Keith M. Horton

Multicenter Trial of the Wallstent in the Iliac and Femoral Arteries

PURPOSE To report the results of the FDA phase II, multicenter trial of the Wallstent in the iliac and femoral arteries. PATIENTS AND METHODS Two hundred twenty-five patients entered the trial. Stents were placed in the iliac system in 140 patients and in the femoral system in 90 (five patients required both iliac and femoral stents). Clinical patency was measured over 2 years by means of life-table analysis with use of clinical and hemodynamic data and the Rutherford scale. Angiographic patency was measured at 6 months. RESULTS In the iliac system the primary clinical patency was 81% at 1 year and was 71% at 2 years. The secondary clinical patency was 91% and 86%, respectively. The 6-month angiographic patency was 93%. In the femoral system the primary clinical patency was 61% at 1 year and 49% at 2 years. The secondary patency was 84% and 72%, respectively. The 6-month angiographic patency was 80%. CONCLUSIONS The results are similar to those with the Palmaz stent in the iliac system and with angioplasty alone in the iliac and femoral systems.

Renal Artery Stent Placement for the Management of Ischemic Nephropathy

PURPOSE To evaluate the angiographic and clinical results of percutaneously implanted renal artery endoprostheses (stents) for the treatment of patients with ischemic nephropathy. MATERIALS AND METHODS During a 52-month period, 45 patients with azotemia (serum creatinine > or = 1.5 mg/dL) and atheromatous renal artery stenosis untreatable by, or recurrent after, balloon angioplasty were treated by percutaneous placement of Palmaz stents. Stent implantation was unilateral in 32 cases and bilateral in 11 cases. Clinical results were determined by measurements of serum creatinine and follow-up angiography. Clinical benefit was defined as stabilization or improvement in serum creatinine level. Angiographic patency was defined as less than 50% diameter recurrent arterial stenosis. RESULTS Stent placement was technically successful in 51 of 54 (94%) renal arteries. Technical failures were stent misdeployment requiring percutaneous stent retrieval (n = 2) and inadvertent placement distal to the desired position (n = 1). Complications included acute stent thrombosis (n = 1) and early initiation of hemodialysis (within 30 days; n = 1). There were two periprocedural deaths. With use of life-table analysis, clinical benefit was seen in 78% of patients at 6 months (n = 36), 72% at 1 year (n = 24), 62% at 2 years (n = 12), and 54% at 3 years (n = 3). In patients with clinical benefit, average creatinine level was reduced from 2.21 mg/dL +/- 0.91 before treatment to 2.05 mg/dL +/- 1.05 after treatment (P = .018). Lower initial serum creatinine level was associated with a better chance of clinical benefit (P = .05). No other variables affected outcome, including patient age, sex, diabetes, implanted stent diameter, unilateral versus bilateral stent placement, or ostial versus nonostial stent positioning. Conventional catheter angiography or spiral computed tomographic (CT) angiography performed in 19 patients (28 stents) at a mean interval of 12.5 months demonstrated primary patency in 75%. Maintained stent patency appeared to correlate with renal functional benefit. CONCLUSIONS Percutaneous renal artery stent placement for angioplasty failures or restenoses provides clinical benefit in most patients with ischemic nephropathy.

Treatment of Anastomotic Bypass Graft Stenosis with Directional Atherectomy: Short-term and Intermediate-term Results☆

PURPOSE Areas of anastomotic stenosis in lower-extremity bypass grafts (BPGs) were treated by means of directional atherectomy (DA) in hopes of achieving better patency rates than have been reported with percutaneous transluminal angioplasty (PTA). MATERIALS AND METHODS During a 4-year period, 17 patients (11 men and six women) with 23 areas of anastomotic stenosis in 18 lower-extremity BPGs were selected for treatment with DA. Urokinase thrombolysis was initially performed in eight BPGs that were thrombosed at the time of presentation. Adjunctive preatherectomy PTA was performed in six lesions, and postatherectomy PTA was performed in three lesions. RESULTS The technical success rate for DA was 92% (23 of 25 sites). There was less than 50% restenosis at 74% of the areas of stenosis (14 of 19 sites), with a mean follow-up time for the sites of 13 months. The graft patency rate was 88% (14 of 16 grafts), with a mean follow-up time for the grafts of 14 months. Areas of stenosis treated with DA alone had the same patency rates as those treated with DA and PTA. CONCLUSIONS DA is an effective treatment method for anastomotic peripheral arterial BPG stenosis. The intermediate-term patency rates following DA are superior to those reported for PTA and similar to those reported for surgical revision.

Phase I Results of Pullback Atherectomy for Hemodialysis Access

PURPOSE Balloon angioplasty and directional atherectomy frequently have short-lived results for stenoses associated with hemodialysis. Results are reported for a phase I trial of the pullback atherectomy catheter (PAC) for treatment of hemodialysis access-related stenoses. PATIENTS AND METHODS Six intragraft and six venous stenoses in nine patients were treated with the PAC. Two lesions were treated with adjunctive balloon angioplasty, and two were treated with adjunctive directional atherectomy. Clinical and angiographic follow-up were obtained for all patients. All specimens were examined histologically. RESULTS Initial procedural success was achieved in 83% of stenoses (10 of 12). For intragraft stenoses, the 6-month primary patency was 60% (three of five) and the 6-month secondary patency was 80% (four of five). All six venous stenoses restenosed or thrombosed within 3 months. All specimens contained fibrous plaque or intimal hyperplasia. In addition, all six venous stenosis specimens contained media and two contained adventitia. Significant complications during treatment of venous stenoses included severe venous spasm in three and venous pseudoaneurysms in two. One PAC tip fracture occurred during treatment of an intragraft stenosis. CONCLUSION Pullback atherectomy is potentially safe and effective for intragraft stenoses; however, it is not safe or effective for venous stenoses.

Fluoroscopically guided peritoneal catheter placement for intraperitoneal chemotherapy.

PURPOSE Surgical placement of intraperitoneal catheters for intraperitoneal chemotherapy is associated with bowel perforation, peritonitis, and catheter occlusion. The authors evaluated the safety and efficacy of fluoroscopically guided placement of temporary intraperitoneal catheters for chemotherapy. PATIENTS AND METHODS Two hundred one intraperitoneal catheter placements were attempted in 88 patients with peritoneal carcinomatosis or sarcomatosis. The peritoneum was punctured with 22-gauge needles and exchange was made with use of Seldinger technique and liberal injections of contrast material at each step for 8.3- or 8.5-F multiple-side-hole catheters. Placement sites included all four quadrants and the midline. Computed tomographic (CT) peritoneography was performed prior to chemotherapy. RESULTS One hundred ninety (94.5%) of 201 attempted catheter insertions were technically successful. Results of CT peritoneography were available in 175 cases and showed free distribution of peritoneal contrast material in 39% (n = 69), partial loculation in 38% (n = 67), and extensive loculation in 22% (n = 39). Catheters remained in place for a median of 5 days (range, 2-6 days). Significant complications occurred in 11 procedures (5.5%). There were seven unintended bowel intubations; all were treated conservatively except one that required surgical repair. One other patient developed necrotizing fasciitis requiring surgical débridement. Three other patients (1.5%) developed mild peritonitis responsive to antibiotics. Technical success, complications, and peritoneal distribution of contrast material did not correlate with the site of catheter placement. CONCLUSION Percutaneous catheter placement with use of small-gauge needles for initial puncture is safe and efficacious in patients requiring short-term peritoneal access for chemotherapy.

Percutaneous hepatic venous reanastomosis in a patient with Budd-Chaiari syndrome

A 33-year-old woman with Budd-Chiari syndrome for 9 years presented with worsening right upper quadrant pain and progressive liver dysfunction. Hepatic venography demonstrated hepatic vein occlusions, without significant IVC obstruction. Attempts at stenting a stenotic middle hepatic vein were unsuccessful. Transjugular access, however, allowed puncture from the stump of the right hepatic vein into the engorged right intrahepatic vein that had been demonstrated by retrograde hepatic venography. Two Palmaz stents were used to form the veno-venous reanastomosis. Initial success was documented angiographically and by pressure measurements before and after shunting. Followup at 7 and 16 months confirmed patency of the anastomosis without intimai hyperplasia. The patient noted near-complete resolution of her pain, and her liver function stabilized.

Ergonomic Vascular Access Needle with Blood-Containment Capability: Clinical Evaluation during Arterial Access Procedures

PURPOSE To evaluate the performance of the ergonomic vascular access needle (EVAN), which is designed to contain blood while allowing for observation of pulsations before passage of a guide wire, in arterial catheterization. MATERIALS AND METHODS EVANs were used for initial puncture in 118 arterial access procedures. Visualization of pulsatile blood motion and containment of blood were prospectively evaluated. Results from 82 separate procedures performed with standard access needles were used as a control. Success or failure of guide-wire passage through the needle, number of attempts, guide-wire type, findings on the access vessel arteriogram, and complications were recorded for both groups. RESULTS In the EVAN group, 92% of procedures were successfully completed, usually within two attempts (82%). Success was independent of guide-wire type (P = .4) and was not significantly different from that of the control group (96%) (P = .37). In 89% of the EVAN procedures, contained pulsatile blood motion was observed before attempted guide-wire passage. Uncontrolled spraying of pulsatile blood did not occur unless the hemostasis valve was removed. In 16%, slow oozing of blood occurred through the needle hub, mainly during guide-wire passage. Oozing was common with floppy-tipped guide wires (46%) but was uncommon with stiffer-tipped wires (6%). There were no needle-related complications. CONCLUSION The EVAN provides protection from blood spray while allowing for successful guide-wire passage into the arterial system as often as standard access needles. However, slow periwire leakage occurs frequently with floppy-tipped guide wires.