Biomedical subjects

P F Lawrence

Publications and source records attributed to P F Lawrence.

At least 19 recordsLinked to original sources

PubMed2001

Wound infections involving infrainguinal autogenous vein grafts: a current evaluation of factors determining successful graft preservation.

PURPOSE: The purpose of this study was to review the natural history and clinical outcome of patients with infrainguinal autogenous graft infection (IAGI), to evaluate the effectiveness of attempted graft preservation, to determine those variables associated with graft salvage, and to better determine optimal treatment. STUDY DESIGN: We retrospectively reviewed the records of patients undergoing infrageniculate vein grafts at three hospitals between 1994 and 2000 who had a wound infection involving the graft. Clinical and bacteriologic variables were analyzed and correlated with graft salvage, limb salvage, and clinical outcome. RESULTS: During this 7-year period, 487 patients underwent an infrageniculate vein graft, and 68 (13%) had clinical evidence of IAGI. Twenty-seven patients presented with drainage from the wound, 15 with wound separation and cellulitis, 18 with soft tissue infection extending to the graft, 4 with an abscess and cellulitis, and 4 with bleeding. Ten patients (15%) had systemic symptoms (defined as a white blood cell count > 15,000 and temperature > 38.5 degrees C). Forty infections developed in the thigh, 17 in the groin, and 11 in the lower leg. An anastomosis was exposed in 15 patients. Wound cultures were positive for bacteria in 52 patients, and most infections were due to Staphylococcus aureus (18 patients) and S epidermidis (12 patients). Pseudomonas was cultured from seven infections. Twelve patients had polymicrobial infections. The interval from operation to infection ranged from 7 to 180 days. All patients were treated with oral antibiotics, 48 after intravenous antibiotics. Forty-five patients had operative debridement, including 18 who had muscle flap coverage. Four patients presented with hemorrhage, and three had immediate graft ligation and one graft excision. Follow-up ranged from 5 to 68 months (mean, 24.3 months), with 61 patients currently alive. Two patients died as a result of the IAGI (mortality rate, 2.9%). One had undergone a below-knee amputation, and one had a nonhealed wound but intact limb. Overall, 61 wounds (91%) healed, 4 patients required below-knee amputations, and 3 wounds did not heal. Fifty-eight grafts remained patent, 6 thrombosed, and 4 were ligated to control hemorrhage. Of the 61 wounds that healed, the time required for healing ranged from 7 to 63 days. No patient with bleeding died because of the acute episode. No patient had delayed hemorrhage. All 18 patients treated with a muscle flap healed. Bleeding (P <.001), elevated white blood cell count (P <.029), fever (P <.001), and renal insufficiency (creatinine level > 1.5; P <.056) were the only variables statistically significant in predicting graft failure or limb loss. With the use of life-table analysis, graft patency was 94%, 72%, and 72% at 1, 3, and 5 years, and limb salvage was 97%, 92%, and 92% at the same intervals, respectively. CONCLUSIONS: Most patients with an IAGI can be successfully treated with graft and limb preservation. In contrast to earlier studies, an exposed anastomosis, interval to infection, or Pseudomonas infection is not associated with graft failure. Graft salvage is less likely in patinets with fever, leukocytosis, and renal insufficency, but because most grafts remained patent, graft preservation is recommended for these patients. Graft ligation or excision should be reserved for patients presenting with bleeding or sepsis.

Amputation, Surgical↗

PubMed2000

Autogenous arterial bypass grafts: durable patency and limb salvage in patients with inframalleolar occlusive disease and end-stage renal disease.

OBJECTIVE: The purposes of this study were to determine whether autogenous arterial grafts to distal pedal arteries improve the patency of grafts and limb salvage in patients with end-stage renal disease and nonhealing ischemic wounds and to better define the indications for autogenous arterial grafts. DESIGN: A review of consecutive patients with end-stage renal disease undergoing autogenous arterial grafts from 1994 through 1999 was carried out. The setting was a university hospital. All 11 patients with end-stage renal disease and nonhealing, ischemic wounds (stage IV SVS-ISCVS classification) undergoing autogenous arterial grafting from 1994 to 1999 were evaluated. Noninvasive studies confirmed inadequate perfusion pressures in all patients. Pre-bypass arteriography identified no major arteries patent at the level of the malleolus, with reconstitution of only a distal or branch pedal or plantar vessel less than 1 mm in diameter. Five patients with patent tibial vessels to just above the ankle underwent bypass surgery with autogenous arterial grafts alone. Six patients also had proximal occlusive disease that required grafts longer than the autogenous arterial grafts; in each of these six patients, an autogenous vein graft proximal to the autogenous arterial graft was placed through use of a composite technique. Inflow was from the common femoral artery in one patient, the popliteal artery in five patients, and a tibial artery in five patients. Outflow was to the medial plantar artery in five patients, the distal dorsalis pedis artery in three patients, the lateral plantar artery in two patients, and the superficial arch in one patient. The conduit was the subscapular artery in four patients, the deep inferior epigastric artery in four patients, the superficial inferior epigastric artery in two patients, and the radial artery in one patient. The main outcome measures were assisted primary graft patency and functional limb salvage rate. RESULTS: Follow-up ranged from 6 to 63 months (mean, 20 months); graft patency was determined by means of duplex scanning. All 11 patients are alive, and nine grafts are patent, including three after revision for graft stenosis. Assisted primary patency was 82% at 3 years. All nine patients with patent grafts remained ambulatory and had healed wounds or limited forefoot amputations. CONCLUSION: Autogenous arterial grafts were effective in treating limb-threatening ischemia in patients with end-stage renal disease and inframalleolar arterial insufficiency. Graft patency and limb salvage rates were higher than those reported for autogenous vein graft in these patients. Autogenous arterial grafting may therefore prove to be an effective alternative to autogenous vein grafting in selected patients.

Arterial Occlusive Diseases↗

PubMed2000

Incidentally detected stenoses proximal to grafts originating below the common femoral artery: do they affect graft patency or warrant repair in asymptomatic patients?

OBJECTIVE: Stenoses in infrageniculate arteries proximal to a lower extremity vein graft may reduce flow velocity through the bypass graft and are thought to predispose to graft occlusion. Repair of these lesions has been recommended to preserve graft function. This study was undertaken to better define the natural history of grafts below inflow lesions and to evaluate the necessity of repair to preserve graft patency. METHODS: From 1994 through 1999, patients undergoing lower extremity vein grafts by a single surgeon at a university hospital and an affiliated teaching hospital were placed in a prospective protocol for proximal infrageniculate native artery and graft surveillance through use of duplex scanning. The records of those patients with grafts originating distal to the common femoral artery were evaluated; they form the basis for this report. Arteriograms were obtained before bypass grafting, and no patient had a stenosis greater than 50% diameter reduction proximal to the graft origin. Follow-up scans were obtained from the common femoral artery through the graft and outflow artery. The peak systolic velocity and velocity ratio in an infrageniculate native artery proximal to the graft origin were recorded, as were the location and the time interval since the bypass graft. Repair of these proximal lesions was not performed during the course of this study. Revision of the bypass graft or its anastomoses was undertaken according to preestablished duplex scan criteria. RESULTS: During this time, 288 autogenous infrainguinal bypass grafts were performed, of which 159 originated below the common femoral artery; of these, 74 were from the superficial femoral artery, 29 from the profunda femoris artery, 49 from the popliteal artery, and 7 from a tibial artery. The maximum peak systolic velocity proximal to the graft origin was more than 250 in 38 arteries (25%) and more than 300 in 26 arteries (16%). The velocity ratio was 3.0 or more in 32 arteries at the same location as the peak systolic velocity and 3.5 or more in 23 arteries (15%), confirming hemodynamically significant stenoses at these sites. The location of peak systolic velocity was the common femoral artery in 81 patients (51%), the superficial femoral artery in 50 (31%), the popliteal artery in 22 (14%), and a tibial artery in 6 (4%). Follow-up ranged from 8 to 60 months (mean, 35 months). During follow-up, 19 patients died, 18 with patent grafts. Overall, nine grafts occluded. One of the occluded grafts had a velocity ratio greater than 3.0; this may have contributed to graft thrombosis. The other occlusions resulted from an unrepaired graft lesion in 2 patients, graft infection in 2 patients, and graft ligation necessitated by below-knee amputation in 2 patients. No cause for the occlusion could be identified in two of the grafts (neither had evidence of proximal arterial stenosis). Assisted primary patency rates were 95% and 91% at 3 and 5 years, respectively. CONCLUSIONS: For grafts originating distal to the common femoral artery, stenoses proximal to the graft do not affect bypass graft patency and do not require repair to prevent graft occlusion. Surveillance of these lesions may therefore be unnecessary, inasmuch as the repair of proximal lesions should not be undertaken to preserve graft function.

Adult↗

PubMed1999

The epidemiology of surgically repaired aneurysms in the United States.

OBJECTIVE: The purpose of this study was to determine the results of surgery for hospitalized cases of aneurysms in the United States, thereby providing a standard of comparison for new techniques proposed to treat aneurysms. METHODS: Data on hospitalized aneurysm cases were collected from the National Hospital Discharge Survey, a comprehensive database of patients hospitalized in the United States for treatment from the years 1984 to 1994. The National Hospital Discharge Survey samples non-federal, acute-care hospitals with an average length of stay of less than 30 days. All the cases had a diagnosis of or a surgical procedure for a non-cerebral aneurysm. RESULTS: In the year 1994, 51,949 non-cerebral aneurysms were repaired in the United States, and 75% of these procedures were abdominal aortic aneurysm (AAA) surgeries. The operative mortality rates for AAA were higher than previously reported from multi-institutional studies and were found to be 8.4% for elective repair and 68% for emergency AAA repair. The number of aneurysm surgeries per thousand population varied by region: surgery rates were more frequent in the Northeast and less frequent in the West. Surgical volume appeared to decrease for smaller hospitals and increase for larger hospitals for the period between 1990 and 1994. The overall mortality rates for all aneurysm surgeries diminished with hospital size. However, no significant difference was found for the rates of elective AAA repair between hospital sizes. The percentage of men with aneurysms who underwent surgery for repair was significantly higher than for women with aneurysms. In addition, the AAA repair rates increased for men from 1985 to 1994, and the number of women reported with repaired AAAs remained constant. CONCLUSION: The location of aneurysm, urgency of repair, region, sex, and hospital size are important factors related to patient treatment and outcome. These data provide a standard of comparison against which surgeons can compare their own results, and they provide a benchmark for the evaluation of interventional techniques proposed to treat aneurysms.

Aged↗

PubMed1999

Effect of outflow level and maximum graft diameter on the velocity parameters of reversed vein bypass grafts.

OBJECTIVE: The objective of this study was to define a normal range of distal graft velocity (DGV) and peak systolic velocity (PSV) on the basis of outflow level and maximum graft diameter for infrainguinal reversed vein bypass grafting (RVG). METHODS: This study was designed as a prospective study of consecutive patients who underwent infrainguinal RVG from 1994 to 1997 in a university hospital and university-affiliated teaching hospital. All patients who underwent infrainguinal bypass grafting from 1994 to 1997 were placed in a prospective protocol with duplex scanning to better define the hemodynamics of normally functioning RVG. Graft revisions were performed for patients with velocity ratios of more than 2.5. One hundred twenty-one patients were entered into this protocol, and 114 were followed more than 3 months after RVG. Seven patients were excluded: five for death within 3 months, one for graft infection, and one for graft occlusion before the baseline duplex scanning. DGV and PSV were determined for each type of outflow (popliteal, crural, and pedal) and for ranges of maximum graft diameter. These then were correlated with subsequent graft occlusion or graft revision (graft failure). RESULTS: Grafts with larger diameters were associated with lower DGVs (P <.001), and more proximal outflow arteries were associated with higher DGVs (popliteal, 75 cm/s; crural, 50 cm/s; and pedal, 40 cm/s; P <.01). The mean PSVs were 150, 140, and 122 cm/s for popliteal, crural, and pedal grafts, respectively, but the difference was not statistically significant. The assisted primary patency rates for the grafts in this series were 99%, 92%, and 92% at 1, 2, and 3 years. CONCLUSION: Graft diameter and location of the distal anastomosis significantly affect the flow velocity in RVG. Other variables did not influence these parameters. Currently established criteria for arteriography or graft repair on the basis of graft velocity parameters may be improved if they can be modified depending on diameter and outflow.

Aged↗

PubMed1999

An assessment of the current applicability of the EVT endovascular graft for treatment of patients with an infrarenal abdominal aortic aneurysm.

OBJECTIVE: To determine the percentage of elective abdominal aortic aneurysms (AAAs)/aortoiliac aneurysms that currently can be repaired with endovascular grafts (EVGs), the reasons for rejection of EVGs, and the future role of EVG in the treatment of AAA. METHODS: From January 1997 to May 1998, patients at three hospitals (a university hospital, a university-affiliated teaching hospital, and a Veterans Administration hospital with university faculty and residents) were evaluated for EVGs as part of a national clinical trial with grafts manufactured by Endovascular Technologies (EVT, Menlo Park, Calif). All patients at two hospitals and patients treated by the participating surgeons at the third hospital were screened for EVG. Patients with AAAs that were ruptured, symptomatic, or involved renal or mesenteric arteries and patients who declined treatment were excluded from the study. Evaluation included clinical examination, computed tomography scan, and selective arteriography. The decision to proceed with EVG was made by the vascular surgeon, with input and concurrence of medical personnel from a company with extensive experience in endograft repair. The main outcome measures were the determination of the percentage of elective AAAs currently being treated with an EVG and the reasons for exclusion of patients from EVG placement. RESULTS: A total of 162 patients underwent elective treatment of an AAA, 22 (14%) with an EVG (14 bifurcated, eight tube) and 140 (86%) with traditional resection. Indications for not proceeding with an EVG included insufficient proximal cuff in 29 patients (21%), distal common iliac aneurysm or insufficient distal iliac neck in 29 patients (21%), proximal neck too large for an EVG in 24 patients (17%), symptomatic iliac stenosis in 23 patients (16%), iliac stenosis precluding introducer passage in 17 patients (12%), patient preference in 11 patients (8%), and calcification, kink, or extensive thrombus involving the proximal neck precluding safe graft attachment in seven patients (5%). Of the 22 patients treated with an EVG, three were converted to open resection, because of iliac stenosis in two patients and premature stent deployment in one patient (initial technical success rate, 86%). CONCLUSION: Based on currently available technology, 80% of patients were not candidates for an EVG because of proximal calcification, short aortic or distal cuff, coexisting distal iliac aneurysm, and stenotic iliac disease. Even with the use of adjunctive procedures, most patients still require open repair. Significant changes in design will be necessary to apply these devices to most patients with an AAA.

Aortic Aneurysm, Abdominal↗

PubMed1999

Left subclavian artery aneurysm: two cases of rare congenital etiology.

Subclavian artery aneurysms are uncommon. The most common causes of these aneurysms are atherosclerosis and traumatic pseudoaneurysm. We report two cases of rare congenial left subclavian artery aneurysms. Diagnosis with aortography and treatment with resection with bypass grafting are the optimal approaches to avoid life-threatening and limb-threatening ischemia.

Adult↗

PubMed1998

Peripheral aneurysms and arteriomegaly: is there a familial pattern?

PURPOSE: Studies have shown that 11% to 18% of patients with an abdominal aortic aneurysm (AAA) have a first-degree relative with an AAA. A familial pattern among patients with peripheral arterial aneurysms and arteriomegaly has not been reported. The objective of this study was to examine familial patterns among patients with peripheral arterial aneurysm and arteriomegaly and compare them with patterns among patients with AAA. METHODS: Pedigrees were constructed for first-degree relatives of patients who received the diagnosis of peripheral arterial aneurysm, arteriomegaly, or AAA from 1988 through 1996. The presence of aneurysms and risk factors was confirmed for patients and relatives by means of telephone interviews and review of hospital and physician records. RESULTS: Seven hundred three first-degree relatives older than 50 years were contacted for 140 probands with peripheral arterial aneurysm, AAA, or arteriomegaly. There were differences in risk factors for hernia and diabetes mellitus among the probands with peripheral arterial aneurysm, AAA, or arteriomegaly but none for relatives. Patients with peripheral arterial aneurysm (n = 40) had a 10% (4/40) familial incidence rate of an aneurysm, patients with AAA (n = 86) had a 22% (19/86) familial incidence rate, and patients with arteriomegaly (n = 14) had a 36% (5/14) familial incidence rate. AAA (24/28, or 86%) was the aneurysm diagnosed most commonly among first-degree relatives. Most aneurysms (85%) occurred among men. CONCLUSION: There appears to be a gradation of familial patterns from peripheral arterial aneurysm to AAA to arteriomegaly among patients with degenerative aneurysmal disease, and there appears to be a predominance among men. Relatives of patients with any of the 3 lesions-peripheral arterial aneurysm, AAA, arteriomegaly--most frequently have AAA. Relatives of patients with AAA, peripheral arterial aneurysm, or arteriomegaly may be screened by means of a physical examination for peripheral aneurysmal disease. Screening by means of ultrasound examination of the aorta should be limited to first-degree relatives of patients with aortic aneurysms or arteriomegaly.

Aged↗

PubMed1998

Does stent placement improve the results of ineffective or complicated iliac artery angioplasty?

OBJECTIVE: This study was undertaken to determine the results and complications of stents placed for initially unsuccessful or complicated iliac percutaneous transluminal angioplasty (PTA), the effect of location (external iliac or common iliac) on outcome, and the influence of superficial femoral artery patency on benefit. DESIGN: From 1992 through 1997, 350 patients underwent iliac artery PTA at the authors' institutions. Of this group, 88 patients (88 arteries) had one or more stents placed after PTA (140 stents in total) for residual stenosis or pressure gradient (63 patients), iliac dissection (12 patients), long-segment occlusion (10 patients), or recurrent stenosis (3 patients). Thirty patients required the placement of more than one stent. The indications for PTA in these 88 patients were claudication (48 patients) and limb-threatening ischemia (40 patients). Forty-seven patients had stents placed in the common iliac, 29 patients had stents placed in the external iliac, and 12 patients had stents placed in both. Seventy-one arteries (81%) were stenotic, and 17 (19%) were occluded before PTA. Sixty-six arteries were treated by interventional radiologists, 15 by a vascular surgeon, and 7 jointly. MAIN OUTCOME MEASURE: Criteria for success included (1) increase of at least one clinical category of chronic limb ischemia from baseline or satisfactory wound healing, (2) maintenance of an ankle/brachial index increase of more than 0.10 above the preprocedure index, and (3) residual angiographic stenosis less than 25% and, for patients with pressure gradient measurements, a residual gradient less than 10 mm Hg. RESULTS: Stent placement was accomplished in all 88 patients with 16 (18%) major complications. Mean follow-up was 17 months (range, 3 to 48 months). By life-table analysis, success was 75% at 1 year, 62% at 2 years, and 57% at 3 years. No cardiovascular risk factor or independent variable was statistically significant in predicting success. There was no difference in success rates for common iliac or external iliac lesions. Superficial femoral artery patency did not correlate with outcome. CONCLUSIONS: Although stents can eliminate residual lesions and arterial dissection, these patients are likely to require adjuvant or subsequent procedures to attain clinical success. By controlling the PTA complication and treating the emergent problem, stents may allow for subsequent elective intervention.

Adult↗

PubMed1998

Incidence, timing, and causes of cerebral ischemia during carotid endarterectomy with regional anesthesia.

PURPOSE: Controversy exists regarding the best technique to identify cerebral ischemia during carotid endarterectomy (CEA). Regional anesthesia allows continuous evaluation of neurologic function and therefore can help determine the incidence, timing, and causes of cerebral ischemia. METHODS: The timing and clinical manifestations of any neurologic event during CEA and as long as 30 days afterward was determined by review of operative reports, hospital charts, and outpatient records of consecutive patients who underwent CEA under regional anesthesia over a 68-month period. RESULTS: Two hundred patients underwent CEA; indications were asymptomatic stenosis > 60% in 25%, transient ischemic attack with stenosis > 50% in 52%, and prior stroke with stenosis > 50% in 23%. Eight patients (4%) were converted to general anesthesia for non-ischemic reasons. Of the remaining 192 patients, 183 (95.5%) underwent the procedure with regional anesthesia and no shunt, 2% had cerebral ischemia and underwent shunt placement, and 2.5% had cerebral ischemia, were converted to general anesthesia, and underwent shunt placement. Cerebral ischemia developed in nine patients after carotid cross-clamping, manifested by loss of consciousness in four, confusion in two, dysarthria and confusion in one, and decreased contralateral motor strength in two. Immediate cerebral ischemia developed in four of the nine patients within 1 minute of cross-damping; all four underwent shunt placement. In five of the nine patients, cerebral ischemia occurred between 20 and 30 minutes after cross-clamping; all occurred during relative intraoperative hypotension (average reduction of 35 mm Hg in the systolic pressure). All awake patients in whom ischemic symptoms developed immediately regained and maintained normal neurologic function with shunt placement. Five of 26 patients (19%) with contralateral occlusion required a shunt; none had postoperative ischemia. The mean carotid cross-clamp time was 27 minutes. Postoperative (30 day) complications included a 0.5% stroke rate, a 0.5% rate of postoperative transient ischemic attack, a 0.5% rate of worsening of preexisting acute stroke, and a 0.5% rate of myocardial infarction (no deaths). Of the nine patients who had intraoperative ischemic changes, none had a postoperative neurologic deficit; the three patients who had postoperative neurologic changes had no intraoperative ischemic symptoms. CONCLUSIONS: CEA with regional anesthesia allows continuous neurologic monitoring and can be performed safely even when contralateral occlusion coexists; intraoperative shunting for ischemia is necessary in 4.5% of all cases and in 19% of patients with contralateral occlusion. Intraoperative ischemia was flow-related in our patients; it occurred early from ipsilateral carotid clamping and late from reduced collateral flow as a result of hypotension. Monitoring should be continued throughout cross-clamping to identify late cerebral ischemia. Postoperative cerebral ischemia is not associated with intraoperative ischemia, if corrected.

Aged↗

PubMed1997

Safety, feasibility, and early efficacy of subfascial endoscopic perforator surgery: a preliminary report from the North American registry.

PURPOSE: The North American Subfascial Endoscopic Perforator Surgery (NASEPS) Registry was established to evaluate the safety, feasibility, and efficacy of minimally invasive endoscopic Linton operations for treatment of chronic venous insufficiency. METHODS: Retrospective analysis was performed on the clinical data of 151 patients who underwent attempt at 158 SEPS in 17 medical centers in the United States and Canada between June 1993 and February 1996. RESULTS: SEPS was completed on 155 limbs of 148 patients, 81 male and 67 female (mean age, 56 years; range, 27 to 87 years). Three procedures were aborted. Seven patients had bilateral procedures (data from one limb were analyzed). One hundred four limbs (70%) had active ulcers, and 22 (15%) had healed ulcers. A single endoscopic port without insufflation was used in 66 procedures (45%) and laparoscopic instrumentation, with two or three ports, in 82 (55%), with CO2 insufflation in 78 (53%). A tourniquet was used on 112 patients (76%). Concomitant venous procedures were performed in 106 patients (72%; saphenous stripping in 71, high ligation in 17, varicosity avulsion in 85). No early deaths or thromboembolism occurred. Complications included wound infections (9), superficial thrombophlebitis (5), cellulitis (4), and saphenous neuralgia (10). Seven patients with wound infection had open ulcers; nine of 10 with neuralgia had concomitant procedures. A roll-on tourniquet caused skin necrosis in one patient. The clinical score improved from 9.4 to 2.9 after surgery (p < 0.0001). Mean follow-up was 5.4 months; 31 patients had > or = 6 months follow-up. Ulcers healed in 88% (75 of 85); recurrence or new ulcer was reported in 3% (4 of 120). CONCLUSIONS: The SEPS modified Linton operation appears safe, with no postoperative deaths or early thromboembolism. Wound infection after SEPS remains important. Early results indicate rapid ulcer healing. Prospective evaluation of long-term results is warranted.

Adult↗

PubMed1997

Revision of reversed infrainguinal bypass grafts without preoperative arteriography.

PURPOSE: To determine whether graft revision on the basis of a duplex scan alone without an arteriogram is effective in identifying graft stenosis and allowing for repair to preserve bypass graft patency. METHODS: From 1994 to 1997, all patients in whom infrainguinal grafts were placed at a University-affiliated teaching hospital were entered into a prospective protocol using duplex scanning to detect stenotic lesions. Studies were performed after the operation, at 1 month, at 3 months, and every 3 months thereafter. All grafts were composed of reversed autogenous vein and were placed subcutaneously to allow for easier monitoring and correction. Patients who had failing grafts underwent operative correction without preoperative arteriography. RESULTS: During this interval, 48 lesions in 31 grafts were repaired. The indication for repair was a velocity ratio greater than 2.5 in all patients and greater than 3.0 for 43 lesions. Forty-four lesions had a peak systolic velocity greater than 250 cm/sec. Twenty-nine lesions reduced the distal graft velocity to less than 45 cm/sec. Sixteen lesions involved the proximal anastomosis, 26 the body of the graft, three the distal anastomosis, two involved inflow arteries, and one affected the outflow vessel. Repair included patch angioplasty for 39 lesions, resection with interposition graft for five, a proximal jump graft for three, and a distal extension graft for one. The severity and location of the stenosis was confirmed at operation in all cases. Twenty-eight of the 31 patients (90%) are currently alive, and follow-up on these patients has ranged from 5 to 36 months (mean, 19 months). Twenty-nine of the 31 grafts (94%) remained patent, with a 92% patency rate by life table analysis at 3 years. Follow-up duplex scans found improvement in the ankle-brachial index (mean increase, 0.33) and distal graft velocity (mean increase, 43 cm/sec) in all patients. After repair, 27 patients had a distal graft velocity greater than 45 cm/sec and no patient had a velocity ratio greater than 1.5. Complications included wound infection in two patients and bleeding that required reoperation in one. All symptomatic patients had clinical improvement, and none required early reexploration for residual stenosis. CONCLUSIONS: Graft repair may be safely performed on the basis of duplex scanning alone with preservation of bypass patency and correction of hemodynamic deterioration. Duplex scanning can detect inflow or outflow disease in addition to intrinsic graft stenoses and can identify sequential lesions, eliminating the need for, expense of, and risk of arteriography.

Aged↗

PubMed1995

Management of infected aortic grafts.

Aortic graft infection will continue to occur in a small proportion of patients who undergo reconstructive aortic surgery. For most patients, the standard approach should use extra-anatomic bypass, followed by complete excision of the graft, as the treatment of choice. However, in selected patients who have localized infection, are high risk surgical candidates, or have grafts located in positions that preclude removal, less aggressive alternatives such as topical antibiotic irrigation, graft resection with debridement and replacement, and in situ replacement with a biologic graft take an increasing role. When prosthetic grafts are developed that are less susceptible to reinfection, owing to incorporation of antibiotics into the graft, in situ replacement may become the treatment of choice. In spite of many advances in the management of aortic graft infection, this complication continues to carry a high mortality and amputation rate, and consequently should be managed by surgeons who have a particular interest and experience in managing this particular problem. With a thorough understanding of the circumstances of the original operation, bacteria infecting the graft, extent of graft infection, and management alternatives, most patients can survive prosthetic aortic graft infections with a combined morbidity and mortality of less than 50%.

Aorta↗

PubMed1995

The incidence of iliac, femoral, and popliteal artery aneurysms in hospitalized patients.

PURPOSE: Previous studies have attempted to determine the incidence and mortality rate of abdominal aortic aneurysms in a variety of populations; however, the incidence of iliac, femoral, and popliteal artery aneurysms have not been established. The objective of this study was to determine the incidence of lower extremity aneurysms in hospitalized patients in the state of Utah, which has a population at low risk for cardiovascular disease, atherosclerosis, and smoking, and to compare the results with the incidence in the United States. METHODS: Incidences of iliac, femoral, and popliteal artery aneurysm in Utah were determined over a 6-year period, with data obtained via diagnostic codes from the Utah Hospital Association. The incidence of iliac, femoral, and popliteal artery aneurysms in the United States hospital population was calculated by use of National Hospital Discharge Summary 1990 data, a complex sample of nonfederal short-stay hospitals in the United States, which provides the most comprehensive database of health statistics in the United States. RESULTS: The incidence of iliac femoral/popliteal artery aneurysms in hospitalized Utah men is 3.76 and 4.85 per 100,000 population, respectively. In American men, iliac and femoral/popliteal artery aneurysm incidences are 6.58 and 7.39 per 100,000 population, respectively. Incidences among hospitalized women in Utah are 0.24 and 1.07 per 100,000; incidences in women in the United States are 0.26 and 1.00 per 100,000, respectively. The incidence of nonaortic peripheral aneurysms among hospitalized patients in Utah is lower than in the United States. The rate ratios (Utah/United States) for incidences of iliac, femoral, and popliteal artery aneurysms in men are 0.57 and 0.66, respectively (p < 0.05). No statistical difference is seen between incidences in women in Utah and the United States (p > 0.05)-ratios of 0.93 and 1.06, respectively. CONCLUSION: This study validates the traditional belief that iliac, femoral, and popliteal artery aneurysms are much less frequent, at least in hospitalized patients, than previously published incidences of abdominal aortic aneurysms.

Adult↗

PubMed1993

Thrombolytic therapy in an isolated limb.

Intraoperative thrombolytic therapy is a useful adjunct to balloon catheter thromboembolectomy for treatment of acute embolism or thrombosis, but the technique is frequently limited by incomplete thrombolysis and systemic hemorrhage. In an attempt to improve results and reduce complications of conventional thrombolytic therapy, urokinase was infused into a limb that was isolated with a tourniquet. This isolated limb perfusion technique was initially developed in an animal model and subsequently used for limb salvage in patients who failed thromboembolectomy. The animal model demonstrated that a fibrinolytic state could be achieved and isolated to the extremity, even when using extremely high dose (20,000 to 50,000 IU/kg) of thrombolytic agents. The fibrinogen level was unmeasurable and the prothrombin, partial thromboplastin, and thrombin times were significantly prolonged in the isolated limb (p < 0.001), whereas no changes occurred in these parameters in the systemic circulation. In seven patients, streptokinase (27,000 to 200,000 IU) and urokinase (150,000 to 300,000 IU) were infused into isolated extremities after thrombectomy alone had failed to restore blood flow. All extremities showed improved perfusion after thrombolytic therapy and five remained viable 6 months after treatment. There were no systemic bleeding complications despite two patients having undergone major operations within 6 days. Tourniquet isolation of the limb can achieve extremely high concentrations of thrombolytic drugs while reducing the potential for systemic fibrinolysis and allows lysis of previously inaccessible thrombus.

Adult↗

PubMed1992

Vascular applications of lasers.

There have been major advances in laser technology and in our understanding of the effects of laser energy on blood vessels. This, in turn, has led to the many clinical applications of lasers in patients with vascular disease. The clinical results of laser endarterectomy, laser angioplasty, laser-assisted balloon angioplasty, laser-assisted vascular anastomoses, and the future of lasers in cardiovascular disease are discussed.

Humans↗

PubMed1992

Thrombolytic therapy.

Thrombolytic therapy may be used as either sole treatment or an adjunct to surgery in both arterial and venous disease. The age of the clot, particularly with venous thrombosis, determines the probability of successful lysis, with recent clot being highly susceptible to lytic therapy. The technique of thrombolysis is also an important determinant of the outcome, with high doses delivered directly into the clot over short time periods associated with the highest success and the lowest complication rates. Because systemic therapy increases the risk of bleeding from a remote site, techniques to concentrate the lytic agent within the clot, such as intraoperative high-dose and isolated-limb therapy, may achieve a higher success with a lower complication rate. Newer agents, which are clot specific, will be available for lytic therapy and should result in even higher success rates while minimizing systemic complications.

Fibrinolytic Agents↗

PubMed1991

A comparison of absorbable suture and argon laser welding for lateral repair of arteries.

Conventional vascular anastomoses between autogenous vessels are performed with nonabsorbable sutures. Recently, use of absorbable sutures and laser-assisted vascular anastomoses has been advocated because of their improved healing characteristics. This study compared arterial repairs with the argon laser, absorbable suture, and nonabsorbable suture for technical characteristics including additional suture and overall success rates, burst strength, and cost. Absorbable and nonabsorbable suture closures were comparable with respect to technique, but laser-assisted vascular anastomosis was technically more demanding and required almost twice as much time for completion. The argon laser successfully closed only 58.6% of the arteriotomies, and 90% of the closures required additional sutures for complete hemostasis. All sutured arteriotomies were successfully completed by use of either absorbable or nonabsorbable suture. Burst strength was similar for all groups, but was uniformly greater than 300 mm Hg for sutured repairs, whereas two of five laser-assisted closures burst below 300 mm Hg. Finally, costs for purchasing ($35,000) and operating ($300/hr.) an argon laser make laser-assisted vascular anastomosis much more expensive than sutured repair. These data suggest argon laser-assisted vascular anastomoses are more technically demanding, less successful, and more expensive than conventional sutured anastomoses when evaluated in large caliber arteries in a canine model. Absorbable suture, however, is comparable to conventional nonabsorbable sutured arterial repairs in expense, handling characteristics, and success rates with the added advantage of eliminating permanent foreign body in the arterial wall when it is absorbed.

Absorption↗