Superior Mesenteric Artery Stenting Research Articles

Computed tomography virtual intravascular endoscopy in the evaluation of fenestrated stent graft repair of abdominal aortic aneurysms

This study aimed to investigate the diagnostic value of computed tomography virtual intravascular endoscopy (VIE) in the follow-up of patients with abdominal aortic aneurysm (AAA) treated with fenestrated stent grafts. A total of 19 patients (17 males and 2 females; mean age: 75 years) with AAA undergoing fenestrated stent grafts were retrospectively studied. Pre- and post-fenestration computed tomography data were reconstructed for the generation of VIE images of aortic ostia and fenestrated stents and compared with two-dimensional axial and multiplanar reformation (MPR) images. Serum creatinine was measured pre and post fenestration to evaluate the renal function. The mean intra-aortic length measured by VIE, two-dimensional axial and MPR were 4.7, 4.4 and 4.6 mm, respectively, for the right renal stent; 5.0, 4.9 and 5.0 mm, respectively, for the left renal stent; and 5.9, 6.0 and 6.0 mm, respectively, for the superior mesenteric artery stent. Comparisons of these measurements did not show significant difference (P > 0.05). The mean diameters of renal artery ostia measured on VIE visualization pre and post fenestration were 9.2 x 8.3 and 10 x 8.9 mm for the right renal ostium; 8.3 x 7.1 and 9.9 x 8.9 mm for the left renal ostium, with significant changes observed (P < 0.01). No renal dysfunction was observed in this group. VIE is a valuable visualization tool in the follow-up of fenestrated stent graft repair of AAA by providing intraluminal appearance of fenestrated stents and measuring the length of stent protrusion.

Endovascular Therapeutic Approaches for Acute Superior Mesenteric Artery Occlusion

The purpose of this study was to characterize the outcome of attempted endovascular intervention in patients with acute embolic or thrombotic superior mesenteric artery (SMA) occlusion. The records of 21 patients during a 3-year period between 2005 and 2008 were retrieved from the in-hospital registry. The first group included 10 patients (6 women and 4 men; median age 78 years) with acute embolic occlusion of the SMA. The median duration of symptoms from symptom onset to angiography was 30 hours (range 6 to 120). Synchronous emboli (n = 12) occurred in 6 patients. Embolus aspiration was performed in 9 patients, and 7 of these had satisfactory results. Complementary local thrombolysis was successful in 2 of 3 patients. Residual emboli were present at completion angiography in all 7 patients who underwent successful aspiration embolectomy, and bowel resection was necessary in only 1 of these patients. One serious complication occurred because of a long SMA dissection. The in-hospital survival rate was 90% (9 of 10 patients). The second group included 11 patients (10 women and 1 man; median age 68 years) with atherosclerotic acute SMA occlusions. The median time of symptom duration before intervention was 97 hours (range 17 to 384). The brachial, femoral, and SMA routes were used in 6, 7, and 5 patients, respectively. SMA stenting was performed through an antegrade (n = 7) or retrograde (n = 3) approach. Bowel resection was necessary in 4 patients. No major complications occurred. The in-hospital survival rate was 82% (9 of 11 patients). Endovascular therapy of acute SMA occlusion provides a good alternative to open surgery.

Duplex criteria for native superior mesenteric artery stenosis overestimate stenosis in stented superior mesenteric arteries

Superior mesenteric artery (SMA) duplex scanning is utilized to screen for high-grade (>or=70%) SMA stenosis (peak systolic velocity [PSV] >or=275 cm/second) and for follow-up of SMA bypass grafts and stents. Expected duplex scan findings in SMA bypass grafts have been recently reported. There is, however, little information correlating duplex scans from stented SMAs to procedural angiograms in patients treated for high-grade (>or=70%) SMA stenosis. We report validation of duplex scan criteria for high-grade native artery SMA stenosis, and also duplex scan examined results after SMA stent placement correlated with angiograms and angiographic measured pressure gradients pre- and post-SMA stent placement. Thirty-five patients with symptoms consistent with mesenteric ischemia were treated with SMA stents. Pre-intervention angiography demonstrated >70% SMA stenosis or SMA occlusion in all but 3 patients. Pre-intervention pressure gradients were obtained in 20 stenotic but patent SMAs and averaged 57 +/- 38 mm Hg; range, 15 to 187 mm Hg. Eighteen of the patients had SMA duplex scan prior to angiography, and 17 demonstrated an SMA PSV >or=275 cm/second or no flow, (mean 450 +/- 152 cm/second in patent arteries; range, 256 to 770 cm/second). Post-stent placement angiography demonstrated <30% SMA stenosis in all 35 patients. Post-stent pressure gradients were obtained in 22 patients and averaged 11 +/- 13 mm Hg; range, 0 to 45 mm Hg, (P < .001 compared to pre-stent pressure gradients in a paired test) and were elevated in patients with >or=60% celiac artery stenosis compared with those with <60% celiac artery stenosis (P < .006). Mean early post-stent duplex PSV scans obtained in 13 patients, were 336 +/- 45 cm/second; range, 279 to 416 cm/second (P = .011 compared to pre-stent PSVs). SMA stenting provides good anatomic results and significantly reduces measured pressure gradients. Duplex scans measured SMA PSVs are reduced post-stent placement but despite good angiographic results remain above criteria predicting high-grade native artery SMA stenosis. Duplex scan criteria developed to identify high-grade native artery SMA stenosis accurately predict high-grade native artery SMA stenosis but overestimate stenosis in stented SMAs. New duplex scan criteria are required to predict high-grade stenosis in stented SMAs.

Reperfusion Hemorrhage Following Superior Mesenteric Artery Stenting

Percutaneous transluminal angioplasty and stent placement is now an established treatment option for chronic mesenteric ischemia and is associated with low mortality and morbidity rates. We present a case of reperfusion hemorrhage complicating endovascular repair of superior mesenteric artery stenosis. Although a recognized complication following repair of carotid stenosis, hemorrhage has not previously been reported following mesenteric endovascular reperfusion. We describe both spontaneous cessation of bleeding and treatment with coil embolization.

Retrograde mesenteric stenting during laparotomy for acute occlusive mesenteric ischemia

Acute mesenteric ischemia (AMI) caused by arterial occlusive disease requires prompt diagnosis and revascularization to avoid the high mortality associated with this disease. In an attempt to minimize the magnitude of operation for arterial occlusive AMI, we have developed a new technique of endovascular recanalization and open retrograde stenting of the superior mesenteric artery (SMA) during laparotomy so that the bowel can also be assessed and resected if necessary. All emergent mesenteric revascularizations for arterial occlusive AMI performed at Dartmouth-Hitchcock Medical Center from 2001 to 2005 (n = 13) were retrospectively reviewed. Outcomes were analyzed with respect to the method of revascularization and other perioperative variables. Restenosis was evaluated with duplex ultrasound imaging. Three different revascularization methods were used: surgical bypass (n = 5), antegrade percutaneous stenting (n = 2), and retrograde open mesenteric (SMA) stenting (ROMS, n = 6). Satisfactory revascularization was achieved in all cases and all methods. ROMS was successfully accomplished in three of six patients after antegrade attempts to cross the SMA from the arm were unsuccessful. At 17%, the ROMS group had the lowest hospital mortality compared with bypass at 80% (P = .08) and percutaneous stent at 100% (P = .11). All five of the surviving patients treated with ROMS were discharged to home after a mean hospital stay of 20 days (range, 6 to 38 days). During a mean follow-up of 13 +/- 7 months, three patients died of unrelated causes, of which two were being followed with asymptomatic recurrent SMA stenosis detected by duplex scan. The two surviving patients are alive and well, but one has required percutaneous SMA stenting of a progressive asymptomatic restenosis. Retrograde open SMA stenting during laparotomy for AMI has a high technical success rate and provides an attractive alternative to surgical bypass in these often critically ill patients. Because it is combined with open laparotomy, it honors the essential surgical principles of evaluating and resecting nonviable bowel. Restenosis rates appear to be high, so that patients must be followed closely. Further study and development of this new hybrid technique is warranted.

ENDOVASCULAR REPAIR OF CHRONIC MESENTERIC OCCLUSIVE DISEASE: THE ROLE OF DUPLEX SURVEILLANCE

Chronic occlusive mesenteric ischaemia can be treated surgically or endovascularly. Endovascular techniques as elsewhere in the vascular tree are limited by restenosis. The aim of this study was to determine if duplex ultrasound proven restenosis correlates with recurrence of symptoms. Our study looks at successful percutaneous revascularization of the mesenteric circulation associated proven restenosis using colour Doppler ultrasound and the relation to recrudescence of symptoms or weight loss. A retrospective review of five patients treated endovascularly at our institution for mesenteric angina secondary to visceral artery stenosis was carried out. Technical success was achieved in four out of the five patients in our study. One patient had a procedure complicated by thrombus in the coeliac axis and superior mesenteric artery (SMA) stents, subsequently showed SMA occlusion and 90% stenosis of the CA and inferior mesenteric artery and required an aorto-mesenteric graft. Three of the four patients with a technically successful procedure had significant (>70%) restenosis of the SMA. All three, including one patient with both SMA restenosis and chronic inferior mesenteric artery occlusion, remain asymptomatic and have maintained their postprocedural weight gain. Although ultrasound is a convenient, non-invasive tool for follow up of endovascular treatment of mesenteric stenosis, its use is unclear as in our study restenosis did not correlate with recrudescence of symptoms.