Biomedical subjects
Mark C Bates
Publications and source records attributed to Mark C Bates.
Occult popliteal artery stenosis masquerading as atheroemboli in a patient with previous knee replacement.
The purpose of this article is to report the unusual presentation of a 63-year-old patient with Rutherford grade 2, category 5 tissue ischemic changes involving the right foot secondary to an occult popliteal stenosis that was obscured behind a prosthetic knee on diagnostic angiograms. Conventional abdominal angiography with bilateral lower extremity runoff showed no evidence of significant disease and the patient was misdiagnosed with atheroemboli syndrome secondary to ipsilateral common femoral access following recent catheterization. Ultimately, a meticulous physical examination disclosed a bruit in the right popliteal fossa and selective right leg angiography with oblique views confirmed eccentric complex luminal encroachment in the right popliteal artery that was eclipsed by a prosthetic knee on antecedent nonselective angiography. The lesion responded favorably to endovascular treatment with durable clinical improvement. This case illustrates the importance of a meticulous physical examination and noninvasive studies prior to angiography in patients with ischemic tissue changes and emphasizes the importance of oblique views to image any vessel that may be obscured by a metal prosthesis.
Functional and clinical outcomes of nitinol stenting with and without abciximab for complex superficial femoral artery disease: a randomized trial.
OBJECTIVE: To evaluate the effect of glycoprotein IIb/IIIa inhibition during nitinol stenting, of superficial femoral occlusive disease. BACKGROUND: Stent implantation in the superficial femoral artery has been associated with suboptimal results while Glycoprotein IIb/IIIa inhibitors have shown improved procedural results during coronary intervention. We evaluated abciximab infusion during (Smart Stent) implantation in superficial femoral obstructions. METHODS: We conducted a randomized placebo controlled trial. The two primary end points include: (1) 9-month restenosis defined as a decrease in ankle brachial index and in-stent duplex ultrasound restenosis: (2) adverse events defined as death (30 days) or repeat revascularization within 9 months. RESULTS: Twenty-seven patients were randomized to abciximab and 24 patients to control (placebo). The primary end point of cumulative restenosis occurred in 15.4% of patients administered abciximab and in 12% administered placebo (P = 0.873). The primary restenosis endpoint in diabetics and total occlusions were similar at 14.3% and 15.4% respectively. The composite end point of 30-day mortality and 9-month revascularization occurred in 5.8% abciximab and 0% (P = 0.274) placebo with no 30-day deaths. Graded treadmill time and Rutherford class were all significantly improved in both groups, but the abciximab group did not appear to demonstrate any identifiable effect. CONCLUSION: (Smart Stent) nitinol stenting of the superficial femoral artery was associated with favorable functional outcomes at 9 months. Adjunctive abciximab did not appear to demonstrate any identifiable effect.
Renal artery angiography: "the right ipsilateral oblique" myth.
BACKGROUND: Finding the optimal image intensifier angle of obliquity during renal intervention is important for accurate stent placement but can require multiple catheter rotations and test injections of contrast. OBJECTIVE: Explore the usefulness of axial magnetic resonance angiography (MRA) as a roadmap for predicting image intensifier position during subsequent renal intervention. METHODS: MRA images were reviewed in 137 consecutive patients (255 renal arteries) undergoing workup for renal artery stenosis. The axial angle of renal artery incidence perpendicular to the spine was estimated by two operators and results averaged. RESULTS: The average angle of incidence for the renal artery ostia was +21.24 degrees +/-2.31 degrees for the right and +8.81 degrees +/-2.0 degrees for the left (P < .0001). The positive numbers correlate with left anterior oblique (LAO) and negative right anterior oblique (RAO). CONCLUSIONS: MRA can be used to define the origin of the renal artery and is most likely to predict an LAO image window for subsequent angiography of the left and right renal arteries displacing the "ipsilateral oblique" axiom. In patients without baseline MRA the 10 to 20 degree LAO "empiric" position will allow coaxial imaging of both renal ostia in 75% of cases. However, there can be extreme variation in the renal origin (53 degrees RAO to 85 degrees LAO) and we advocate using the simple technique reported herein to define the renal origin in patients with pre-procedure MRA.
Factors influencing the need for target vessel revascularization after renal artery stenting.
PURPOSE: To provide additional insight into factors that may be associated with the need for target vessel revascularization (TVR) following de novo renal artery stenting during long-term follow-up. METHODS: A retrospective chart and database review was conducted to analyze the progress of all patients with de novo symptomatic renal artery stenosis who underwent stent-supported angioplasty under the auspices of the Single Operator, Single Center, Renal Stent Retrospective Study (SOCRATES). The records review identified 782 patients who were enrolled in the study between 1993 and 2004; after excluding 34 (4.5%) patients (lost to follow-up or inadequate data), 748 consecutive patients (412 women; mean age 70.7+/-9.7 years, range 37-92) were suitable for longitudinal analysis. The need for TVR was based on strict clinical criteria (> or =20% rise in serum creatinine, worsening hypertension, and/or recurrent flash pulmonary edema), and all patients underwent multidisciplinary evaluation before stenting and during follow-up. RESULTS: Follow-up spanned a mean 45.8+/-26.5 months. TVR was needed in 88 (10.03%) of 877 arteries and was best predicted by patient age < or =67 years (OR 2.91, p=0.0001), stent diameter < or =5.0 mm (OR 2.31, p=0.001), solitary functioning kidney (OR 2.01, p=0.048), history of lower extremity peripheral artery disease (OR 1.87, p=0.008), and antecedent history of stroke (OR 1.73, p=0.026). CONCLUSION: Renal artery stenting appears to be durable, with only 10% of stented arteries requiring TVR during clinically-based long-term follow-up. Arteries with a final stent diameter < or =5.0 mm were more than twice as likely to need TVR, as were patients with a solitary kidney. The authors acknowledge that clinical recurrence is not a surrogate for ultrasound surveillance after renal artery stenting, so prospective controlled trials will be needed to determine risk factors for restenosis.
Successful urgent endovascular surgery for symptomatic subclavian artery aneurysmal compression of the trachea.
The purpose of this study is to report the progress of a patient who entered the hospital with symptomatic tracheal compression from a large right subclavian artery aneurysm that was treated with a self-expanding stent graft. The patient was at increased risk for traditional surgery, thus endovascular isolation of the aneurysm was felt to be reasonable. A flexible self-expanding stent graft was placed via a brachial artery cutdown and common femoral access without complication. The symptoms improved and the patient remained asymptomatic at 2-year follow-up with serial CT scan confirmation of aneurysm regression. This unusual case illustrates that endovascular decompression of an aneurysm may have some benefit in alleviating subacute symptoms of extrinsic encroachment into other vital structures. Technical and clinical success was achieved with the stent graft deployment and this seems to be a reasonable alternative to surgery in such patients.
Fatal subclavian stent infection remote from implantation.
We report the unusual case of a 66-year-old alcoholic male who presented with acute arm ischemia 4 months following ipsilateral subclavian artery stenting. The patient had a petechial rash and Janeway lesions in the distribution of the affected subclavian artery. He had been treated for an infected dialysis graft 10 days prior to entry into the hospital. Subsequent angiogram confirmed a patent stent with intraluminal filling defects and occlusion of the brachial artery. Thrombectomy yielded material that was consistent with septic emboli and CT scan of the chest was suggestive of a mycotic aneurysm around the stent. The subclavian stent was removed surgically and the aneurysm was repaired. Unfortunately, the patient had multiple comorbidities and died of complications during recovery. This is the first case of a subclavian stent infection following septicemia remote from implantation.
Emergent stent graft isolation of a knife-related subclavian arterial venous fistula: lessons learned during long-term follow-up.
We present the unusual case of a 42-year-old gentleman who entered the trauma center with a hemothorax and intermittent bright red pulsatile blood from three stab wounds in the ipsilateral supraclavicular fossa. The patient was found on emergent angiography to have a large right subclavian artery to vein fistula that was treated successfully with a Dacron-covered stent. Angiography, 2 years following stent-graft isolation, confirmed a durable result with evidence of hemodynamically insignificant neointimal growth through the pores of the graft material. This case provides insight into the long-term effects of a Dacron-covered stent in patients with traumatic arterial injury. We discussed the advantages and disadvantages of different graft materials based on these angiographic findings.
Subclavian artery stenting: factors influencing long-term outcome.
This study provides extended follow-up of a nonrandomized series of symptomatic patients who underwent subclavian stent-supported angioplasty (SSA) with emphasis on preprocedure factors that may have influenced outcome. The endpoints of mortality and restenosis were analyzed using backward stepwise logistic regression with the following clinical variables: coronary artery disease, hypertension, hyperlipidemia, smoking, diabetes mellitus, chronic obstructive pulmonary disease, chronic renal insufficiency/failure, and hypothyroidism. Restenosis is reported based on prospective serial noninvasive studies and/or angiography. Mortality was evaluated by retrospective database review and inquiry to the State Department of Health and Human Services' statistical registry in patients who were lost to follow-up. Over a 9-year period (mean follow-up, 36.1 +/- 30.4 months; maximum observation, 109.5 months), 101 stents were placed in 91 consecutive patients (37 male, 54 female). The mean age at intervention was 62.03 +/- 9.3. The procedure was technically successful in 89 patients 97% (mean pre- and postoperative stenosis and pressure gradients were 90.2% +/- 9.4% vs. 3.7% +/- 6.6%, P < 0.001, and 59.9 +/- 35.2 vs. 0 mm Hg, P < 0.001, respectively), with 13 minor complications and no immediate major complications. One patient died of unrelated causes within 30 days. Per Kaplan-Meier method, for years 1 through 5, the rates of overall patency were 96%, 91%, 86%, 77%, and 72%; likewise, overall patient survival was 93%, 88%, 8%4, 81%, and 76%. No clear predictors for restenosis were discovered, although a trend toward higher recurrence was noted in women (18.5% in female vs. and 8.6% in male; P > 0.05), but the same were less likely to die during follow-up (P > 0.001). Also, the presence of hypothyroidism (P = 0.004) and increasing age (P = 0.068) were positively correlated with all-cause mortality. This study suggests that SSA is predictable, safe, and durable. The diagnosis of symptomatic subclavian disease is of prognostic importance, with age and male gender representing important predictors of all-cause long-term mortality. The strong association of increased mortality with hypothyroidism is difficult to discard and raises the question of a yet to be described thyroid steal phenomena.
High-output congestive heart failure successfully treated with transcatheter coil embolization of a large renal arteriovenous fistula.
Left heart catheterization was performed in response to progressive congestive heart failure of uncertain etiology in a 59-year-old male. The coronary arteries were normal but screening abdominal aortography revealed a large arterial venous communication between the left inferior segmental renal artery and the ipsilateral renal vein. The massive size and brisk flow patterns in the fistula presented technical challenges for transcatheter closure. The use of multiple Amplatz vascular obstructive devices (spiders) to create a matrix for securing subsequent coils in staged procedures and the patient's progress following successful closure are discussed.
Carotid stenting for symptomatic radiation-induced arteritis complicated by recurrent aneurysm formation.
We describe a 56-year-old male who underwent successful carotid stenting (CS) with adjuvant distal protection in response to symptomatic radiation-induced carotid disease. During the CS procedure, it was incidentally noted that the lesion yield pressure was surprisingly low (2 atm). The patient returned with local symptoms from common carotid aneurysmal dilation at the proximal edge of the stent that was successfully treated with a stent graft. A second aneurysm developed proximal to the stent graft and, based on intravascular ultrasound mapping, he ultimately underwent venous bypass covered by a free-muscle graft. We believe the low lesion yield pressure in this case reflected loss of vessel integrity and it may be prudent to avoid oversizing the stent in such patients.
An update on endovascular therapy of the lower extremities.
Considerable advances have been made over the last decade in percutaneous technology for treatment of atherosclerotic diseases in the iliac, femoropopliteal, and distal tibioperoneal arteries. While treatment strategies are well defined in the iliofemoral segment, where angioplasty and stenting perform well in appropriately selected lesions, the search for a durable transcatheter therapy for femoropopliteal and distal occlusive disease continues. The spectrum of treatment alternatives to angioplasty ranges from transcatheter plaque excision to laser ablation, rotational atherectomy, cryoplasty, brachytherapy, and stenting. We review in this article the status of percutaneous endovascular techniques for the treatment of lower extremity vascular occlusive disease.
Endovascular repair of abdominal aortic aneurysms using 3 commercially available devices: midterm results.
PURPOSE: To report the early and midterm results of 3 commercially available stent-grafts for abdominal aortic aneurysm (AAA) exclusion. METHODS: Since fall 1999, 151 patients (137 men; mean age 74 years, range 54-88) have undergone AAA repair using 88 Ancure, 46 AneuRx, and 17 Excluder stent-grafts in elective procedures. All patients were followed clinically and underwent postoperative duplex ultrasound and/or computed tomographic angiography, which was repeated every 6 months. RESULTS: The mean overall follow-up was 17 months (range 1-46). Initial technical failure was 3% (3/88) for Ancure versus 0% for AneuRx and Excluder. Primary endoleak occurred in 8% (7/88) of the Ancure patients versus 22% (10/46) for AneuRx and 6% (1/17) for Excluder (p=NS). Early (30-day) graft thrombosis (2/151, 1%) was seen only in the Ancure group. The perioperative complication rates (excluding endoleak and fever) were 22% (19/ 88) for Ancure, 15% (7/46) for AneuRx, and 0% for Excluder (p=NS). There was only 1 (0.7%) perioperative death in the series (Ancure patient). More ancillary procedures were performed in the Ancure group (p<0.05). Postoperatively, the size of the AAA decreased or remained unchanged in 76% for Ancure patients versus 75% for AneuRx and 64% for Excluder (p=NS). The incidences of late endoleak were 6% for Ancure, 2% for AneuRx, and 0% for Excluder (p=NS). The freedom from late endoleak at 3 years was 88% for Ancure and 97% for AneuRx (100% at 1 year for Excluder). Survival rates were similar. No AAA rupture was recorded. CONCLUSIONS: The Ancure device has slightly higher overall perioperative complications and early technical failure than AneuRx or Excluder. All 3 devices are effective in preventing aneurysm rupture; the overall midterm survival rates, freedom of endoleak, and limb patency are somewhat similar.
Reversal of the direction of internal carotid artery blood flow by occlusion of the common and external carotid arteries in a swine model.
In a swine model, blood flow direction [antegrade (+) and retrograde (-)] and velocity were defined within the common (CCA), internal (ICA), and external (ECA) carotid arteries during CCA occlusion with and without ECA occlusion and blood aspiration. In seven anesthetized swine, Doppler recordings of blood flow direction and velocity were performed in the CCA, ICA, and ECA, before and after vessel(s) occlusion, and after passively and actively induced reversal of blood flow direction. Baseline ICA and ECA blood flow direction and velocities were 92 +/- 4 and 90 +/- 3 cm/sec; and, with CCA occlusion, the ICA velocity decreased to 30 +/- 2 cm/sec (P < 0.001). No flow (zero velocity) occurred with CCA and ECA occlusion. An artificial femoral arteriovenous fistula's continuous gradient passively reversed ICA blood flow direction (-), with the recorded blood's velocity (-24 +/- 4 cm/sec) increasing with continuous active aspiration to -90 +/- 6 cm/sec. Occlusion of the CCA occlusion alone was unable completely to halt ICA antegrade blood flow direction, while CCA and ECA occlusion completely stopped ICA antegrade flow. CCA and ECA occlusion, when coupled with an arteriovenous fistula arteriovenous and/or aspiration, resulted in ICA blood flow direction reversal, whose velocity could be actively augmented.
Endovascular management of impending carotid rupture in a patient with advanced head and neck cancer.
PURPOSE: To describe an innovative endovascular technique combining a flexible self-expanding stent-graft to protect the common and internal carotid artery with selective coil embolization of the affected external carotid artery (ECA) branches. CASE REPORT: A 42-year-old man presented with episodes of profuse but self-limited carotid hemorrhage from advanced squamous cell carcinoma of the neck. Despite invasion of the carotid sheath by the tumor, angiography confirmed the source of bleeding to be invasion of branches of the ECA. Successful coil embolization of the ECA and stent-graft isolation of the common/internal carotid arteries were performed. At 1-month follow-up, carotid angiography confirmed the complete occlusion of the ECA and patent stent-graft. There was no recurrent bleeding or neurological deficits at 6 months after the procedure. CONCLUSIONS: Stent-grafts in combination with coil embolization can be used to manage patients with impending carotid rupture secondary to head and neck cancer.
Angioplasty/stenting of the superior mesenteric artery and celiac trunk: early and late outcomes.
PURPOSE: To analyze the early results and durability of angioplasty/stenting of the superior mesenteric artery (SMA) and celiac trunk (CT). METHODS: Twenty-two patients (19 women; mean age 69.2 years, range 52-88) with 24 symptomatic SMA or CT stenotic lesions were treated with dilation/stenting over a recent 4.5-year period. Two patients had lesions in both the SMA and CT treated. Clinical follow-up and duplex exams were done to evaluate long-term patency. Kaplan-Meier life-table analyses estimated the freedom from recurrent stenosis and recurrent symptoms, as well as survival rates. RESULTS: The initial technical and clinical success rates were 96% (23/24) and 95% (21/22), respectively, with no perioperative mortality or major morbidity. During a mean follow-up of 26 months (range 1-54), the primary late clinical success rate was 61% (11/18; 4 lost to follow-up), and freedom from recurrent stenosis (> or =70%) was 30% (6/20). The freedom from recurrent stenosis at 1, 2, 3, and 4 years were 65%, 47%, 39%, and 13%; freedom from recurrent symptoms was 67% at all 4 intervals. The survival rates were 93%, 93%, 80%, and 53% at 1 to 4 years, respectively. CONCLUSIONS: Angioplasty/stenting of SMA and CT stenoses has a high initial technical success rate and acceptable early and late clinical outcomes; however, it is associated with a high incidence of late restenosis based on strict Doppler criteria.
Successful treatment of iatrogenic renal artery perforation with an autologous vein-covered stent.
A 72-year-old woman developed severe flank pain associated with hemodynamic compromise immediately after a J-curve guidewire was inadvertently advanced into the right renal artery during cardiac catheterization. Contrast extravasation consistent with perforation of the main renal artery was seen on abdominal angiography. The perforation was successfully sealed using a premounted coronary stent that was covered with an autologous antecubital vein. Wide stent patency without aneurismal dilatation was confirmed on a 2-year follow-up renal angiogram.
Early postsurgical carotid restenosis: redo surgery versus angioplasty/stenting.
PURPOSE: To compare the results of balloon angioplasty/stenting (BA/S) versus redo surgery in patients with early carotid restenosis. METHODS: Sixty-one patients (35 women; mean age 69 years, range 46-82) with early restenosis (<24 months from the primary endarterectomy) in 63 carotid arteries were treated during a 5-year period; 41 patients (41 arteries) had redo surgery (group A) and 20 patients (22 arteries) had BA/S (group B). Patients were followed regularly with duplex ultrasound to detect >or=50% recurrent restenosis (RRS) after redo surgery or BA/S. Kaplan-Meier life-table analysis was used to estimate the stroke-free survival rates and freedom from >or=50% RRS. RESULTS: The demographic and clinical characteristics were comparable for both groups, as were the perioperative stroke and death rates (2.4% and 0% for group A, respectively, versus 4.5% and 0% for group B, p=0.46). Group A had a 12% incidence of cranial nerve injury (all transient) versus 0% for group B (p=0.11); however, group B had a higher incidence of >or=50% RRS than group A (32% versus 0%, p=0.0003). The stroke-free survival rates for redo surgery at 6, 12, 24, 36, and 48 months were 100%, 100%, 100%, 100%, and 88% versus 95%, 95%, 84%, 84%, and 63% for BA/S (p=0.067). Redo surgery had a 100% freedom from >or=50% RRS at the same time intervals, while recurrent restenosis rates for the BA/S patients were 95%, 86%, 69%, 52%, and 52% (p<0.0001). CONCLUSIONS: BA/S and redo surgery have comparable stroke and death rates in the treatment of early RCS; however, redo surgery is associated with cranial nerve injuries (transient), while stent patients have a higher incidence of recurrent lesions. These considerations should be kept in mind when selecting the appropriate treatment for patients with early postsurgical restenosis.