exit tear) and CFD simulations performed (scenario #1). Additional meshes were derived by virtually (1) covering the exit tear (false lumen (FL) thrombus progression) (scenario #2), (2) covering the entrance tear (thoracic endovascular treatment, TEVAR) (scenario #3) and (3) completely removing the IS (fenestration) (scenario #4). Changes in flow patterns and pressures were quantified relative to the initial mesh. RESULTS: Systolic pressures increased for #2 (300 Pa increase) with largest inter-luminal differences distally (2500 Pa). In #3, false lumen pressure decreased essentially to zero. In #4, systolic pressure in combined lumen reduced from 2400 to 800 Pa. CONCLUSIONS: CFD results from computational models of a DeBakey type III AD representing separate coverage of entrance and exit tears correlated with clinical experience. The reported results present a preliminary look at a complex clinical problem.

Carotid artery stenting--current status and future directions.

Carotid endarterectomy has been the standard of therapy for carotid occlusive disease in stroke prevention. More recently, carotid angioplasty and stenting became an important alternative in the treatment of carotid occlusive disease. The widespread use of cerebral protection devices has substantially decreased the morbidity of the procedure. As the experience with carotid stenting increases, so does the enthusiasm for the potential of this minimally invasive carotid intervention to become the main treatment option for the high risk patients, as well as for the average asymptomatic patient. Although current available data indicate that the results regarding success and complication rates are similar between carotid stenting and endarterectomy, several prospective clinical trials are currently in progress to evaluate the efficacy of carotid artery stenting in different patient populations and definitively establish its role in the treatment of carotid disease. This paper reviews the current status of carotid stenting, including results from clinical trials, technical aspects and controversial issues and strategies to provide cerebral protection from embolization.

Transcranial stab wounds: a report of three cases and suggestions for management.

Transcranial stab wounds are uncommon. Three such cases are presented. The severity of the wounds may vary from innocuous to devastating. Skull films are useful in delineating the depth of penetration. The presence of the knife blade in situ may make the computed tomographic scan impossible to perform or difficult to interpret. Cerebral angiography may be indicated if injury to a major cerebral vessel is suspected or if the patient suffers a delayed subarachnoid or intracerebral hemorrhage. Provided that the patient's clinical status indicates a positive prognosis, transcranial stab wounds should be explored surgically. The weapon should be removed in the operating room immediately before or at the time of operation.

Carcinoid tumour of the ampulla of Vater.

A 60 year old female with a carcinoid tumour of the ampulla of Vater is presented. The importance of considering this diagnosis in localized lesions of common bile duct or ampulla of Vater and thus avoiding more radical surgery is stressed.

Osteogenic sarcoma--a rare primary tumour of the breast.

A case of primary osteogenic sarcoma of the breast is reported and the histological and mammographic features demonstrated. A role for technetium 99 diphosphonate bone scanning in the diagnosis of this condition and measurement of serum alkaline phosphatase activity for monitoring progress of the disease is suggested.

The management of splenic artery aneurysms: experience with 23 cases.

BACKGROUND: Splenic artery aneurysms (SAA) are rare clinical entities that carry the risk of rupture and fatal hemorrhage. They are being detected with increased frequency and often cause a clinical dilemma, particularly when small lesions occur in compromised patients. This paper relates our experience in the management of SAA over a 14-year period. PATIENTS AND METHODS: We analyzed data from the medical charts and radiological images of all patients diagnosed with SAA at Emory University Hospital from December 1979 to January 1993. RESULTS: A search of medical records discovered 23 patients who experienced 44 SAAs during the time period under study. Twelve patients had multiple SAAs, most of them in the distal third of the artery. Seven had SAAs > 2 cm in diameter. Modalities used to diagnose SAA included Doppler ultrasound in 9 patients, computerized tomography in 10, and arteriography in 21. Sixteen patients had portal hypertension. Splenomegaly was present in 13 of those with portal hypertension. Aneurysm excision and splenectomy were carried out emergently on 2 patients and electively on 1. Aneurysm ligation was performed on 3 patients. One patient underwent embolization of the lesion. Sixteen asymptomatic patients whose aneurysms were < 2 cm in diameter were treated expectantly for a mean period of 3 years. One patient who received active treatment died. There were no documented deaths attributable to SAA among patients treated by observation. Six patients in this group died of unrelated causes. The longest follow-up was 7 years. CONCLUSIONS: We support current criteria that call for active treatment of symptomatic or enlarging SAAs, with particular emphasis on treating women anticipating pregnancy and patients undergoing orthotopic liver transplantations. For most other cases, expectant treatment is acceptable.

Endotoxemia during percutaneous manipulation of the obstructed biliary tree.

Fourteen patients undergoing percutaneous biliary manipulation were studied on 21 occasions. Using a chromogenic limulus-based assay technique, peripheral endotoxin concentration prior to the procedure was found to be 6.1 +/- 9 pg/ml, increasing to 30.7 +/- 26 pg/ml after the procedure (p less than 0.001). Fourteen of 21 bile cultures and only 1 of 21 blood cultures drawn during the procedure were positive for bacterial growth. There was a clinically modest but statistically significant decrease in blood pressure (p less than 0.05), an increase in temperature (p less than 0.01), and an increase in creatinine concentration (p less than 0.05) before and after biliary manipulation. The presence of infected bile and the preprocedure bilirubin level predicted development of endotoxemia.

Extrathoracic bypass procedures for proximal common carotid artery lesions.

During a 10-year period ending in December 1991, 31 extrathoracic bypass procedures were performed in 29 patients for proximal common carotid artery atherosclerotic stenosis or occlusion. This included 16 men and 13 women, with a mean age of 63 years. Indications for surgery included transient ischemic attacks in 23 patients (79%), nonfocal symptoms in 4 patients (14%), and asymptomatic proximal common carotid artery stenosis associated with near-total occlusion of the internal carotid artery in 2 patients (7%). Severe proximal stenosis or complete occlusion of the common carotid artery was demonstrated angiographically in all cases. Subclavian-to-carotid bypass was performed in 26 cases and carotid-to-carotid bypass in 5 cases. Seventy-four percent of the bypass procedures were to the common carotid artery and 26% to the external carotid artery. Endarterectomy of the common carotid bifurcation was performed in conjunction with the bypass procedure in 13 cases and vertebral artery transposition in 2 other cases. Saphenous vein was used as the bypass conduit in 65% and prosthetic grafts in 35% of cases. There were no perioperative strokes or deaths in this series, and the mean postoperative hospital stay was 5 days. Follow-up ranged from 2 to 118 months (mean: 38.4 months). Graft occlusion occurred in two cases during the follow-up period (3-year patency rate: 90%), with recurrence of symptoms in one patient, which necessitated revision. Three patients had persistence or recurrence of symptoms despite patency of the graft, one other patient sustained a posterior circulation infarct, and there was one death unrelated to carotid vascular disease during the follow-up period. This experience shows that extrathoracic bypass procedures are safe and well tolerated for symptomatic proximal common carotid artery stenosis or occlusion. This method of reconstruction has excellent long-term patency and protection against further anterior circulation neurologic events.

Hemodialysis access in the pediatric patient population.

BACKGROUND: Each year, three to five children per million develop chronic renal failure. Of these, 70% will require dialysis for short periods, and 23% will require prolonged hemodialysis support. It is in the latter group that difficulty is encountered in establishing dialysis access. METHODS: From 1985 to 1992, we provided hemodialysis access for a group of 24 children. There were 16 boys and 8 girls, with a mean age of 11.1 +/- 4 years (range 3 to 17). All children were significantly below the 50th percentile weight for their age and sex. Seven children entered hemodialysis following failed peritoneal dialysis after an average of 21 +/- 10.5 months. Seventeen patients received a renal transplant. Seven of these children have resumed hemodialysis. RESULTS: The technique for establishing hemodialysis was varied: 15 arteriovenous fistulae, 37 expanded polytetrafluoroethylene (ePTFE) bridge grafts, 9 bovine arteriovenous bridge grafts, and 29 chronic central venous catheters. The overall mean functional patency of the fistulae was 6.2 +/- 10.2 months. One third of these fistulae failed to mature sufficiently to permit their use for dialysis purposes. Twenty-one upper extremity ePTFE grafts were implanted, with a mean functional patency of 11 +/- 11.1 months. Sixteen groin loop grafts were utilized, with a primary patency of only 4.1 +/- 5 months. Thrombectomy was performed in 25 cases (patch or interposition in 8 cases), with a secondary patency in these grafts of 10.5 +/- 17 months. An inability to achieve access in 2 children resulted in the creation of unusual types of access: an aorto-caval fistula and an axillo-femoral fistula and a combination of single-needle puncture of an immature fistula with one lumen of a PermCath. There were eight ePTFE graft infections, with graft loss occurring in seven cases. Superior vena caval occlusion occurred in two patients, inferior vena caval thrombosis in one patient, and axillo-subclavian venous occlusion in two patients. Development of central venous occlusions significantly increased the difficulty in establishing dialysis access. The total dialysis period provided by the 90 primary procedures performed in this study was 658 months. Each procedure, therefore, provided access for a mean duration of only 7.3 months. CONCLUSION: Providing dialysis access in the pediatric population is a time-consuming and frustrating challenge. We believe that all patients with renal dysfunction should have their conditions managed as potential long-term dialysis candidates. Therefore, our philosophy is to achieve maximal use from each access site. Although the primary patency of upper-arm ePTFE grafts was greater than that for the forearm fistulae in this study, failure of the upper-arm graft can result in loss of that limb for the purposes of future dialysis access. Consequently, we strongly advocate the "distal before proximal" and "autogenous before prosthetic" dogma in providing pediatric hemodialysis access.

Acute lower extremity ischemia after cardiac surgery.

A retrospective review during a 5-year period (1987 to 1992) was conducted of all patients manifesting leg ischemia after major cardiac surgery. There were 7,620 procedures performed, and 65 (0.85%) patients (mean age: 65 years) were identified with acute ischemia. Diagnosis was made by physical examination, during which a cool pulseless extremity without pedal Doppler signals was noted in 63 of 65 patients (97%). An intra-aortic balloon pump (IABP) was inserted in 56 patients (86%). Treatment regimens included medical management (17), IABP removal (4), IABP removal and thromboembolectomy (24), thromboembolectomy and endarterectomy with patch angioplasty (10), femoral-femoral bypass (17), other bypasses (6), fasciotomy (10), and amputation (16). Morbidity was 92% and mortality was 46%. Mortality was 11% in those patients developing ischemia without an IABP. Acute leg ischemia after cardiac surgery is predictive of high morbidity and mortality. This reflects the compromised cardiac status and multi-system disease. Treatment alternatives are based on the overall clinical status, degree of arterial insufficiency, and distribution of pre-existing peripheral vascular disease. However, ultimate limb salvage had no influence on overall patient survival in our study.

Nonoperative management of visceral aneurysms and pseudoaneurysms.

During the period from 1975 to 1991, 41 patients with 60 visceral artery aneurysms were treated at the Affiliated Hospitals of Emory University. The total included 13 patients in whom 16 aneurysms were treated primarily by transarterial embolization. There were seven hepatic artery aneurysms, three splenic artery aneurysms, three gastroduodenal artery aneurysms, two left gastric artery aneurysms, and one right gastroepiploic artery aneurysm. Average age of these patients was 50 years; there were eight males and five females. Seven patients presented with gastrointestinal bleeding, and two patients presented with abdominal pain. In four patients, the aneurysm was an incidental finding. Etiology of the true or false aneurysms consisted of pancreatitis in two patients, trauma in three patients, connective tissue disease in one, and was unknown in the remainder. Embolization was performed in seven cases with Gianturco coils and Gelfoam, with coils alone in four, with Gelfoam alone in four, and with detachable balloons in one instance. Complete occlusion was achieved initially in 13 cases. Recanalization occurred in two patients over a mean follow-up period of 8.6 months, requiring re-embolization in one patient, whereas the other patient was managed expectantly. In three cases, embolization was unsuccessful: two cases required surgical correction, and one case was managed expectantly. Only one complication was related to the embolization procedure, which was a common hepatic arterial dissection that proceeded to the formation of a false aneurysm. Embolization as the primary treatment modality for visceral artery aneurysms should be considered in patients with the following diagnoses: pseudoaneurysms associated with pancreatitis, intrahepatic aneurysms, most splenic artery aneurysms, and gastric, gastroduodenal, and gastroepiploic aneurysms. The procedure has a low risk and may obviate a difficult surgical procedure, but it does not preclude surgical intervention should the need arise.

Acute occlusion of the abdominal aorta.

BACKGROUND: Acute aortic occlusion most commonly results from aortic saddle embolus or thrombosis of an atherosclerotic abdominal aorta. The purpose of this study was to review the experience at a university hospital to better define the diagnosis and management of this uncommon process. METHODS: A retrospective chart review was performed from patients admitted to Emory University Hospital with acute occlusion of the abdominal aorta from 1985 through 1997. RESULTS: Thirty-three patients were identified. In group EMB (n = 16), occlusion was due to saddle embolus. In group IST (n = 17), occlusion was attributed to in situ thrombosis of a severely diseased aorta. Operative procedures performed included transfemoral embolectomy (15), aorto-bifemoral bypass (9), axillobifemoral bypass (5), fasciotomy (3), and thrombolysis (1). The in-hospital mortality rate was 21% (31% EMB, 12% IST), and morbidity was significant and included mesenteric ischemia (6%), bleeding complications (9%), subsequent amputation (12%), renal failure (15%), recurrent embolization or thrombosis (21%), and cardiac complications (42%). CONCLUSIONS: Acute aortic occlusion has tremendous morbidity and mortality even with optimal surgical care.

Delayed rupture of aortic aneurysms following endovascular stent grafting.

BACKGROUND: Deployment of transfemoral, endovascular stent grafts for treatment of abdominal aortic aneurysms is appealing for several reasons: avoidance of abdominal incision, lack of aortic cross-clamping, potential for regional anesthesia, and shortened hospital stay. Concerns remain, however, regarding the ability of these devices to completely exclude the aneurysm and prevent aneurysm rupture and the long-term integrity of the device. The availability of endografts and the likely development of percutaneous devices have also raised the delicate issue of personnel training for patient selection, endograft implantation, and postoperative follow-up. PATIENTS AND METHODS: The cases of 2 patients are reported in which Dacron endovascular grafts, anchored proximally and distally by Palmaz stents, were deployed for treatment of infrarenal abdominal aortic aneurysms. RESULTS: In a patient with and absent distal cuff, choosing this procedure represented a clear error in patient selection. The endograft failed to reach the aortic bifurcation and the aneurysm ruptured, with the death of the patient 4 months postimplantation. In a patient with anatomy suitable for endograft placement, a perigraft leak persisted at the distal anastomosis following device placement. The aneurysm ruptured 14 days postprocedure. Although the patient survived emergent aneurysm repair, he developed acute renal failure. CONCLUSION: Careful preoperative assessment of aortic anatomy is crucial in selection of patients for transfemoral endovascular graft placement. Lack of a distal cuff of at least 1 cm precludes tube graft implantation. Patients with a perigraft leak are not protected by the endograft from aneurysm rupture. Vascular surgeons must be involved in the preoperative evaluation of these patients and are the only specialty group who can provide the prerequisite care in evaluation and management of postoperative complications.

The surgical anatomy and technique of the thoracoabdominal incision.

The thoracoabdominal incision provides excellent exposure of the thoracic, abdominal, and retroperitoneal compartments and can be safely performed in the vast majority of cases. To be more specific, the advantage of the left thoracoabdominal incision is excellent exposure of the lower esophagus, the gastroesophageal junction, the gastric cardia and stomach in toto, the left hemidiaphragm, the distal pancreas and spleen, the left kidney and adrenal gland, and the aorta. The advantage of the right thoracoabdominal incision is excellent exposure of the upper esophagus, the liver, the hepatic triad and inferior vena cava, the proximal pancreas, the right hemidiaphragm, the right kidney, and the adrenal gland. Several possible disadvantages should also be taken into consideration when contemplating this procedure. Morbidity and mortality may be increased with the opening of the two cavities. The surgeon must possess good detailed anatomic technique for opening and closure. This procedure is not advisable for children; it should be used only for good technical indications. Some of the more commonly encountered anatomic complications to be avoided include (1) splenic injury, occurring most often during division and resection of the diaphragm; (2) phrenic nerve injury, with subsequent diaphragmatic dysfunction; (3) ureteric injury during retroperitoneal dissection; (4) left first lumbar vein injury (located in the posterior aspect of the left renal vein) during left kidney mobilization; and (5) pain in the early postoperative period, which can occur secondary to transection of the cartilaginous costal arch. This may be minimized by secure fixation using No. 1 Prolene. Patients occasionally complain of a clicking sensation owing to nonunion of the costal cartilage.

Infrainguinal bypass in end-stage renal disease: when is it justified?

Management of the patient with end stage renal disease and peripheral vascular disease represents a major challenge to the vascular surgeon. In this review, we developed guidelines for intervention based on our own institutional experience as well as literature review. There have been more than 290 patients reported to have 369 ischemic legs with threatened limb loss. There was an overall graft patency rate of 71% (range, 64% to 77%) and 60% (range, 48% to 90%) for 1 and 2 years, respectively. The mean limb salvage rate was 72% (range, 52% to 94%) at 2 years in these groups of patients. In the presence of rest pain and/or tissue loss, with favorable inflow and outflow (at least one vessel with direct flow into the foot), we strongly advised surgical bypass. In those patients who presented with rest pain and/or tissue loss, infragenicular surgical reconstruction led to a higher quality of life in comparison to patients with primary amputations. An indication for a primary amputation would be gangrene extending proximal to the mid foot. We have therefore outlined our findings and thoughts in the following article.

Prevention of compartment syndrome associated with dorsal lithotomy position.

There is a clear association between the dorsal lithotomy position and the development of a postoperative compartment syndrome. Compartment syndrome occurs when elevated pressure in an osteofascial compartment compromises local perfusion and often results in neurovascular damage and permanent disability. Surgeons must recognize this association and provide appropriate preventative measures, have a high index of suspicion in all patients, and be prepared to make an early diagnosis when it is encountered. We will report four cases we encountered, discuss the etiology, analyze the literature, and propose a modification on patient positioning that has minimized the incidence of compartment syndrome at our institution. A variety of intraoperative events, including hypotension, hypoxemia, leg elevation, hip and knee flexion, direct pressure, and compressive bandages may all contribute to compartmental ischemia. Ischemia is followed by reperfusion, capillary leakage from the ischemic tissue, and a further increase in tissue edema. Increased edema causes further embarrassment of perfusion and perpetuation of the cycle, ultimately resulting in neuromuscular compromise secondary to ischemia. To prevent this destructive cycle, emphasis must be placed on maintaining a high index of suspicion in all patients, minimizing leg elevation, and on the importance of early diagnosis and intervention.

Vascular complications in Ehlers-Danlos syndrome.

Ehlers-Danlos syndrome (EDS) type IV results in a high incidence of vascular lesions. The extreme fragility of arteries is associated with multiple aneurysm formation, spontaneous rupture, and dissection. Surgical management of patients with this disorder is hazardous and often unrewarding. In this report we describe the difficulties encountered in the management of three patients with EDS-related vascular lesions. Three patients presented with pain and exhibited characteristic features of EDS. Diagnostic modalities included computerized tomography, transesophageal echocardiography, and magnetic resonance. Aortography was performed only in specific situations. One patient with pericardial and mediastinal hemorrhage was stabilized and treated conservatively, with a good outcome. An adolescent with a ruptured aortic pseudoaneurysm died at surgery. The third patient underwent successful surgical correction of multiple aortic and renal aneurysms. In view of the increased risk of fatal vascular complications, surgeons should identify patients with EDS before performing invasive procedures. Arteriography should be used only when necessary. Although operative mortality remains at a high level due to the tendency of vessels to tear with even minimal manipulation, mortality from hemorrhage without surgical intervention is even greater. The key to favorable outcomes lies in identification of the syndrome preoperatively, surgical intervention only in life- or limb-threatening situations, and appropriate modification of surgical technique.

Carcinosarcoma of the gallbladder: a case report and review of the literature.

A case of pedunculated carcinosarcoma of the gallbladder, presenting with common duct obstruction is reported; radiological, operative and pathological findings are described. The patient was treated with cholecystectomy, common bile duct exploration and postoperative radiotherapy applied through a t-tube. Only 20 cases of carcinosarcoma of the gallbladder have been described. The current state of knowledge regarding the natural history of these tumors are reviewed.

The surgical anatomy of the deep femoral artery.

Lower extremity ischemia is a common disorder that in the majority of cases is associated with occlusion of the superficial femoral artery. The deep femoral artery is recognized as an important collateral pathway to the genicular arterial system, thus accounting for the appearance of symptoms only after its involvement in the disease process. Surgical exposure of the deep femoral artery is often necessary in vascular reconstructive procedures. Furthermore, because it supplies the bulk of the thigh musculature, plastic surgeons have shown great interest in the muscular branches of the deep femoral artery when designing procedures that incorporate myocutaneous flaps. This article gives a detailed account of the embryology, anatomical relations, important variations, and branches of the deep femoral artery. Recommendations for the surgical exposure of this artery at different levels are also presented.