Popliteal artery thrombosis associated with trampoline injuries and anterior knee dislocations in children.

Recent reports have emphasized the benign nature of trampoline-associated injuries. However, this study describes the limb-threatening problem of popliteal artery thrombosis occurring in association with anterior knee dislocation and trampoline injuries. Three children (ages 11, 13, and 17) were referred to the emergency room within the past 12 months with anterior dislocations of the knee, which occurred while jumping on trampolines. All patients had reduction of their dislocations at outside facilities and were referred within 6 to 12 hours after their injuries, with pulse, motor, and sensory deficits. All patients were taken directly to the operating room, where arteriography confirmed thrombosis of the popliteal artery below the knee. One patient had transection of the artery, whereas two patients had stretch injuries with intimal separation. Each patient required interposition grafting with reversed saphenous vein and underwent concomitant four-compartment fasciotomy. All patients had persistent sensory and motor deficits postoperatively, which were presumed to be a combination of ischemic injury and neuropraxia. All patients have functioning grafts with an average follow-up of 1 year (range, 9-15 months). One patient required a second interposition graft to treat an area of intimal hyperplasia, which developed at the proximal anastomosis, at 6 months postoperatively. Eighty per cent of trampoline injuries are associated with minor injuries with minimal long-term complications. However, dislocations of the knee may be associated with significant arterial injury and amputation rates of up to 30 per cent in many blunt trauma series. Based on our experience, physicians should recognize the possibility of significant arterial injuries occurring in children with anterior knee dislocations while jumping on trampolines.

Nontraumatic lower-extremity acute arterial ischemia.

BACKGROUND: The outcome of arterial bypass reconstruction in the setting of acute arterial ischemia has not been well defined. METHODS: This retrospective review consists of 71 consecutive patients (54 with native arterial thrombosis, 17 with graft thrombosis) who underwent an urgent/emergent arterial bypass reconstruction for acute arterial ischemia with threatened limb viability. RESULTS: The 30-day mortality and major amputation rates were 9.9% and 7.1%, respectively. Death, limb loss, or both, were associated with a paralytic limb (P = 0.001) and congestive heart failure (P = 0.03). Overall, 45 of 71 (63%) patients were discharged with limb salvage and ambulatory function. Cumulative graft patency was 77% and 65% at 1 and 2 years, respectively, and closely approximated the 1- and 2-year limb-salvage rates of 76% and 63%, respectively. CONCLUSIONS: Arterial bypass reconstructions appear warranted in acute arterial ischemia, in that a majority of patients retain a functional viable limb. Late graft thrombotic complications limit long-term benefit.

Process improvements reduce utilization of resources for aortic aneurysm repair.

In conjunction with the VA reorganization to promote greater efficiency of health care provision, ambulatory surgery (AS) programs have been created. These programs institute outpatient preoperative assessment and operative management. This study examines the impact of these process changes on resources utilized by patients requiring repair of abdominal aortic aneurysms (AAAs). The medical records of 15 consecutively treated patients undergoing elective, infrarenal AAA repair before (1992-1993) and after (1995-1996) AS implementation were reviewed. Resource utilization was assessed by evaluating preoperative tests performed (inpatient or outpatient), ICU days, and inpatient length of stay (LOS). Postoperative morbidity and mortality were noted. Patient age, AAA size, and prevalence of diabetes mellitus, hypertension, cardiac disease, COPD, and tobacco use were similar between the two groups. Abdominal ultrasound, CT scanning, and angiography were significantly more frequently performed on an outpatient basis after implementation of the AS program. The median preoperative LOS was reduced in the AS group (1 vs 6 days, P = 0.001, Student t test), resulting in a lower inpatient LOS (11 vs 16, P < 0.01, Student t test). All patients survived and the incidence of complications was similar between the groups. Hospital resource utilization was significantly decreased, largely by shifting preoperative assessment to the outpatient setting. This study illustrates that benefits of an ambulatory surgery program can be extended beyond facilitating outpatient operations and should result in decreased length of hospitalization for other major surgical procedures, such as abdominal aortic aneurysm repair.

Carotid endarterectomy results from a state vascular society. Kentucky Vascular Surgery Society Study Group.

PURPOSE: This study analyzes the results of carotid endarterectomy (CEA) performed statewide by members of the Kentucky Vascular Surgery Society (KVSS). METHODS: Between September 1, 1991 and September 1, 1993, 22 vascular surgeons in the KVSS submitted 1490 CEAs to the vascular registry. Follow-up data were obtained on 986 (66%) CEAs performed on 889 patients (average age, 68 years). RESULTS: Carotid endarterectomy was performed on 505 men and 384 women. Indications for operation were asymptomatic carotid stenosis (43%), transient ischemic attack (TIA; 27%), amaurosis fugax (13%), stroke (11%) and nonhemispheric symptoms (6%). A total of 384 cases had primary closure, and 602 had patch reconstruction following CEA. The combined stroke-mortality rate was 2.3% (10 strokes and 13 deaths). The combined stroke-mortality rate of CEA was 2.1% for patients treated by academic surgeons and 2.3% for those treated by community surgeons. Deaths were due to stroke (4), sepsis (5), cardiac complications (2), intracerebral hemorrhage (1) and cancer (1). Five patients had postoperative TIAs. After CEA, duplex scan surveillance was performed in 629 (64%) patients, with 23 (3.6%) residual/recurrent stenosis (10, 50%-75%; 13, 75%-99%) detected; 5 undergoing reoperation. CONCLUSIONS: These data support the efficacy and safety of CEA performed by a large number of vascular surgeons in both community and academic practice.

Aortoscopy: a guidance system for endoluminal aortic surgery.

PURPOSE: The aim of this project was to evaluate the feasibility of aortoscopy for guidance of endoluminal aortic procedures and to determine whether aortoscopy has advantages over fluoroscopy in a pig model. METHODS: To establish feasibility aortoscopic guidance was used for making endoluminal aortic measurements, cannulating small arteries for arteriograpy, and placing intraaortic stents and grafts in 11 pigs. To compare aortoscopy and fluoroscopy measurements were made and stents were placed by a surgeon using only aortoscopic guidance in 10 pigs and by an interventional radiologist using only fluoroscopic guidance in 10 pigs. Postmortem dissections were performed to determine measurement and device placement accuracy. RESULTS: In the feasibility study aortoscopic measurements differed from postmortem measurements by a mean distance (+/- SD) of 1.2 +/- 0.2 mm. Stents and grafts were placed a mean of 2.3 +/- 1.9 mm distal to the most inferior renal artery with no stent covering an orifice. All attempts at cannulating spinal arteries greater than 2 mm in diameter were successful. In the comparison of aortoscopic and fluoroscopic guidance, fluoroscopic measurements differed from postmortem measurements by 2.6 +/- 2.4 mm (p = 0.223). Stents placed with aortoscopic guidance were 1.1 +/- 1.3 mm distal to the most inferior renal artery, whereas stents placed with fluoroscopic guidance were 3.4 +/- 2.5 mm distal to the most inferior renal artery (p = 0.019). CONCLUSIONS: These results demonstrate that aortoscopy is a useful guidance system for endoluminal aortic procedures and may have advantages over fluoroscopy alone.

Angioscopic evaluation of an endoluminal aortic graft: the first clinical experience.

PURPOSE: Balloon aortoscopy has been described for viewing aortic endoluminal anatomy and guiding aortic stent placement in animals. We report the first clinical use of this technique to visually inspect the proximal portion of a 1-year-old endovascular aortic graft, its proximal fixation stent, and its relationship to the renal arteries. METHODS: The aortoscope is a modified fiber-optic endoscope that is fitted over the lens with a transparent, saline-filled balloon for blood displacement. Its performance was evaluated in a 62-year-old woman who had a Parodi-type Dacron/modified Palmaz stent endoluminal graft implanted to exclude an infrarenal aortic aneurysm in 1994. One year later, during an angioplasty procedure for symptomatic left subclavian and left common iliac artery stenoses, the 1-year-old endoluminal graft was inspected with the balloon-tipped angioscopic assembly. RESULTS: Introduced via the left brachial artery, the aortoscope provided a panoramic view of the endoluminal surface through the solution-filled balloon. The endoluminal aortic graft was clearly identified, as were both renal artery orifices proximal to the graft. The surface of the proximal stent was smooth and without exposed metal. No complications occurred with the angioscopy technique. CONCLUSIONS: Aortic angioscopy can be used to evaluate endoluminal aortic grafts and endoluminal anatomy. It provides clear, magnified views that may be useful for guiding precise placement and assessing the function and healing of endoluminal devices in the aorta.

Alcohol and drug use by surgery residents.

BACKGROUND: Although the use of alcohol and drugs by surgery residents is of concern, no large-scale studies of this specific population exist. STUDY DESIGN: A one-page, 36-item questionnaire on frequency of use of alcohol and drugs was administered to residents at the conclusion of the American Board of Surgery In-Service Examination. RESULTS: The survey showed that the use of drugs by surgery residents is relatively low when compared to drug use by other physicians. However, alcohol abuse continues to be a problem, and alcohol is the drug of choice of most residents. Cocaine used by surgery residents is generally obtained from hospital sources. CONCLUSIONS: Despite the optimistic findings of the survey, the authors advocate the following: Implementation of educational programs to prevent potential abuse of alcohol and drugs, and establishment of tighter controls on cocaine or use of a cocaine substitute for patient care.

An angioscopic method for intraluminal aortic evaluation and stent placement.

PURPOSE: The purpose of this study was to develop an angioscopic technique to visualize the endoluminal surface of the aorta and to guide vascular stent placement. METHODS: A fiberoptic angioscope, fitted with a balloon at its tip, was passed via a carotid arteriotomy into the abdominal aorta of seven anesthetized pigs. Saline solution inflation of the balloon allowed for blood displacement and clear visualization of the endoluminal anatomy. After the left renal artery orifice had been identified with angioscopy, a catheter was inserted via a left femoral sheath to cannulate the orifice under direct visualization. The position of the catheter was verified angiographically. A vascular stent was loaded onto an angioplasty balloon, inserted through a right femoral arteriotomy, positioned by use of angioscopic visualization, and deployed immediately below the left renal artery orifice. RESULTS: The aortic trifurcation and the lumbar and renal artery orifices were clearly visualized in every animal. Vascular stents were placed in seven animals within an average of 3.14 +/- 1.14 mm (mean +/- SEM, range 0 to 8 mm) below the inferior rim of the left renal artery orifice. No stents were positioned above a renal artery orifice or obstructed blood flow. CONCLUSIONS: This angioscopic technique permitted detailed evaluation of aortic endoluminal anatomy and precise implantation of vascular stents. Direct endovascular visualization may facilitate other endovascular procedures, including endovascular grafting.

Morphology predicts rapid growth of small abdominal aortic aneurysms.

This study evaluated CT scans of small abdominal aortic aneurysms (AAAs) (< 5 cm) to assess anatomic features associated with rapid expansion. Serial CT scans obtained at least 10 months apart (mean 15 months) from patients with small AAAs were reviewed. Each cross-sectional image of the AAAs was analyzed using a computer-assisted design program. The circumference of the AAA in each CT image was divided into eight equal arcs, from which the apparent radius of curvature (Rc) for each segment was calculated. Flattening of the wall curvature results in an increased segmental Rc. The CT scans of nine patients with expanding AAAs (expansion > or = 0.5 cm/yr) were compared to those of 10 patients with stable AAAs (expansion < or = 0.2 cm/yr). To adjust for differences in AAA size, the Rc for each segment was normalized by dividing each individual Rc by the average of the eight Rcs (RcAvg) calculated for that cross-sectional CT image. Analysis of variance showed that the left posterolateral segments in expanding AAAs had larger Rc/RcAvg ratios than those segments in stable AAAs (1.14 +/- 0.19 vs. 0.80 +/- 0.09, p < 0.02). Laplace's law indicates that the left posterolateral segment in AAAs that grow more rapidly is subjected to greater wall tension. Flattening in the curvature of the left posterolateral wall segment was significantly associated with an increased rate of expansion in small AAAs. This finding, readily derived from standard CT scan images, may predict which small AAAs are more prone to rapid expansion.

Thromboembolic complications of polycythemia: polycythemia vera versus smokers' polycythemia.

PURPOSE: This report compares patients with the hypercoagulable state of polycythemia vera to patients with secondary polycythemia caused by tobacco use to determine whether the incidence of thromboembolic events is equivalent. METHODS: The medical records of 146 patients with the diagnosis of polycythemia between 1977 to 1990 were reviewed. Patients with transient, relative, or stress polycythemia were excluded from this study as were patients with polycythemia as a result of cardiac or pulmonary anomalies or both. The diagnosis of polycythemia vera (n = 43) was verified by use of the guidelines of the Polycythemia Vera Study Group. The diagnosis of polycythemia caused by smoking (n = 27) was based on an elevated total red blood cell volume, decreased oxygen saturation on arterial blood gas measurement, evidence of chronic obstructive pulmonary disease, and elevated carboxyhemoglobin levels. RESULTS: Twenty-six patients (60%) with polycythemia vera and 11 patients (41%) with smoker's polycythemia had at least one thromboembolic problem. No significant differences existed between the groups with regard to age, hematocrit, or number of cardiac and cerebrovascular events. Overall, patients with polycythemia vera had a greater number of thromboembolic events per patient (p < 0.05) and more peripheral arterial thromboemboli (p < 0.005) than did patients with polycythemia as a result of smoking (Fisher's Exact Test). CONCLUSIONS: Thus the results of this study demonstrate that smokers' polycythemia does not represent a hypercoagulable state equivalent to that of polycythemia vera.

Recognition of arterial injury in elbow dislocation.

The clinical presentation of patients with elbow dislocations was reviewed to identify those factors indicating an increased risk for arterial injury. Sixty-two patients were treated for 63 elbow dislocations between January 1981 and July 1991. Eight patients (13%) sustained a concomitant arterial injury involving the brachial (7) and radial (1) arteries. Three clinical findings, absence of a radial pulse, open dislocation, and presence of systemic injuries, were correlated with arterial injury. A palpable radial pulse was absent in six (75%) patients with an arterial injury but in only two (4%) with normal vessels (p less than 0.0001, chi square). Five (33%) open dislocations had an associated arterial injury, whereas three (6%) arterial injuries occurred in closed dislocations (p less than 0.006, chi square). Systemic injury occurred in five dislocations (63%) with arterial injuries and 14 dislocations (25%) without arterial injury (p less than 0.04, chi square). Multivariate analysis showed that absence of a radial pulse was the only factor that significantly predicted arterial injury (p less than 0.0001). Although most elbow dislocations are not associated with arterial injury, absence of a radial pulse or presence of an open dislocation or both should alert the clinician to the increased possibility of an associated vascular injury.

Trauma to the proximal superior mesenteric artery: a case report and review of the literature.

Visceral arterial injuries account for a small but important portion of major abdominal vascular trauma. A case of proximal superior mesenteric artery trauma is presented. The advantages and drawbacks of the surgical approaches to these injuries are discussed. On the basis of a review of the literature describing the management of these injuries, ligation of the proximal superior mesenteric artery for trauma cannot be recommended. Prompt surgical intervention with revascularization offers the best chance for the survival of these critically injured patients.

Hip disarticulation: factors affecting outcome.

Hip disarticulation, especially in patients with peripheral vascular disease, has been associated with high morbidity and mortality rates. This report describes patient characteristics that influence the clinical outcome of hip disarticulation. The medical records of all patients undergoing hip disarticulation from 1966 to 1989 were reviewed for surgical indication, perioperative wound complications, and postoperative deaths. Fifty-three patients underwent hip disarticulation for limb ischemia (10), infection (12), infection and ischemia (14), or tumor (17). The overall incidence of wound complications was 60%, and no significant differences were found among the groups. Prior above-knee amputation and urgent/emergent operations were significantly associated with increased wound complications (p less than 0.05). The overall mortality rate was 21%, ranging from 0% (tumor) to 50% (ischemia) and differed significantly among the groups (p less than 0.02). Mortality was significantly associated with urgent/emergent operations (p less than 0.01). Age, diabetes mellitus, and previous inflow procedures did not influence mortality rates. The presence of limb ischemia influenced mortality rates to a greater extent than did infection, and a history of cardiac disease was statistically predictive of death. Wound complications frequently accompanied hip disarticulation, regardless of operative indication, and were significantly increased by urgent/emergent operations and prior above-knee amputation. Hip disarticulation can be performed with low mortality rates in selected patients. Both limb ischemia and infection substantially increase operative mortality rates.

Thallium redistribution does not predict perioperative cardiac complications following vascular surgery.

Utility of preoperative stress thallium scintigraphy (STS) was determined in 59 patients, thought to be at increased risk, prior to major vascular surgery from July 1987 to February 1990. Forty-seven had oral dipyridamole and 12 underwent exercise STS. Thallium redistribution (TR) was present in 61% (n = 36); fixed defects were present in 59% (n = 35); and some combination of defects was present in 76% (n = 45). Perioperative cardiac complications (CC = congestive heart failure [n = 3], ventricular arrhythmia [n = 2], and MI [n = 1]) were present in 8.5% (6 CC in 5 patients). Incidence of CC was 8.3% (3/36) in those with TR, and 8.7% (2/23) without TR (relative risk = 0.95). Perioperative MI was present in 2.8% (1/36) with TR vs. 0% (0/23) without. Though mortality was 3.4%, no perioperative deaths were from cardiac disease. Utility of STS is not clearly established for prediction of perioperative cardiac risk after major vascular surgery.

Effects of atherosclerosis on the cutaneous regional and microcirculatory response to ischemia.

The cutaneous vascular response to gravity load is abnormal in atherosclerosis. In this study we compared the macrocirculatory and microcirculatory response to ischemia in atherosclerotic smokers, nonatherosclerotic smokers, and healthy nonsmokers. Using videodensitometry, the capillary blood velocity of hallux nail fold capillaries was measured at rest and following 1 minute of ankle cuff occlusion. Blood-flow velocity of the dorsal metatarsal artery was measured by ultrasound Doppler. Resting dorsal metatarsal artery velocity and capillary blood velocity of atherosclerotic subjects were lower than those of nonatherosclerotic smokers and nonsmokers. The dorsal metatarsal artery velocity and capillary blood velocity increased in each group following occlusion. Peak postocclusion dorsal metatarsal artery velocity was lower in the atherosclerotic subjects, but peak capillary blood velocity was not significantly different among groups. Atherosclerosis does not alter the mechanisms of reactive hyperemia in either the macrocirculation or the microcirculation. The magnitude of hyperemia is diminished at the macrocirculatory level.

Failure of pentoxifylline to enhance skin flap survival in the rat.

The effect of pentoxifylline, a hemorheological agent that increases erythrocyte flexibility and augments capillary blood flow, on the survival of the dorsal skin flap of the rat was studied. An experimental group received intraperitoneal injections of pentoxifylline twice daily, 50 mg/kg/day, and a control group was given identical volumes of saline. Standard McFarlane flaps sized 4 x 9 cm (n = 22) and narrower 2 x 6-cm flaps (n = 18) were constructed 14 days later. After a postoperative observation period of 7 days, no significant difference in tissue survival between the pentoxifylline-treated animals and the controls was found in either flap model. Fourteen days preoperative treatment with pentoxifylline appeared to have no effect on flap survival.

Pentoxifylline increases extremity blood flow in diabetic atherosclerotic patients.

Pentoxifylline, a new trisubstituted methylxanthine derivative known for its hemorrheologic action, has been shown to improve exercise tolerance in atherosclerotic patients. We examined the responses of diabetic atherosclerotic patients to pentoxifylline administration, measured by Doppler waveform analysis and exercise tolerance. Standard exercise tolerance and Doppler waveform analytic studies of the lower extremity, specifically the right dorsalis pedis artery, were performed before and after three months of pentoxifylline administration (400 mg three times a day). The study group comprised ten subjects (six men and four women) with a mean (+/- SD) age of 60 +/- 3.3 years. Data were analyzed using a paired Student t test. All ten subjects showed a significant increase in exercise tolerance after pentoxifylline treatment. Eight of ten subjects demonstrated a significant increase in right dorsalis pedis arterial flow.

Jugular-axillary vein bypass for salvage of arteriovenous access.

Stenosis or occlusion of the subclavian vein can cause incapacitating upper extremity swelling and venous hypertension in the patient with an arteriovenous (AV) access. A case of subclavian vein occlusion is reported that was treated with internal jugular-axillary vein bypass. This procedure resulted in salvage of the access and rapid resolution of the associated upper extremity swelling. It was concluded that jugular-axillary vein bypass should be considered in patients who have massive upper extremity edema resulting from a functioning AV access and ipsilateral subclavian vein occlusion. Patients undergoing creation of an AV access who have had previous temporary subclavian catheters or previous early failure of an AV access should have phlebography before surgery.