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Biomedical subjects

R A Baum

Publications and source records attributed to R A Baum.

At least 19 recordsLinked to original sources
PubMed2001

Endovascular AAA repair in patients with renal insufficiency: strategies for reducing adverse renal events.

Vascular imaging, usually employing nephrotoxic contrast agents is relied upon for all aspects of endovascular AAA repair causing some to consider renal insufficiency a relative contraindication. We sought to determine if endovascular AAA evaluation and repair could be successfully accomplished by minimally or non-nephrotoxic modalities. Records and results for 98 consecutive patients undergoing endovascular AAA repair were reviewed. Patients requiring dialysis preoperatively were excluded (N=3). The average volume of iodinated contrast agent employed for intraoperative imaging was 152 cc (35-420 cc). Twenty patients (20%) had baseline renal insufficiency (serum creatinine > or =1.3 mg/dl). A rise in serum creatinine above baseline was observed in 23 (24%) patients following repair; for 15 (16%) this was permanent. Creatinine rise occurred in patients with both normal (15) and abnormal (8) baseline values (P=0.09). Rise in creatinine was independent of contrast volume employed and of the use of infrarenal vs suprarenal device fixation (P>0.05). Two (2%) patients required permanent dialysis, one of which had a normal baseline creatinine and unclear etiology for renal failure, the other had a baseline creatinine of 2 and required device placement over an accessory renal artery. Strategies to minimize the use of nephrotoxic contrast for patients with renal insufficiency included the use of MRA, rather than contrast-CT for pre and postoperative imaging (7, 35%) and use of Gadolinium rather than iodinated contrast for performance of intraoperative arteriography (5, 25%). Endovascular grafts were successfully designed and implanted based upon MRA as the sole preoperative imaging modality in every case in which it was attempted (7). Mortality was not significantly different between those with and without abnormal baseline renal function (P>0.05). Adverse events (access failures, arterial injuries, blood loss, endoleaks) were not significantly correlated with baseline renal insufficiency, rise in creatinine from baseline, use of MRA or intraoperative Gadolinium angiography (P>0.05).Pre- and postoperative evaluation and performance of endovascular AAA repair can be accomplished in patients with renal insufficiency without increasing the rate of mortality or adverse events employing a strategy which minimizes the use of nephrotoxic contrast agents, relying upon Gadolinium arteriography and MRA. Endovascular grafts can be successfully planned and followed employing MRA as the sole imaging modality.

Aortic Aneurysm, Abdominal↗
PubMed2001

Balloon embolization of the internal iliac artery before aneurysm endograft deployment.

Six patients, ranging from 69 to 81 years of age, underwent iliac artery embolization with use of Detachable Silicon Balloons (DSB) 11-14 days before stent-graft repair of aneurysms. Balloons of 8.8-mm, 9.4-mm, and 9.9-mm sizes were used with 20-30 g of release force. Deployment difficulty was experienced in three cases. Five of six cases were successful, with the iliac artery remaining occluded at the time of endografting; one case required subsequent coil replacement. The average operative time for balloon embolization (75 min +/- 28) was shorter than that in 18 cases of coil embolization performed within the same time period (111 min +/- 105), but the difference was not significant (P = .21). Postoperatively, one patient (17%) reported buttock claudication after the procedure. Use of the DSB represents an alternative to use of coils for embolization of large and tortuous iliac arteries.

Aged↗
PubMed2001

Upper gastrointestinal hemorrhage and transcatheter embolotherapy: clinical and technical factors impacting success and survival.

PURPOSE: To identify clinical and technical factors influencing the outcome of transcatheter embolotherapy for nonvariceal upper gastrointestinal (GI) hemorrhage and to quantify the impact of successful intervention on patient survival. MATERIALS AND METHODS: A retrospective review was performed of all patients (n = 163) who underwent arterial embolization for acute upper GI hemorrhage at a university hospital over an 11.5-year period. Clinical success was defined as target area devascularization that resulted in the clinical cessation of bleeding and stabilization of hemoglobin level. The clinical condition of each patient at intervention was defined by history, laboratory examination, and two composite indicator variables. With use of logistic regression, the dependent variable, clinical success, was modeled on two categories of clinical and technical variables. A final model regressed patient survival on clinical success and other clinical variables. RESULTS: None of the procedural variables analyzed had a significant influence on clinical success. Several clinical variables did impact clinical success, including multiorgan system failure (OR, 0.36; P =.030), coagulopathy (OR, 0.36; P =.026), and bleeding subsequent to trauma (OR, 7.1; P =.040) or invasive procedures (OR, 6.5; P =.009). Regardless of their clinical condition at intervention, patients who underwent clinically successful embolization were 13.3 times more likely to survive than those who had an unsuccessful procedure (CI, 4.54-39.2; P =.000). Nevertheless, patients with multiorgan system failure were 17.5 times more likely to die, independent of the outcome of the procedure (CI, 0.014-0.229; P =.000). CONCLUSION: Arresting nonvariceal upper GI hemorrhage with transcatheter embolotherapy has a large positive effect on patient survival, independent of clinical condition or demonstrable extravasation at intervention. Aggressive treatment with transcatheter embolotherapy is advisable in patients with acute nonvariceal upper GI hemorrhage.

Adult↗
PubMed2001

Risk factors for liver abscess formation after hepatic chemoembolization.

PURPOSE: To assess the frequency and risk factors for liver abscess after hepatic chemoembolization. MATERIALS AND METHODS: The authors performed retrospective analysis of 397 chemoembolization procedures in 157 patients. All patients received prophylactic intravenous antibiotics before the procedure and 5 days of oral antibiotics after the procedure. The association between abscess formation and risk factors was determined with use of chi(2) analysis and the Fisher exact test and expressed as an odds ratio. RESULTS: Liver abscess occurred in seven of 157 patients (4.5%) after eight of 397 procedures (2.0%) at a mean of 19 d +/- 7 after chemoembolization. No patients had neutropenia. Organisms isolated reflected intestinal flora. Six patients required percutaneous drainage for 35 d +/- 29. The seventh patient required drainage for the remainder of life as a result of a nonhealing biliary fistula. Three of 24 patients with neuroendocrine tumors had abscesses (12.5%; odds ratio, 4.6; 95% CI, 0.96-22.1; P =.07), as did three of 14 patients with gastrointestinal sarcomas (21%; odds ratio, 9.5; 95% CI, 1.9-47.8; P =.016), and one of two with pancreatic adenocarcinoma. Six of the seven patients with abscesses underwent a Whipple procedure before chemoembolization. Only one patient with a history of a Whipple procedure did not develop an hepatic abscess. In the absence of a bilioenteric anastomosis, abscess occurred in only one of 150 patients (0.7%), or one of 383 procedures (0.3%). The odds ratio for liver abscess among patients with a bilioenteric anastomosis was 894 (95% CI, 50-16,000; P <.0001). CONCLUSION: Earlier bilioenteric anastomosis is the major determinant of liver abscess formation after hepatic chemoembolization. The prophylaxis regimen used failed to prevent abscess formation in patients with earlier bilioenteric anastomosis.

Adult↗
PubMed2001

Sarcomas metastatic to the liver: response and survival after cisplatin, doxorubicin, mitomycin-C, Ethiodol, and polyvinyl alcohol chemoembolization.

PURPOSE: To evaluate the response to and survival after chemoembolization with cisplatin, doxorubicin, mitomycin-C, Ethiodol, and polyvinyl alcohol for patients with sarcomas metastatic to the liver that are surgically unresectable. MATERIALS AND METHODS: Sixteen patients were treated. Primary tumors included 11 gastrointestinal leiomyosarcomas, two splenic angiosarcomas, one leiomyosarcoma of the broad ligament, one leiomyosarcoma of the inferior vena cava, and one malignant fibrous histiocytoma of the colon. Chemoembolization with cisplatin, doxorubicin, mitomycin-C, Ethiodol, and polyvinyl alcohol particles was performed 1-5 times at approximately monthly intervals (mean, 2.8). Pre- and posttreatment cross-sectional imaging was performed 1 month after completion of treatment and then every 3 months. Thirty-day response was graded according to World Health Organization/Eastern Cooperative Oncology Group criteria. Survival was calculated with use of Kaplan-Meier analysis. RESULTS: Two patients (13%) exhibited partial morphologic response, 11 patients (69%) were morphologically stable, and three (19%) demonstrated progression of disease 30 days after completion of treatment. Among the 13 responders, two underwent partial hepatectomy after initial treatment. Seven developed intrahepatic progression at a mean of 10 months and a median time of 8 months. The remaining four patients had no documented intrahepatic progression at the time of last imaging follow-up. Nine patients developed extrahepatic progression at a mean time of 6.3 months and a median time of 6 months, of whom four underwent additional surgical resection. Response to therapy was based on time of first intervention. Cumulative survival from time of diagnosis with use of Kaplan-Meier analysis was 81% at 1 year, 54% at 2 years, and 40% at 3 years. Median survival time was 20 months. Cumulative survival from initial chemoembolization was 67% at 1 year, 50% at 2 years, and 40% at 3 years, with a median survival time of 13 months. The thirty-day mortality rate was zero. CONCLUSION: Durable tumor response with chemoembolization is possible in this form of metastatic disease, which is highly resistant to systemic chemotherapy.

Chemoembolization, Therapeutic↗
PubMed2001

Diagnosis and management of type 2 endoleaks after endovascular aneurysm repair.

Endovascular repair is a major treatment advance in patients with large infrarenal abdominal aortic aneurysms. Since the FDA approved two commercial devices 2.5 years ago, over 40,000 patients have undergone this procedure in the United States. Although we have learned a great deal, more than a few mysteries relating to the long-term performance of these devices remain. This results in never-ending surveillance protocols searching for graft failure and aneurysm expansion. One of the especially contentious issues is the management of type 2 endoleaks. Unlike other endoleaks that are related to problems with the graft and/or fixation, this type of leak occurs in patients with properly functioning devices. This is why so much controversy exists about whether or not these patients must be treated. Some advocate "watchful-waiting" intervention only when there is aneurysm expansion. Others routinely treat patients with type 2 endoleaks in an attempt to prevent expansion. As with most controversial topics, if you look carefully, there is more agreement than disagreement between the two groups. In this review, we will first describe the methods used for endoleak diagnosis and treatment. We will then review our current endoleak treatment algorithm and explain its rationale for use.

Algorithms↗
PubMed2001

Aneurysm sac pressure measurements after endovascular repair of abdominal aortic aneurysms.

OBJECTIVES: The goal of endovascular grafting of abdominal aortic aneurysms (AAAs) is to exclude the aneurysm sac from systemic pressure and thereby decrease the risk of rupture. Unlike conventional open surgery, branch vessels in the sac (eg, lumbar artery and inferior mesenteric artery [IMA]) are not ligated and can potentially transmit pressure. The purpose of our investigation was to evaluate the feasibility of various interventional techniques for measuring pressure within the aneurysm sac in patients who had undergone endovascular repair of AAAs. METHODS: Sac pressure measurements were performed in 21 patients who had undergone stent graft repair of AAAs. Seventeen of 21 patients had endoleaks demonstrated on 30-day computed tomographic (CT) scans. Access to the aneurysm sac in these patients was through direct translumbar sac puncture (5 patients), through a patent IMA accessed via the superior mesenteric artery (SMA) (9 patients), or by direct cannulation around attachment sites (3 patients). Four patients had perioperative pressure measurements obtained through catheters positioned along side of the endovascular graft at the time of its deployment. Two of these catheters were left in position for 30 hours during which time CT and conventional angiography were performed. Pressures were determined with standard arterial-line pressure transduction techniques and compared with systemic pressure in each patient. RESULTS: Elevated sac pressure was found in all patients. The sac pressure in patients with endoleaks was found to be systemic (15 patients) or near systemic (2 patients) and all had pulsatile waveforms. Elevated sac pressures were also found in patients without CT or angiographic evidence of endoleak (2 patients). Injection of the sacs in two of these patients revealed a patent lumbar artery and an IMA. CONCLUSIONS: It is possible to measure pressures from within the aneurysm sac in patients with stent grafts with a variety of techniques. Patients may continue to have pressurized AAA sacs despite endovascular AAA repair. Endoleaks transmit pulsatile pressure into the aneurysm sac regardless of the type. It is possible to have systemic sac pressures without evidence of endoleaks on CT or angiography.

Angioplasty, Balloon↗
PubMed2001

Gender-related differences in infrarenal aortic aneurysm morphologic features: issues relevant to Ancure and Talent endografts.

PURPOSE: The purpose of this study was to determine whether gender-related anatomic variables may reduce applicability of aortic endografting in women. METHODS: Data on all patients evaluated at our institution for endovascular repair of their abdominal aortic aneurysm were collected prospectively. Ancure (Endovascular Technologies (EVT)/Guidant Corporation, Menlo Park, Calif) and Talent (World Medical/Medtronic Corporation, Sunrise, Fla) endografts were used. Preoperative imaging included contrast-enhanced computed tomography and arteriography or magnetic resonance angiography. RESULTS: One hundred forty-one patients were evaluated (April 1998-December 1999), 19 women (13.5%) and 122 men (86.5%). Unsuitable anatomy resulted in rejection of 63.2% of the women versus only 33.6% of the men (P = .026). Maximum aneurysm diameter in women and men were similar (women, 56.94 +/- 8.23 mm; men, 59.29 +/- 13.22 mm; P = .5). The incidence of iliac artery tortuosity was similar across gender (women, 36.8%; men, 54.9%; P = .2). The narrowest diameter of the larger external iliac artery in women was significantly smaller (7.29 +/- 2.37 mm) than in men (8.62 +/- 2.07 mm; P = .02). The proximal neck length was significantly shorter in women (10.79 +/- 12.5 mm) than in men (20.47 +/- 19.5 mm; P = .02). The proximal neck width was significantly wider in women (30.5 +/- 2.4 mm) than in men (27.5 +/- 2.5 mm; P = .013). Proximal neck angulation (>60 degrees) was seen in a significantly higher proportion of women (21%) than men (3.3%; P = .012). Of the patients accepted for endografting, a significantly higher proportion of women required an iliofemoral conduit for access (women, 28.6%; men, 1.2%; P = .016). CONCLUSION: Gender-related differences in infrarenal aortic aneurysm morphologic features may preclude widespread applicability of aortic endografting in women, as seen by our experience with the Ancure and Talent devices. In addition to a significantly reduced iliac artery size, women are more likely to have a shorter, more dilated, more angulated proximal aortic neck.

Aged↗
PubMed2001

The role of magnetic resonance angiography for endoprosthetic design.

OBJECTIVES: Many patients with aortic aneurysms have renal insufficiency and may be at increased risk when conventional imaging modalities (contrast-enhanced computed tomography and arteriography) are used for aortic endograft design. Our objective was to determine if magnetic resonance angiography (MRA) could be used as the sole imaging modality for endoprosthetic design. METHODS: A total of 96 consecutive patients who underwent endovascular repair of thoracic (5) and abdominal (91) aortic aneurysms (April 1998-December 1999) were included in this study. Data were collected prospectively. Gadolinium-enhanced MRA was used preoperatively in place of conventional imaging if renal insufficiency or a history of severe contrast reaction was present. The control group underwent conventional imaging. Endografts used included Ancure, AneuRx, and Talent. RESULTS: Fourteen patients (14.6%) had their endografts designed solely with MRA. Intraoperative access failure; proximal and distal extensions (unplanned); conversion to open, aborted procedures; and endoleaks occurred with equal frequency in both the MRA-designed and control groups (16.7% vs 18.3%, respectively; P =.33). Despite baseline renal insufficiency, there was no significant rise in the creatinine level after endograft implantation in patients with an MRA design (preoperative level, 1.8; postoperative level, 1.9; P =.5). CONCLUSION: MRA may be successfully used as the sole modality for aortic endograft design. The use of MRA for this purpose is noninvasive and minimizes nephrotoxic risk.

Aortic Dissection↗
PubMed2001

Failure of endovascular abdominal aortic aneurysm graft limbs.

OBJECTIVE: Endovascular abdominal aortic aneurysm (AAA) grafts are subject to subsequent failure of endograft limbs. We sought to determine what device-related factors could be identified that might contribute to limb failure. METHODS: We reviewed the records of patients who had undergone endovascular AAA repair and femorofemoral bypass grafting at a single institution. RESULTS: Endovascular AAA repair was performed in 173 patients. There were 137 bifurcated endografts and 36 aortomonoiliac grafts combined with femorofemoral bypass grafts, yielding a total population of 310 aortic graft limbs and 36 femorofemoral grafts. Thirty-nine additional patients underwent femorofemoral bypass grafting for occlusive disease. The cumulative primary patency of all endografts performed for AAA was 92% at 21 months. Secondary patency was achieved for all failed endograft limbs. There were 24 aortic graft limb "failures" that required intervention: seven limbs underwent thrombosis requiring revision; kinked limbs requiring stenting either at the time of graft placement (17) or subsequently (7) were identified. Fully supported endograft limbs had better primary patency (97% at 18 months) than unsupported limbs (69% at 18 months, P <.001). The aortomonoiliac grafts with femorofemoral bypass grafts tended to have better patency (97% at 18 months) than bifurcated endografts (90% at 18 months), but this did not reach statistical significance (P =.28, not significant). Femorofemoral grafts performed for occlusive disease were found to have somewhat lower patency than those performed for AAA (83% vs 92% at 18 months of follow-up, P =.37, not significant). CONCLUSIONS: Fully supported AAA endografts provide superior endograft limb patency compared with unsupported designs. Consideration should be given to routine stenting of all unsupported endograft limbs. Aortomonoiliac grafts and bifurcated grafts provide similar results for endograft limb patency. Femorofemoral bypass grafts performed in conjunction with aortomonoiliac grafts for AAA disease provide excellent short-term patency.

Adult↗
PubMed2001

Impact of exclusion criteria on patient selection for endovascular abdominal aortic aneurysm repair.

PURPOSE: Wide-ranging predictions have been made about the usefulness of endovascular repair for patients with abdominal aortic aneurysms (AAAs). The availability of US Food and Drug Administration-approved devices has removed the restrictions on patient selection, which had been controlled by device trials. This study examined the applicability of endovascular AAA repair and identified the anatomic barriers to successful endovascular AAA repair that should guide future device development. METHODS: All patients who came to our institution for infrarenal AAA repair between April 1998 and June 2000 were offered evaluation for endovascular repair. Thin-cut spiral computed tomography scans and arteriograms were obtained on all patients, and their anatomic characteristics were prospectively entered into a database. A wide selection of available devices allowed the treatment of diverse AAA anatomic features. RESULTS: A total of 307 patients were examined (264 men, 43 women). Of these, 204 patients (66%; 185 men, 19 women) underwent endovascular repair, and 103 patients (34%, 79 men, 24 women) were rejected. Reasons for exclusion included short aneurysm neck (56, 54%), inadequate access because of small iliac arteries (48, 47%), wide aneurysm neck (41, 40%), presence of bilateral common iliac aneurysms extending to the hypogastric artery (22, 21%), excessive neck angulation (14, 14%), extensive mural thrombus in the aneurysm neck (10, 10%), extreme tortuosity of the iliac arteries (10, 10%), accessory renal arteries originating from the AAA (6, 6%), malignancy discovered during the examination (5, 5%), and death during the examination interval (2, 2%). Rejected patients had an average of 1.9 exclusion criteria (range, 1 to 4). A disproportionate number of women were excluded because of anatomic findings (P = .0009). Although 80% of patients who were at low risk for surgery qualified for endovascular repair, only 49% of our patients who were at high risk for surgery were acceptable candidates (P < .001). Of the 103 patients who were excluded, 34 (33%) underwent open surgical repair, and the remaining 69 (67%) were deemed to be unfit for open surgery. Three patients (1.4%) failed endograft placement because of inadequate vascular access. CONCLUSION: Most infrarenal AAAs (66%) can be treated with endovascular devices currently available commercially or through US Food and Drug Administration-approved clinical trials. However, patients who are at high risk for surgery and might benefit most from endovascular repair are less likely to qualify for the procedure (49%). Men (70%) are more likely than women (40%) to meet the anatomic criteria for endografting. Difficulties with vascular access and attachment site geometry predominate as reasons for exclusion. Our findings suggest that smaller profile devices, which can negotiate small and tortuous iliac arteries, are needed. Proximal and distal attachment site problems require devices that can accommodate wide and angulated attachment necks and achieve short seal zones.

Aged↗
PubMed2001

Carotid MR angiography: phase II study of safety and efficacy for MS-325.

PURPOSE: To evaluate the safety and efficacy of MS-325 in patients suspected of having carotid arterial disease. MATERIALS AND METHODS: Fifty carotid arteries in 26 patients were imaged with three-dimensional spoiled gradient-recalled-echo magnetic resonance (MR) angiography at 5 and 50 minutes after injection of MS-325. MS-325 was administered intravenously as a single dose of 0.01, 0.03, or 0.05 mmol per kilogram of body weight as determined with a dose randomization scheme for four, nine, and 13 patients, respectively. Safety, including clinical laboratory changes and electrocardiographic monitoring, was assessed until approximately 3 days after injection. Conventional contrast agent-enhanced angiography was used as the standard of reference. Independent readers blinded to the dose interpreted the MR angiographic and conventional images. Images were assessed for location and extent of carotid arterial stenosis. RESULTS: There were no severe or serious adverse events. For the determination of clinically significant stenosis (>70%) on the 5-minute images, sensitivity, specificity, and accuracy (P =.07, three-way comparison) were 100%, 100%, and 100%; 63%, 100%, and 88%; and 40%, 75%, and 55% at 0.01, 0.03, and 0.05 mmol/kg, respectively. Sensitivity and specificity for images at 50 minutes after MS-325 administration showed the same trends as the 5-minute images. CONCLUSION: Overall accuracy for MS-325-enhanced carotid MR angiography performed during steady-state conditions of circulating contrast agent approximately 5 minutes after injection was high (88%-100%) at 0.03 and 0.01 mmol/kg. MS-325 was well tolerated at all evaluated doses.

Carotid Stenosis↗
PubMed2001

Pulmonary arteriovenous malformations: three-dimensional gadolinium-enhanced MR angiography-initial experience.

PURPOSE: To determine whether three-dimensional gadolinium-enhanced magnetic resonance (MR) angiography could be used to identify pulmonary arteriovenous malformations (PAVMs) and to accurately identify the size and number of feeding arteries. MATERIALS AND METHODS: Eight patients suspected of having PAVM were examined with three-dimensional MR angiography at 1.5 T. Images were reviewed by a single radiologist blinded to conventional angiographic findings who evaluated each image for the size, number, and location of PAVMs, as well as for the size and number of feeding arteries. Five patients underwent conventional angiography with embolization therapy, and one patient underwent lobectomy. Two patients did not undergo either surgery or angiography. RESULTS: Three-dimensional MR angiography revealed nine (90%) of 10 PAVMs that were confirmed at conventional angiography (n = 9) or examination of a surgical specimen (n = 1). The single PAVM that was not identified prospectively at MR angiography was small (3-4 mm) and peripheral. Two additional PAVMs were identified in the two patients who did not undergo surgery or angiography. CONCLUSION: Three-dimensional MR angiography is a promising technique for use in the diagnosis of PAVM, although small (<5-mm) PAVMs may be more difficult to identify with the technique. The technique is a particularly useful means of noninvasively demonstrating the size and number of feeding arteries prior to treatment.

Adolescent↗
PubMed2000

Limb kinking in supported and unsupported abdominal aortic stent-grafts.

PURPOSE: The occurrence of kinking of stent-graft limbs depends on the patient's anatomy and the device used. The purpose of this investigation was to determine the rates of limb kinking in supported and unsupported aortic stent-grafts. MATERIALS AND METHODS: The authors performed a retrospective review of patients undergoing placement of either a Guidant Ancure/EGS or Medtronic Talent aortic stent-graft for the treatment of abdominal aortic aneurysm as part of separate phase II and phase III clinical trials. The records of 91 consecutive patients with 149 limbs were reviewed. The type and configuration of each device and any procedure performed specifically relating to limb patency was recorded. An analysis was then performed comparing the rates of kinking in supported and unsupported groups. A review of the literature was also performed. RESULTS: Overall, there was kinking in 18 of 149 limbs (12%). In the supported stent-graft group, 48 bifurcated and 26 aortomonoiliac grafts were placed, with a total of 122 limbs at risk. Six limbs (5%) in five patients required intervention as a result of limb kinking. Stents were placed intraoperatively in two limbs (2%) and postoperatively in four limbs (3%) for thrombosis or severe stenosis. In the unsupported group, 12 bifurcated and three aortomonoiliac grafts were placed, with a total of 27 limbs at risk. Twelve limbs (44%) in eight patients required some type of intervention as a result of limb kinking. Stents were placed intraoperatively in seven limbs (26%) and postoperatively in five limbs (19%) for thrombosis or severe stenosis. Rates of limb kinking were significantly different between the supported and unsupported groups (P < .0001). CONCLUSIONS: The use of supported versus unsupported stent-grafts impacts the occurrence of limb kinking. A direct comparison of the groups suggests that an unsupported stent-graft will be more than 15 times more likely than a supported system to require intervention because of kinking.

Angiography↗
PubMed2000

Relationship between preoperative patency of the inferior mesenteric artery and subsequent occurrence of type II endoleak in patients undergoing endovascular repair of abdominal aortic aneurysms.

OBJECTIVES: The purpose of this study was (1) to find out whether preoperative inferior mesenteric artery (IMA) patency (on radiographic imaging) predicts IMA-related endoleaks after endovascular repair of infrarenal abdominal aortic aneurysms, (2) to determine feasibility of measuring aneurysm sac pressures in patients with endoleaks, and (3) to report early evidence of effective endovascular obliteration of IMA endoleaks. METHODS: We studied 76 consecutive cases of infrarenal aortic aneurysms that were repaired with an endovascular approach (March 1998-April 1999). RESULTS: There were 13 (17%) endoleaks persistent 30 days after the procedure. Eleven (85%) of these 13 were IMA-related endoleaks, which were documented with selective superior mesenteric artery angiography. The preoperative finding (on computed tomographic scan) of a patent IMA does not always predict an IMA-related endoleak, but results in a statistically and clinically significant higher ratio of patients with IMA-related endoleaks in the immediate postoperative period (24% versus 3%, P <.035). In eight of the 11 patients with persistent IMA-related endoleaks, measurement of intra-aneurysm sac pressures was possible, and six of these patients had systemic pressures within the excluded aneurysm sac. Nine (82%) of 11 IMA-related endoleaks were successfully obliterated by means of selective IMA embolization. CONCLUSIONS: Many endoleaks are caused by a patent IMA, and this can result in persistence of systemic pressure within the aneurysm sac. The preoperative finding (on computed tomographic scan) of a patent IMA is a predictor of increased rates of IMA endoleaks, and IMA endoleaks can be successfully obliterated through endovascular procedures, after endovascular abdominal aortic aneurysm repair.

Aortic Aneurysm, Abdominal↗