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Biomedical subjects

L M Messina

Publications and source records attributed to L M Messina.

At least 19 recordsLinked to original sources
PubMed2005

Optimization of adenovirus-mediated endothelial nitric oxide synthase delivery in rat hindlimb ischemia.

Adenovirus-mediated overexpression of endothelial nitric oxide synthase (eNOS) induces collateral artery development and substantially increases blood flow after induction of experimental acute hindlimb ischemia. However, the optimal technique of gene delivery for this or any other form of gene therapy in limb ischemia is still unknown. The purpose of this study was to determine the effect of the two most commonly used techniques, intra-arterial and intramuscular injection, on blood flow recovery, collateral artery development, and preservation of muscle mass. We compared intra-arterial injection under vascular isolation, intra-arterial injection under transient vascular occlusion, and intramuscular injection of phosphate buffered saline (PBS) or adenovirus encoding either the eNOS (AdeNOS) or LacZ (AdlacZ) gene after induction of acute hindlimb ischemia. Delivery of AdeNOS by both intra-arterial injection techniques increased eNOS activity (22.30 versus 10.56, P<0.01), blood flow (0.90+/-0.02 versus 0.69+/-0.07, P<0.001) and collateral artery development (17.56484 versus 13.74259, P<0.05) more than by intramuscular delivery. Intra-arterial injection under transient vascular occlusion led to better preservation of muscle mass, muscle architecture, and clinical ischemic index, but led to greater transgene expression in distant organs and contralateral limb muscles. Intra-arterial injection of AdeNOS under transient vascular occlusion is the optimal technique to reverse severe hindlimb ischemia in the rat. This is the first systematic comparison of different delivery techniques used in gene therapy of experimental hindlimb ischemia.

Adenoviridae↗
PubMed2004

The incidence of iliac aneurysms in patients with abdominal aortic aneurysms: comparison of four centers in Europe and the USA.

BACKGROUND: The purpose of this study was to compare the anatomy of the aortoiliac vessels in patients scheduled for infrarenal abdominal aortic aneurysm (AAA) repair in four different countries. MATERIAL AND METHODS: Consecutives series of 100 preoperative CT-scans were evaluated at each center. Diameters of the suprarenal aorta, maximal diameter of the aneurysm, right and left common and external iliac artery as well as the hypogastric arteries were recorded and compared between each center. RESULTS: Configuration of the AAA above bifurcation was similar at each center. The dimensions of the aortic bifurcation and the common iliac arteries were different among the centers. Common iliac arteries with diameters over 25 mm were significantly more common at center 1 (p < 0.001, p = 0.002 and p < 0.001). Among centers 2, 3 and 4 there was no significant difference in common iliac diameters. CONCLUSIONS: Configuration of the iliac arteries in AAA was significantly different for Swiss patients compared to American, Austrian and German patients. Reasons for these differences are unclear, epidemiological or genetic factors may be responsible.

Adult↗
PubMed2001

C-reactive protein levels and viable Chlamydia pneumoniae in carotid artery atherosclerosis.

BACKGROUND AND PURPOSE: An elevated serum level of C-reactive protein, an inflammatory marker, is an independent predictor of stroke and coronary artery disease. To determine whether chronic infection with Chlamydia pneumoniae, which has been identified in atherosclerotic plaques, is responsible for systemic inflammation, we studied the association between serum C-reactive protein levels and infection of carotid artery atherosclerotic plaque with viable C pneumoniae. METHODS: Serum C-reactive protein levels were obtained before endarterectomy for carotid artery stenosis. Plaques were tested for C pneumoniae mRNA, an indicator of viability, and DNA by polymerase chain reaction of DNA and cDNA, respectively. RESULTS: Forty-eight samples were studied, of which 18 (38%; 95% CI, 23 to 50) were infected with viable C pneumoniae as evidenced by isolated chlamydial mRNA. All 18 of these samples, plus 1 additional sample, were positive for chlamydial DNA. Serum C-reactive protein levels were higher in those with viable C pneumoniae compared with those without infection (median, 8 mg/L versus undetectable; P=0.045 by Wilcoxon rank-sum test). In multivariable models, the only independent predictor of the presence of viable C pneumoniae was a detectable C-reactive protein level (odds ratio, 4.2; 95% CI, 1.1 to 17; P=0.04). CONCLUSIONS: Viable C pneumoniae are present in a substantial portion of carotid artery atherosclerotic plaques and are associated with increased serum C-reactive protein levels. These findings may explain the link between elevated C-reactive protein levels and the risk of cardiovascular disease and stroke but should be reproduced in a larger cohort.

Aged↗
PubMed2001

Exercise-induced hyperemia unmasks regional blood flow deficit in experimental hindlimb ischemia.

UNLABELLED: Many experimental models of hindlimb ischemia are characterized by spontaneous and rapid normalization of resting muscle blood flow (BF) rates which complicates the long-term evaluation of angiogenic therapies to reverse limb ischemia. We tested the hypothesis that peroneal nerve stimulation in an ischemic hindlimb would increase the oxygen (O(2)) demand and BF rate, thereby unmasking a severe blood flow deficit that is not apparent at rest. METHODS: Ischemia was induced in adult rats by ligation of the left common iliac, femoral arteries, and their branches. Peroneal nerves were stimulated to allow measurement of exercise-induced regional BF rates with fluorescent microspheres. Hemodynamics were monitored. Fluorescent microspheres were injected before and after 5 min of nerve stimulation 3, 10, and 24 days postischemia. The tibialis anterior (TA) and gastrocnemius (GC) muscles and skin were harvested and weighed, and fluorescence was measured. BF rate was calculated as milliters per minute per gram of tissue and compared to normal muscle and skin of unoperated control rats. In order to determine the accuracy of BF rate measurements in ischemic muscle when <400 microspheres was delivered per specimen, 3 rats were studied by simultaneous injection of 4 x 10(5) blue and 1 x 10(5) yellow-green fluorescent microspheres. The correlation coefficient between the number of different colored microspheres delivered was measured. RESULTS: The ischemia caused atrophy of the TA and GC muscles. The mean muscle mass of the ischemic TA and GC as a percentage of total body weight decreased over time vs control [TA 0.13 +/- 0.05% vs 0.25 +/- 0.03%, P < 0.05; GC 0.51 +/- 0.27% vs 0.70 +/- 0.07%, P = 0.07 at 24 days (24D)]. Despite clinical evidence of severe hindlimb ischemia in experimental groups, i.e., pressure sores, muscle atrophy, and weakness, resting BF rates were not significantly different from those of control. The BF rate of the TA was of 0.11 ml/min/g after 3D of ischemia, 0.14 ml/min/g after 10D, and 0.13 ml/min/g after 24D. The mean BF rate in normal muscle of unoperated controls was 0.16 ml/min/g (P > 0.05). However, the exercise-induced hyperemia in the skeletal muscle was significantly blunted in all of the ischemic groups. The unoperated control TA had a greater than 10-fold increase in BF to 1.95 ml/min/g in response to exercise while the ischemic TA had no increase in BF at 3D, 2-fold increase at 10D, and a 5-fold increase at 24D. Parallel findings were noted in the GC muscles. There was no significant difference in the BF rate in the skin. The accuracy of this microsphere technique in measuring very low BF rates found in ischemic muscle was supported by the significant correlation coefficient (r = 0.99) comparing two quantities of microspheres injected simultaneously. CONCLUSION: Despite clinical signs of severe hindlimb ischemia, resting BF rates in the ischemic groups were not significantly decreased. Peroneal nerve stimulation resulted in up to 10-fold increase in BF rate and unmasked a severe deficit in vascular reserve in the ischemic groups. Resting BF rate is not always an accurate reflection of the flow deficit in models of critical limb ischemia, and this model of exercise-induced hindlimb hyperemia may allow better long-term evaluation of angiogenic therapies designed to reverse critical limb ischemia.

Animals↗
PubMed2001

Endoleak after endovascular repair of abdominal aortic aneurysm.

PURPOSE: We sought to assess the role of endovascular techniques in the management of perigraft flow (endoleak) after endovascular repair of an abdominal aortic aneurysm. METHOD: We performed endovascular repair of abdominal aortic aneurysm in 114 patients, using a variety of Gianturco Z-stent-based prostheses. Results were evaluated with contrast-enhanced computed tomography (CT) at 3 days, 3 months, 6 months, 12 months, and every year after the operation. An endoleak that occurred 3 days after operation led to repeat CT scanning at 2 weeks, followed by angiography and attempted endovascular treatment. RESULTS: Endoleak was seen on the first postoperative CT scan in 21 (18%) patients and was still present at 2 weeks in 14 (12%). On the basis of angiographic localization of the inflow, the endoleak was pure type I in 3 cases, pure type II in 9, and mixed-pattern in 2. Of the 5 type I endoleaks, 3 were proximal and 2 were distal. All five resolved after endovascular implantation of additional stent-grafts, stents, and embolization coils. Although inferior mesenteric artery embolization was successful in 6 of 7 cases and lumbar embolization was successful in 4 of 7, only 1 of 11 primary type II endoleaks was shown to be resolved on CT scanning. There were no type III or type IV endoleaks (through the stent-graft). Endoleak was associated with aneurysm dilation two cases. In both cases, the aneurysm diameter stabilized after coil embolization of the inferior mesenteric artery. There were two secondary (delayed) endoleaks; one type I and one type II. The secondary type I endoleak and the associated aneurysm rupture were treated by use of an additional stent-graft. The secondary type II endoleak was not treated. CONCLUSIONS: Type I endoleaks represent a persistent risk of aneurysm rupture and should be treated promptly by endovascular means. Type II leaks are less dangerous and more difficult to treat, but coil embolization of feeding arteries may be warranted when leakage is associated with aneurysm enlargement.

Aortic Aneurysm, Abdominal↗
PubMed2001

Administration of adenoviral vectors induces gangrene in acutely ischemic rat hindlimbs: role of capsid protein-induced inflammation.

PURPOSE: The initial purpose of this study was to determine the effects of intravascular adenoviral vector-mediated gene transfer of endothelial nitric oxide synthase (AdeNOS) on experimental hindlimb ischemia in the rat. Unexpectedly, administration of AdeNOS immediately after induction of acute limb ischemia led to limb gangrene. We subsequently sought to define the molecular mechanisms responsible for this unusual effect and to devise adenoviral gene transfer strategies to prevent the development of gangrene in acutely ischemic limbs. METHODS: Phosphate-buffered saline or adenoviral vectors containing the bovine endothelial nitric oxide synthase gene (AdeNOS) or no transgene (Ad-E1) were injected intra-arterially into the hindlimb of a rat under vascular isolation immediately after surgical induction of severe ischemia. Hematoxylin and eosin staining was performed on muscle sections to evaluate inflammation. A separate group of animals was injected with an adenovirus containing a nontranscribable genome, treated with cyclosporine, or received delayed administration of the adenoviral vector. Gene expression after delayed adenoviral gene transfer was assessed with immunohistochemistry, Western blotting, and nitric oxide synthase (NOS) activity assay. RESULTS: Both AdeNOS and Ad-E1 caused gangrene of the entire hindlimb within 12 days in a dose-dependent manner, at a threshold concentration of 1 x 10(9) plaque-forming unit/mL. Adenoviral delivery was associated with more inflammation and edema compared with phosphate-buffered saline histologically. Inactivation of adenoviral DNA transcription did not affect induction of gangrene. However, gangrene was prevented by concurrent immunosuppression with cyclosporine or delayed administration of the vector. Delayed administration allowed adenoviral gene expression as determined by immunohistochemistry, NOS protein levels, and an assay of NOS enzyme activity. CONCLUSION: Intra-arterial administration of adenoviral vectors, under vascular isolation, immediately after induction of acute ischemia causes inflammation and subsequent limb gangrene. The inflammatory response is unrelated to the expression of the recombinant transgene or the adenoviral genome and is likely due to the adenoviral capsid proteins. However, administration of cyclosporine or delayed injection of the adenoviral vector is a method that can be used for adenoviral mediated gene transfer in limb ischemia.

Acute Disease↗
PubMed2001

An endovascular system for thoracoabdominal aortic aneurysm repair.

PURPOSE: To describe a stent-graft system for endovascular repair of thoracoabdominal aortic aneurysm (TAAA) that preserves side branch perfusion. TECHNIQUE: The modular endograft system includes 3 components. The primary stent-graft is custom-made from conventional graft fabric and Gianturco Z-stents. Covered nitinol Smart Stents are used for the visceral and renal extensions, and the distal extension is made from a modified Zenith system. With the supine patient under general anesthesia, the components are delivered sequentially through surgically exposed femoral and right brachial arteries in an operation that requires prolonged periods of magnified high-resolution imaging. This system was first used in a 76-year-old man with a contained rupture of a supraceliac ulcer and a large abdominal aortic aneurysm ending proximally at the celiac artery. The endograft was implanted successfully, but the patient developed paraplegia on day 2; imaging documented an excluded aneurysm and excellent flow through the endograft and all prosthetic branches. DISCUSSION: Endovascular repair of TAAA appears to be feasible. If there are no serious, specific, unavoidable complications, the potential advantages are enormous.

Aorta↗
PubMed2000

Endovascular aneurysm repair in high-risk patients.

PURPOSE: The purpose of this study was to evaluate the role of endovascular aneurysm repair in high-risk patients. METHODS: The elective endovascular repair of infrarenal aortic aneurysm was performed in 116 high-risk patients with either custom-made or commercial stent grafts. The routine follow-up examination included contrast-enhanced computed tomography (CT) before discharge, at 3, 6, and 12 months, and annually thereafter. Patients with endoleak on the initial CT underwent re-evaluation at 2 weeks. Those patients with positive CT results at 2 weeks underwent endovascular treatment. RESULTS: Endovascular repair was considered feasible in 67% of the patients. The mean age was 75 years, and the mean aneurysm diameter was 6.3 cm. The American Society of Anesthesiologists grade was II in 3.4%, III in 65.5%, IV in 30.1%, and V in 0.9%. There were no conversions to open repair. Custom-made aortomonoiliac stent grafts were implanted in 77.6% of the cases, custom-made aortoaotic stent grafts in 11.2%, and commercial bifurcated stent grafts in 11.2%. The 30-day rates of mortality, major morbidity, and minor morbidity were 3.4%, 20.7%, and 12%, respectively, in the first 58 patients and 0%, 3.4%, and 3.4%, respectively, in the last 58. The late complications included five cases of stent graft kinking, two cases of femorofemoral graft occlusion, and three cases of proximal stent migration, one of which led to aneurysm rupture. At 2 weeks after repair, endoleak was present in 10.3% of the cases. All the type I (direct perigraft) endoleaks underwent successful endovascular treatment, whereas only one type II (collateral) endoleak responded to treatment. The technical success rate at 2 weeks was 86.2%, and the clinical success rate was 96.6%. The continuing success rate was 87.9%. Seventeen patients died late, unrelated deaths. CONCLUSION: Endovascular aneurysm repair is safe and effective in patients at high risk, for whom it may be the preferred method of treatment.

Aged↗
PubMed2000

Endovascular repair of a presumed aortoenteric fistula: late failure due to recurrent infection.

PURPOSE: To describe a case of presumed aortoduodenal fistula that was treated by endovascular implantation of a stent-graft. METHODS AND RESULTS: A 76-year-old man was transferred from another hospital where he had been treated for upper gastrointestinal hemorrhage over a 2-month period. Ten years previously, he had undergone aortobifemoral bypass, the right limb of which recently thrombosed. At the time of transfer, computed tomographic scanning showed a large false aneurysm between the aorta and the duodenum. Endoscopy disclosed mucosal erosions in the fourth portion of the duodenum. Following implantation of 2 overlapping stent-grafts, the bleeding ceased and the false aneurysm disappeared. At no time did the patient have a fever. The patient initially did well, but 8 months after treatment, he presented with fever and chills. Recurrent infection had caused erosion of the aorta so that a large portion of the stent-graft was visible from the duodenum. The infected graft and stent-grafts were removed in a two-part operation, from which the patient recovered satisfactorily. CONCLUSIONS: Endovascular stent-grafts may have a role to play in the management of aortoduodenal fistula, if only as a temporary measure to control bleeding.

Aged↗
PubMed2000

Adenoviral-mediated gene transfer of ICP47 inhibits major histocompatibility complex class I expression on vascular cells in vitro.

PURPOSE: Many viruses have evolved mechanisms to evade detection by the host immune system. The herpes simplex gene ICP47 encodes a protein that binds to the host antigen-processing transporter, inhibiting the formation of major histocompatibility complex class I (MHC-I) antigens in infected cells. MHC-I antigen expression is also important in acute allograft rejection. This study was designed to quantitate the effect of adenoviral-mediated gene transfer of ICP47 on MHC-I cell surface expression of human vascular cells. We hypothesized that the transduction of vascular cells with a replication-incompetent adenoviral vector that was expressing ICP47 (AdICP47) would inhibit constitutive and inducible MHC-I expression and thereby reduce the rate of cytolysis of ICP47-transduced vascular cells by sensitized cytotoxic T lymphocytes (CTL). METHODS: A replication-incompetent adenoviral vector, AdICP47, was created to express ICP47 driven by the cytomegalovirus immediate early promoter. Cultured human vascular endothelial and smooth muscle cells and human dermal fibroblasts were transduced with either AdICP47 or the control empty vector AddlE1. Cell surface constitutive and gamma-interferon-induced MHC-I expression were quantitated by flow cytometry. A standard 4-hour chromium release cytotoxicity assay was used to determine the percent cytolysis of transduced and nontransduced endothelial cells by sensitized CTL. Finally, to quantitate the specificity of the effect of ICP47 on MHC-I expression, adhesion molecule expression was quantitated in both transduced and nontransduced cells. RESULTS: Constitutive MHC-I expression in AdICP47-transduced endothelial cells was inhibited by a mean of 84% +/- 5% (SEM) in five experiments. After 48 hours of exposure to gamma-interferon, AdICP47-transduced cells exhibited a mean of 66% +/- 8% lower MHC-I expression than nontransduced cells. Similar inhibition in MHC-I expression was achieved in AdICP47-transduced vascular smooth muscle cells and dermal fibroblasts. Percent cytolysis of AdICP47-transduced endothelial cells by CTL was reduced by 72%. Finally, the specificity of the effect of transduction of ICP47 on vascular cell MHC-I expression was confirmed by a lack of significant change in either constitutive or tumor necrosis factor-induced vascular cell adhesion molecule/intercellular adhesion molecule expression. CONCLUSION: Transduction of vascular cells with AdICP47 strongly inhibits both constitutive and inducible MHC-I expression in human vascular cells. AdICP47-transduced cells exhibited a substantial reduction in cytolysis by CTL. Thus AdICP47 transduction holds promise as a technique to characterize the role of MHC-I expression in acute vascular allograft rejection in vivo and as a potential therapeutic intervention.

Adenoviridae↗
PubMed1999

Common brachiocephalic trunk: strategies for revascularization.

BACKGROUND: A common brachiocephalic trunk, in which both common carotid arteries and the right subclavian artery arise from a single trunk off the arch, is a normal variant of aortic arch branching that occurs in approximately 10% of the population. Because three of the four primary sources of cerebral blood flow arise from a single aortic branch, stenosis or occlusion of a common trunk can cause severe ischemic consequences. Common trunk revascularization has been described, but there have been no reports focusing on the management options for occlusive disease of this vascular anatomy. METHODS: A retrospective review of our experience with innominate artery revascularization identified 6 patients who underwent revascularization of a common brachiocephalic trunk between 1977 and 1997. All patients were symptomatic, with either total occlusion (n = 3) or critical stenosis (n = 3) caused by atherosclerosis (n = 5) or Takayasu's arteritis (n = 1). Revascularization was achieved by a prosthetic bypass graft from the ascending aorta to the innominate or left common carotid arteries or both (n = 5); or transarterial endarterectomy (n = 1). Concomitant endarterectomy of branch vessels was performed in 3 patients. RESULTS: There was one perioperative death from myocardial infarction, and one perioperative stroke, with death occurring 1 month after hospital discharge. One patient developed cerebral hyperperfusion syndrome 1 week after endarterectomy that resolved without sequelae with antihypertensive medications. During a follow-up period ranging from 1 to 20 years, there was one late death from congestive heart failure 5 years after operation. All surviving patients are alive and free from symptomatic recurrence. CONCLUSIONS: Revascularization for occlusive disease of a common brachiocephalic trunk can be achieved with effective and durable relief of symptoms using either a prosthetic bypass graft or endarterectomy. However, neurologic complications in 2 patients, which were fatal in 1, attest to the potential cerebral ischemic threat posed by occlusive disease of a common brachiocephalic trunk.

Adult↗
PubMed1999

Isolated inferior mesenteric artery revascularization for chronic visceral ischemia.

PURPOSE: Complete visceral artery revascularization is recommended for the treatment of chronic visceral ischemia. However, in rare cases, it may not be possible to revascularize either the celiac or superior mesenteric (SMA) arteries. We have managed a series of patients with isolated revascularization of the inferior mesenteric artery (IMA) and now report our experience gained over a period of three decades. METHODS: Records were reviewed from 11 patients with chronic visceral ischemia who underwent isolated IMA revascularization (n = 8) or who, because of failure of concomitant celiac or SMA repairs, were functionally left with an isolated IMA revascularization (n = 3). All the patients had symptomatic chronic visceral ischemia documented with arteriography. Five patients had recurrent visceral ischemia after failed visceral revascularization, and two patients had undergone resection of ischemic bowel. The celiac or the SMA was unsuitable for revascularization in five cases, and extensive adhesions precluded safe exposure of the celiac or the SMA in five cases. IMA revascularization techniques included: bypass grafting (n = 4), transaortic endarterectomy (n = 4), reimplantation (n = 2), and patch angioplasty (n = 1). RESULTS: There was one perioperative death, and the remaining 10 patients had cured or improved conditions at discharge. One IMA repair thrombosed acutely but was successfully revascularized at reoperation. The median follow-up period was 6 years (range, 1 month to 13 years). Two patients had recurrent symptoms develop despite patent IMA repairs and required subsequent visceral revascularization; interruption of collateral circulation by prior bowel resection may have contributed to recurrence in both patients. Objective follow-up examination with arteriography or duplex scanning was available for eight patients at least 1 year after IMA revascularization, and all underwent patent IMA repairs. There were no late deaths as a result of bowel infarction. CONCLUSION: Isolated IMA revascularization may be useful when revascularization of other major visceral arteries cannot be performed and a well-developed, intact IMA collateral circulation is present. In this select subset of patients with chronic visceral ischemia, isolated IMA revascularization can achieve relief of symptoms and may be a lifesaving procedure.

Angioplasty↗
PubMed1999

Pararenal aortic aneurysms: the future of open aortic aneurysm repair.

PURPOSE: As endovascular stent graft repair of infrarenal abdominal aortic aneurysms (AAAs) becomes more common, an increasing proportion of patients who undergo open operation will have juxtarenal aneurysms (JR-AAAs), which necessitate suprarenal crossclamping, suprarenal aneurysms (SR-AAAs), which necessitate renal artery reconstruction, or aneurysms with associated renal artery occlusive disease (RAOD), which necessitate repair. To determine the current results of the standard operative treatment of these patterns of pararenal aortic aneurysms, we reviewed the outcome of 257 consecutive patients who underwent operation for JR-AAAs (n = 122), SR-AAAs (n = 58), or RAOD (n = 77). METHODS: The patients with SR-AAAs and RAOD were younger (67.5 +/- 8.8 years) than were the patients with JR-AAAs (70.5 +/- 8.3 years), and more patients with RAOD were women (43% vs 21% for JR-AAAs and SR-AAAs). The patient groups were similar in the frequency of coronary artery and pulmonary disease and in most risk factors for atherosclerosis, except hypertension, which was more common in the RAOD group. Significantly more patients with RAOD had reduced renal function before surgery (51% vs 23%). Supravisceral aortic crossclamping (above the superior mesenteric artery or the celiac artery) was needed more often in patients with SR-AAAs (52% vs 39% for RAOD and 17% for JR-AAAs). Seventeen patients (7%) had undergone a prior aortic reconstruction. The most common renal reconstruction for SR-AAA was reimplantation (n = 37; 64%) or bypass grafting (n = 12; 21%) and for RAOD was transaortic renal endarterectomy (n = 71; 92%). Mean AAA diameter was 6.7 +/- 2.1 cm and was larger in the JR-AAA (7.1 +/- 2.1 cm) and SR-AAA (6.9 +/- 2.1 cm) groups as compared with the RAOD group (5.9 +/- 1.7 cm). RESULTS: The overall mortality rate was 5.8% (n = 15) and was the same for all the groups. The mortality rate correlated (P <.05) with hematologic complications (bleeding) and postoperative visceral ischemia or infarction but not with aneurysm group or cardiac, pulmonary, or renal complications. Renal ischemia duration averaged 31.6 +/- 21.6 minutes and was longer in the SR-AAA group (43.6 +/- 38.9 minutes). Some postoperative renal function loss occurred in 104 patients (40.5%), of whom 18 (7.0%) required dialysis. At discharge or death, 24 patients (9.3%) still had no improvement in renal function and 11 of those patients (4.3%) remained on dialysis. Postoperative loss of renal function correlated (P <.05) with preoperative abnormal renal function and duration of renal ischemia but not with aneurysm type, crossclamp level, or type of renal reconstruction. CONCLUSION: These results showed that pararenal AAA repair can be performed safely and effectively. The outcomes for all three aneurysm types were similar, but there was an increased risk of loss of renal function when preoperative renal function was abnormal. These data provide a benchmark for expected treatment outcomes in patients with these patterns of pararenal aortic aneurysmal disease that currently can only be managed with open repair.

Aged↗
PubMed1999

Abdominal aortic aneurysm in high-risk patients: short- to intermediate-term results of endovascular repair.

PURPOSE: To assess the safety and efficacy of endovascular repair of abdominal aortic aneurysm in high-risk patients during the short to intermediate term. MATERIALS AND METHODS: Endovascular aneurysm repair was performed in 50 patients considered too high risk for conventional repair. Stent-grafts were inserted through surgically exposed femoral arteries with fluoroscopic guidance. The anesthetic technique was epidural in 36 patients, general in 12, and local in two. Aortouniiliac stent-grafts were inserted in 42 patients and aortoaortic in eight. RESULTS: There were no deaths and no conversions to open surgical repair. The primary success rate (complete aneurysm exclusion according to CT criteria) was 88% (44 of 50). The secondary, clinical, and continuing success rates were all 98% (49 of 50). Surgical time was 196 minutes +/- 67 (mean +/- SD), blood loss was 284 mL +/- 386, and volume of contrast material administered was 153 mL +/- 64. The time from the end of the surgery to resumption of a normal diet was 0.58 days +/- 0.56, to ambulation was 1.22 days +/- 0.77, and to discharge from the hospital was 3.63 days +/- 1.60. Wound problems accounted for the majority of complications. There were no instances of pulmonary failure, renal failure, stent-graft migration, or late leakage. CONCLUSION: Endovascular repair of abdominal aortic aneurysm is feasible in two-thirds of high-risk patients, with a low mortality and high success rate during the short to intermediate term.

Aged↗