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Biomedical subjects

J M Seeger

Publications and source records attributed to J M Seeger.

At least 55 records · Page 3Linked to original sources
PubMed1996

Visceral ischemia-reperfusion injury promotes tumor necrosis factor (TNF) and interleukin-1 (IL-1) dependent organ injury in the mouse.

Acute visceral ischemia and subsequent reperfusion injury, which accompanies the surgical repair of a thoracoabdominal aorta aneurysm, is associated with high rates of morbidity and mortality. The purpose of the present study was to determine whether endogenous tumor necrosis factor-alpha (TNF-alpha) and interleukin-1 (IL-1) production contributes to organ dysfunction in animals subjected to visceral ischemia secondary to 30 min of supraceliac aortic occlusion. C57BL6/j mice were treated with either a TNF binding protein (TNF-bp-10 mg/kg) or an anti-IL-1 receptor type 1 antibody (150 micrograms) 2 h prior to 30 min of supraceliac aortic occlusion. An additional group of mice received 30 min of infrarenal aortic occlusion to determine the contribution of lower torso ischemia-reperfusion injury to the changes seen following supraceliac aortic occlusion. Visceral organ ischemia for 30 min produced by supraceliac aortic occlusion followed by 2 h of reperfusion produced measurable TNF-alpha in 38% of untreated mice, but TNF-alpha was undetectable in both sham-operated mice and following infrarenal aortic occlusion. After 2 h of reperfusion, lung myeloperoxidase levels were significantly elevated in the mice experiencing visceral ischemia-reperfusion compared with either a sham operation or infrarenal ischemia-reperfusion (11.6 +/- 1.3 U/g vs. 3.4 +/- .2 U/g and 3.7 +/- 1.0 U/g, respectively, p < .05). Pretreatment with TNF-bp and anti-IL-1 antibody decreased lung neutrophil recruitment (7.2 +/- 1.2 U/g and 4.6 +/- 1.1 U/g) and capillary membrane permeability changes in mice following visceral ischemia-reperfusion. The present study demonstrates that brief (30 min) clinically relevant visceral ischemia produces TNF-alpha and IL-1 dependent lung injury.

Animals↗
PubMed1995

The relationship between carotid plaque composition, plaque morphology, and neurologic symptoms.

Variations in plaque composition could make carotid artery plaques prone to ulceration, subintimal hemorrhage, plaque progression, or embolization and, thus, increase the risk of ipsilateral ischemic neurologic events. Seventy-eight carotid endarterectomy specimens from 74 patients (38 symptomatic and 36 asymptomatic) were analyzed. Prior to analysis, 43 of the 78 plaques were divided into sections based on disease severity and examined by light microscopy for surface ulceration and subintimal hemorrhage. Extracted lipid, cholesterol, collagen, and calcium content were determined in all 78 plaques and compared to clinical presentation and/or morphologic observations. Plaques removed from symptomatic patients contained more extracted lipid and cholesterol than those from asymptomatic patients. In addition, compared to the remainder of the plaque, the most stenotic portion of the plaque contained more cholesterol, more calcium, and less collagen. Finally, irrespective of clinical presentation, plaque sections found to have surface ulceration and subintimal hemorrhage contained more cholesterol and less collagen than plaques without these changes. Lipid-laden plaques with low levels of collagen are associated with plaque ulceration, subintimal hemorrhage, and ischemic neurologic symptoms. This suggests that plaque composition may be an important factor in the pathophysiology of carotid atherosclerosis.

Aged↗
PubMed1995

Selection of patients for renal artery repair using captopril testing.

BACKGROUND: Prediction of improvement following surgical or radiologic intervention in patients thought to have renovascular hypertension (RVH) is often unreliable. Use of the angiotensin-converting enzyme inhibitor captopril in conjunction with measurement of peripheral renin levels or radioisotope renograms is thought to detect patients with functionally significant renal artery stenosis. However, it is unclear whether these tests can identify patients whose hypertension will significantly improve after renal artery repair. PATIENTS AND METHODS: The records of 52 consecutive hypertensive patients undergoing captopril studies followed by renal artery repair were reviewed. All patients had either renal artery stenosis > 75% or renal artery occlusion. Preprocedure evaluation included a captopril challenge test (measurement of peripheral renin levels after captopril ingestion) (n = 12) or a captopril renogram (determination of renal blood flow and glomerular filtration rate before and after captopril administration) (n = 40). Either renal artery bypass/nephrectomy (n = 41) or balloon angioplasty (n = 11) was done in all patients (18 bilateral/34 unilateral). No periprocedural deaths occurred. All surgically placed bypass grafts were shown to be patent by contrast or carbon dioxide arteriography before hospital discharge. RESULTS: Preprocedure captopril tests were positive (suggestive of RVH) in 39 patients (75%) and negative in 13 (25%). All patients with positive captopril tests had improvement in their RVH after intervention (17 cured, 22 improved) while 8 of 13 patients with negative captopril tests had no improvement in blood pressure control. Four of five false-negative tests were associated with a unilateral total renal artery occlusion, making detection of a postcaptopril effect impossible. If these 4 patients are excluded from analysis, preprocedure captopril testing was 98% accurate in predicting postprocedure outcome. CONCLUSIONS: Preprocedure captopril testing permits extremely accurate selection of patients with renal artery stenosis who will benefit from renal artery repair.

Adult↗
PubMed1995

Operative mortality rates after elective infrarenal aortic reconstructions.

PURPOSE: This study was designed to test the hypothesis that cardiac complications (myocardial infarction, congestive heart failure, fatal arrhythmias) are no longer the leading cause of death after elective aortic reconstructions. METHODS: The medical records of all elective infrarenal aortic reconstructions performed between January 1982 and June 1994 were retrospectively reviewed. All perioperative deaths were analyzed to determine the cause of death and were compared with a subset of 266 survivors to identify any associated preoperative or intraoperative factors. RESULTS: Seven hundred twenty-two aortic reconstructions were performed for aneurysmal or occlusive disease, and there were 44 deaths (overall mortality rate of 6.1%). The mortality rate after aortic reconstruction alone was 4.9% and increased with the addition of renal (8.9%, p = 0.16) or lower extremity vascular procedures (15.8%, p = 0.01). Multisystem organ failure (MSOF) was the cause of death in 56.8%, of the patients (3.5% overall mortality rate) followed by cardiac events in 25% (1.5% overall mortality rate). Visceral organ dysfunction was the most common cause of MSOF leading to death in 14 patients (56.0%), and postoperative pneumonia was responsible for the fatal MSOF in nine patients (36.0%). Patient age, history of myocardial infarction/congestive heart failure, ejection fraction less than 50%, duration of operative time, and performance of additional procedures were associated with increased operative mortality rates by multivariate analysis. CONCLUSIONS: MSOF, predominantly from visceral organ dysfunction, was the leading cause of death after elective infrarenal aortic reconstruction. The risk of MSOF and operative death increases with the complexity of the procedure and the number of comorbid conditions.

Aged↗
PubMed1995

Hydrophilic surface modification of metallic endoluminal stents.

PURPOSE: Stainless steel endovascular stents are inherently thrombogenic so that thrombus accumulates on these devices, leading to acute vessel occlusion. A potential solution to this problem is stent surface modification with hydrophilic polymers, which might limit platelet adhesion and reactivity. METHODS: N-vinylpyrrolidone (NVP) and potassium sulfopropyl acrylate (KSPA) hydrophilic monomers were gamma graft polymerized onto 1 cm2 stainless steel slabs and 4 mm Palmaz stainless steel stents. Surface characteristics of modified and plain stainless steel stents were then investigated with contact angle and x-ray photoelectron spectroscopy measurements, and in vitro and in vivo platelet reactivity was assessed as 111Indium platelet accumulation expressed as counts/min/cm2. RESULTS: Surface modification of stainless steel slabs and stents with both NVP and KSPA hydrophilic polymers significantly reduced in vitro platelet adhesion (plain = 2249 +/- 723 counts/min/cm2, NVP = 428 +/- 156 counts/min/cm2, KSPA = 958 +/- 223 counts/min/cm2) and in vivo platelet accumulation after 1 hour of blood flow exposure (plain = 1407 +/- 796 counts/min/cm2, NVP = 426 +/- 175 counts/min/cm2, KSPA = 399 +/- 124 counts/min/cm2. In addition, platelet accumulation on modified stents indexed to plain stents was lowest in KSPA-modified stents (NVP = 79.3% +/- 31.7% of plain, KSPA = 51.2% +/- 36.2% of plain). Surface analysis confirmed surface grafting with both monomers, and SEM documented smoothing of the irregular surfaces of the stainless steel stents after grafting. CONCLUSION: Hydrophilic polymer surface modification of stainless steel stents decreases initial stent surface platelet accumulation, which may decrease the risk of vessel thrombosis associated with the use of these devices.

Blood Vessels↗
PubMed1995

Limb-threatening ischemia due to multilevel arterial occlusive disease. Simultaneous or staged inflow/outflow revascularization.

SUMMARY BACKGROUND DATA: Limb-threatening ischemia due to severe multilevel arterial occlusive disease may require both inflow and outflow bypass to achieve limb salvage. Simultaneous inflow/outflow bypass has been advocated because the cumulative risks of separate staged inflow/outflow procedures can be avoided. However, the magnitude of complete revascularization is substantial; thus, the morbidity and mortality of simultaneous inflow/outflow bypass may be excessive. METHODS: The medical records of 450 patients undergoing lower extremity arterial reconstruction between 1988 and 1994 were retrospectively reviewed, allowing identification of 54 patients who had undergone simultaneous aortoiliac and infrainguinal bypasses. This group consisted of 38 men and 26 women (mean age: 64.7 years), with significant cardiac disease in 24, smoking history in 53, and diabetes mellitus in 15. Indications for surgery were limb-threatening ischemia in 48 (89%) and severe short-distance claudication in 6 (11%). Inflow disease was corrected by direct aortoiliac reconstruction in 28, whereas other extra-anatomic bypasses were constructed in 26. Outflow revascularization required infrainguinal bypass to the infragenicular arteries in 46 (below-knee popliteal: 21; tibial: 25), a concomitant profundaplasty in 26, and a composite bypass conduit in 14. RESULTS: Limb salvage was 97% at 30 days whereas morbidity/mortality were 61% and 19%, respectively. However, the majority of complications and deaths occurred in patients undergoing aortic inflow plus complex outflow procedures (profundaplasty and/or composite bypass conduits), in which the morbidity/mortality rates were 84.2% and 47.4%, respectively, compared with rates of 45.7% and 2.9% (p < 0.01) after all other inflow/outflow procedures. The increased difficulty of these complex procedures is reflected in the significantly greater blood loss and operative times (1853 mL and 10.0 hours) compared with similar values (1125 mL and 7.7 hours)(p < 0.01) for all other inflow/outflow procedures. CONCLUSION: Simultaneous inflow/outflow bypasses are effective and safe in patients with severe, multilevel arterial occlusive disease, except when a complex outflow procedure is needed in conjunction with direct aortoiliac reconstruction. In the latter setting, a staged procedure is recommended because it may be associated with less morbidity and mortality.

Adult↗
PubMed1994

Rotational atherectomy for treatment of occluded prosthetic grafts.

Potentially, percutaneous rotational atherectomy (RA) can be used to open occluded prosthetic arterial bypass grafts with less morbidity than surgical catheter thrombectomy. However, RA could damage prosthetic grafts or produce significant distal emboli. To investigate this, acutely thrombosed and chronically occluded prosthetic grafts, harvested from dogs, were placed in an ex vivo perfusion system and recanalization was attempted using the TRAC-Wright rotational atherectomy system. Urokinase (UK) was delivered through the RA catheter in one-half of the procedures. Graft surface thrombogenicity and graft mechanical integrity after successful recanalization were determined and debris released during recanalization was collected. Results were compared to those from grafts opened by catheter thrombectomy. One hundred percent (22/22) of acute prosthetic graft occlusions and 39% (16/41) of chronic prosthetic graft occlusions were opened using RA, similar to results achieved using catheter thrombectomy. In addition, surface thrombogenicity after recanalization of acute graft occlusion with RA was lower than that after catheter thrombectomy (P < 0.05) and infusion of UK improved RA success in chronically occluded grafts (52% vs 25%). Debris generated during RA averaged 15-18 micrograms, equivalent to debris generated during catheter thrombectomy, and graft mechanical integrity was unaffected by recanalization using RA. Thus, rotational atherectomy is a minimally invasive means of safe and effective prosthetic graft recanalization that produces a less thrombogenic graft than thrombectomy.

Animals↗
PubMed1994

Glutamine preserves gut glutathione levels during intestinal ischemia/reperfusion.

Intestinal ischemia/reperfusion (I/R) causes formation of reactive oxygen intermediates (ROI) which lead to mucosal cell injury. Glutathione (GSH), an ROI scavenger, protects tissues from ROI-mediated cell injury. Since GSH biosynthesis is partially dependent on glutamine (Gln) levels, we tested the hypothesis that intravenous Gln infusion will assist in maintaining mucosal cell GSH levels and decrease membrane lipid peroxidation during intestinal I/R. The external jugular vein of male Sprague-Dawley rats was cannulated and infused with normal saline (NS) at 2 cc/hr. After 3 days, matched pairs of rats received either NS alone or NS+ 3% Gln for an additional 24 hr. Next, mucosal GSH levels were measured after a sham I/R in 6 rats and after either 30 or 60 min of ischemia/60 min of reperfusion in a group of 8 and 12 rats, respectively. Finally, conjugated diene (CD), a byproduct of membrane lipid peroxidation, was measured following 60 min of ischemia/60 min of reperfusion in a separate group of 12 rats. Control rats had the highest GSH levels and there was no difference between NS vs NS + 3% Gln rats (2.50 +/- 0.48 vs 2.50 +/- 0.43, P = NS). With 30 and 60 min of ischemia/60 min of reperfusion, GSH levels were significantly lower in NS-infused rats compared to those in NS + 3% Gln-infused rats (30 min: 1.54 +/- 0.14 vs 1.80 +/- 0.16, P < 0.05; 60 min: 1.27 +/- 0.15 vs 1.52 +/- 0.20, P < 0.04). In addition, CD levels were lower in NS + 3% Gln-infused rats compared to those in NS alone-infused rats (5.58 +/- 0.87 vs 7.94 +/- 0.55, P < 0.04). In conclusion, Gln supplementation partially maintains gut GSH levels during bowel I/R, which in turn lessens I/R-induced cell membrane lipid peroxidation.

Animals↗
PubMed1994

Impact of angioscopy on infrainguinal graft patency.

To investigate the impact of angioscopy on infrainguinal graft patency, 50 consecutive cases with angioscopy as an adjuvant to infrainguinal arterial bypass performed during a 12-month period were reviewed (group I). For comparison, 42 similar cases of infrainguinal arterial reconstruction performed during the 12 months prior to introduction of routine intraoperative angioscopy were also reviewed (group II). Patients were followed up for 12 months and graft patency was determined at 1, 3, 6, and 12 months. An abnormality was identified in 13 (26%) group I patients (10, angioscopy alone; 1, arteriography alone; 2, both). Defects were anastomotic abnormalities (n = 7), vein sclerosis (n = 3), retained valve cusp (n = 2), and proximal artery stenosis (n = 1). A similar percentage, but different types of defects, were seen in group II; 11 patients (26%) had an abnormality (anastomotic abnormality [n = 3], vein sclerosis [n = 4], retained valve cusp [n = 1], and arterial outflow stenoses [n = 3]). All significant defects were surgically explored and corrected. Graft patency rates in group I and II at 1, 3, 6, and 12 months were 100% and 85% (P < 0.005), 94% and 80% (P < 0.05), 87% and 74% (P = non-significant [NS]), and 86.1% and 73.7% (P = NS), respectively. Intraoperative angioscopy detects anastomotic and vein graft defects not always seen on arteriography; the repair of these defects significantly improves early infrainguinal bypass graft patency rates.

Adult↗
PubMed1994

Does routine stress-thallium cardiac scanning reduce postoperative cardiac complications?

OBJECTIVE: Prophylactic cardiac revascularization in patients with ischemic myocardium could reduce postoperative cardiac complications after aortic reconstruction. However, the effectiveness of this approach has not been documented. SUMMARY BACKGROUND DATA: Stress-thallium scanning can identify patients with ischemic myocardium. Morbidity and mortality after aortic reconstruction appears to be largely caused by co-existent coronary artery disease, and patients who have had recent cardiac revascularization have few postoperative cardiac complications. METHODS: Preoperative stress-thallium scanning was evaluated prospectively in 146 patients undergoing aortic reconstruction. Patients with positive studies underwent coronary arteriography and cardiac revascularization, when appropriate. Postoperative cardiac complications and long-term survival in these patients were compared with results from 172 similar patients undergoing aortic reconstruction without stress-thallium scanning. Results also were analyzed to determine predictors of postoperative cardiac events. RESULTS: Forty-one per cent of patients undergoing stress-thallium testing underwent coronary arteriography, and 11.6% had cardiac revascularization. In contrast, 14.7% of patients treated without stress-thallium testing had coronary arteriography, and 4.1% had revascularization (p < 0.01). Despite this, cardiac mortality, serious cardiac complications, and long-term cardiac mortality were similar in both groups. Only advanced age and intraoperative complications (but not a positive stress-thallium test) predicted postoperative cardiac events. CONCLUSIONS: Preoperative stress-thallium testing confirmed a high incidence of significant coronary artery disease in patients undergoing aortic reconstruction, but prophylactic cardiac intervention does not reduce operative or long-term mortality. Thus, the risk and expense of routine stress-thallium testing and subsequent cardiac revascularization cannot be justified.

Aged↗
PubMed1993

Detection of celiac axis and superior mesenteric artery occlusive disease with use of abdominal duplex scanning.

PURPOSE: Detection of mesenteric arterial insufficiency is clinically difficult, and diagnosis frequently requires arteriography. Advances in duplex scanning make this an ideal technique to noninvasively screen patients for chronic mesenteric arterial occlusive disease. However, the accuracy of mesenteric duplex scanning compared with arteriography remains unclear. This study will clearly define the accuracy of abdominal duplex scanning for detection of mesenteric arterial insufficiency. METHODS: The mesenteric duplex scans of 38 patients obtained over a 4-year period were reviewed and compared with lateral aortograms to clarify this issue. Optimal peak systolic frequency (PSF) for predicting less than 50% or 50% or greater stenoses of the superior mesenteric artery (SMA) and celiac axis (CA) were determined from receiver-operating characteristic curves. RESULTS: In the SMA a PSF of 4.5 kHz was 96% sensitive (24/25), 92% specific (12/13), and 95% accurate (36/38) at predicting stenoses less than 50% or 50% or greater. For arteries with stenoses 50% to 99%, regression analysis demonstrated excellent linear correlation between percent stenosis and PSF (r = 0.89). In the CA a PSF of 4.0 kHz had a sensitivity of 100% (30/30), a specificity of 88% (7/8), and an accuracy of 97% (37/38). Again, for arteries with stenoses 50% to 99%, an excellent linear correlation existed between PSF and percent stenosis (r = 0.86). All total arterial occlusions (14) were correctly identified. In all, mesenteric arterial duplex scanning was 96% accurate for predicting SMA and CA stenoses/occlusions. CONCLUSIONS: Abdominal duplex scanning is a noninvasive technique that accurately detects total occlusions and objectively quantitates SMA and CA arterial stenoses.

Aorta, Abdominal↗
PubMed1993

Follow-up evaluation after renal artery bypass surgery with use of carbon dioxide arteriography and color-flow duplex scanning.

PURPOSE: Postoperative evaluation of renal artery bypass grafts historically has been obtained by contrast renal arteriography before discharge from the hospital. Recent reports have advocated replacing arteriography with abdominal duplex scanning for evaluating and monitoring the integrity of renal artery bypasses. We propose a combination of these two techniques, which provides minimal risk to the patient and renal parenchymal function. PURPOSE: Between July 1, 1990, and Dec. 31, 1991, 17 patients (8 men, 9 women) underwent 24 renal artery bypasses for poorly controlled hypertension or deteriorating renal function. In the immediate postoperative period each patient underwent carbon dioxide (CO2) renal arteriography to detect any technical defects and to define bypass graft anatomy. Subsequently, color-flow duplex scanning of the renal artery bypass grafts were done at 3-month intervals with the postoperative CO2 arteriogram for baseline comparison. CO2 arteriography clearly defined proximal/distal anastomotic anatomy, bypass conduit integrity, and bypass conduit runoff. RESULTS: Procedural morbidity was zero because no hematomas developed and serum creatinine remained stable. Duplex scanning for a mean follow-up of 8.3 months revealed antegrade flow in 23 bypasses with peak systolic velocity of 60 to 100 cm/sec. One bypass graft had a peak systolic velocity greater than 150 cm/sec suggestive of a proximal anastomotic stenosis; however, the patient died before a repeat, verifying CO2 arteriogram could be obtained. Recurrent hypertension developed in one patient with velocities less than 100/cm/sec, and repeat CO2 arteriography revealed no evidence of graft or anastomotic stenosis. CONCLUSION: CO2 arteriography and duplex scanning provide an accurate means of initially evaluating and subsequently monitoring renal artery bypass grafts, with minimal risk of renal or patient morbidity.

Adult↗
PubMed1993

Multiple organ dysfunction after mesenteric artery revascularization.

PURPOSE: Mesenteric arterial reconstruction in patients with acute or chronic intestinal ischemia is associated with significant morbidity and mortality rates. Reperfusion of ischemic bowel in animals leads to release of multiple factors that cause organ dysfunction. Similar phenomena potentially occur in human beings after repair of symptomatic chronic mesenteric arterial disease. The purpose of this study was to define the incidence of multiple organ dysfunction seen after reperfusion of the chronically ischemic bowel. METHOD: Between January 1990 and January 1993, 18 patients underwent surgical revascularization for symptomatic chronic mesenteric arterial occlusive disease. Four patients required emergency surgery, whereas 14 procedures were done electively. Hepatic, renal, pulmonary, and coagulation function were evaluated in all patients. Bypass graft patency was confirmed by duplex scanning or repeat operation in all patients with deteriorating conditions. RESULTS: Immediately after surgery hepatic function deteriorated. The serum transaminases increased 90- to 100-fold whereas lactate dehydrogenase increased 25-fold. Simultaneously, platelet counts dropped below 40,000 mm3 in 11 patients. On postoperative day 2, 16 patients had acute pulmonary insufficiency demonstrated by an increase in the pulmonary shunt fraction to a mean of 32% +/- 3% (range 21% to 60%). Ten patients required reintubation, and lung failure lasted an average of 8.4 days (range 1 to 35 days). Hepatic and coagulation function changes were usually transient, returning to baseline within 7 to 10 days. Four of the patients who had multiple organ dysfunction died (two after elective surgery), and one patient died of myocardial infarction after emergency surgery. CONCLUSION: Revascularization of chronically ischemic bowel leads to significant multiple organ dysfunction, potentially as a result of intestinal ischemia and reperfusion injury.

Adult↗
PubMed1993

Carbon dioxide gas as an arterial contrast agent.

OBJECTIVE: To investigate the clinical utility of CO2 gas as an arterial contrast agent, the experience with CO2 arteriography at the University of Florida was reviewed. SUMMARY BACKGROUND DATA: Preliminary studies have demonstrated the feasibility of CO2 arteriography and shown that arterial injection of CO2 gas appears non-toxic (which could limit the risks of contrast induced renal injury and allergic reaction). However, numerous technical problems make CO2 arteriography a demanding technique and recent studies have suggested that distal lower extremity vessels are difficult to image using CO2 arteriography, especially when significant arterial occlusive disease is present. METHODS: One hundred twenty-eight CO2 arteriograms done in 115 patients were reviewed. CO2 arteriograms were graded as excellent, good, poor, or inadequate by two blinded observers and results of CO2 studies compared to results of standard contrast studies (done in 98 patients for image comparison). In addition, a therapeutic plan based on the CO2 arteriograms was compared with the therapy each patient received. RESULTS: One hundred-seventeen (91%) of the CO2 arteriograms were of good or excellent quality and agreement between CO2 studies and standard contrast studies was seen in 93 of 98 cases (95%). Accurate therapeutic plans based on CO2 studies were possible in 92% of cases with inadequate visualization of infrapopliteal arteries being the major limitation (7 cases). No allergic reactions occurred and only one patient potentially had contrast-induced nephrotoxicity. CONCLUSIONS: CO2 arteriography provides accurate, clinically useful arterial imaging with minimal risk. Thus, this new technology significantly increases the utility of arteriography in patients with peripheral vascular disease.

Adult↗
PubMed1993

Limitations and pitfalls of laser angioplasty.

Overall, the initial and long-term results of LABA have been disappointing. Poor initial recanalization rates and high restenosis and hemodynamic failure rates have caused investigators to reevaluate the indications for LABA. This reevaluation has resulted in an appropriate limitation of the indications for LABA. At present, LABA is probably indicated only for the treatment of patients with symptomatic, isolated arterial occlusions in whom conventional balloon angioplasty cannot be done because mechanical recanalization using a guidewire is not possible. Other uses of LABA in patients with peripheral vascular disease are discouraged and should be considered experimental. New innovations in technology, including improved arterial imaging techniques and better laser delivery systems, are required before LABA can become a standard therapy for the treatment of patients with peripheral vascular disease. A search for an "ideal" laser wavelength for arterial recanalization is futile until these developments occur. Once these innovations are in use, laser angioplasty may be an important technique in the treatment of peripheral vascular disease. This potentially valuable tool for the vascular surgeon should not be abandoned. Rather, it should be laid aside until it is better developed.

Angioplasty, Balloon, Laser-Assisted↗
PubMed1992

In vitro laser recanalization of chronically occluded prosthetic grafts.

Polytetrafluoroethylene (PTFE) and Dacron grafts were implanted in canine femoral and carotid arteries using PTFE and Prolene suture, respectively. Arteries containing occluded grafts were explanted and laser recanalization was attempted in vitro. Laser recanalization was successful in 78% of PTFE grafts compared to 30% of Dacron grafts. Recanalization was complete (residual stenosis less than 5%) in opened PTFE grafts, whereas residual stenosis averaged 60% in recanalized Dacron grafts. PTFE graft/PTFE suture anastomotic tensile strength was unchanged after recanalization, while Dacron graft/Prolene suture anastomotic tensile strength decreased significantly. In addition, anastomotic bursting pressure was significantly higher for lased PTFE grafts with PTFE sutures (300 mg Hg) compared to lased Dacron grafts with Prolene sutures (70 mm Hg). Chronically occluded PTFE grafts with PTFE suture can be safely and effectively opened by laser recanalization. In contrast, attempted laser recanalization of Dacron grafts sutured with Prolene suture is seldom successful, significantly weakens the graft artery anastomosis, and should be avoided.

Anastomosis, Surgical↗
PubMed1992

Laser angioplasty.

Laser energy has the potential for selective ablation of atherosclerotic plaque through minimally invasive means. As currently practiced, laser angioplasty requires the adjunct of balloon angioplasty in most cases and has limited application compared with more conventional methods of revascularization. However, new advances in guidance systems, delivery devices, and laser sources may allow realization of the full benefit of this technology at some point in the future.

Angioplasty, Laser↗