S. William Stavropoulos

Renal angiomyolipoma: Long-term results after arterial embolization

PURPOSE Selective arterial embolization of renal angiomyolipomas (AMLs) was performed to prevent hemorrhage in patients with AMLs larger than 4 cm. This study was conducted to evaluate the long-term efficacy of AML embolization. MATERIALS AND METHODS Nineteen patients underwent embolization for 30 renal AMLs between July 1991 and June 2002. Of these, 10 patients had tuberous sclerosis (TS) with multiple AMLs and nine patients had a solitary sporadic AML. Embolization was performed with use of ethanol mixed with iodized oil (Ethiodol) in 29 tumors; coils were used in addition to the ethanol/Ethiodol mixture in one case. All tumors were completely embolized according to angiographic criteria including vascular stasis and absence of arterial feeders. The efficacy of embolization was determined over a mean follow-up period of 51.5 months (range, 6-132 months). Recurrence was defined as an increase in tumor size of greater than 2 cm on follow-up imaging and/or recurrent symptoms that required repeat embolization. An institutional review board exemption was obtained to perform this retrospective study. RESULTS Embolization of the renal AMLs was technically successful in all 19 patients and for all 30 lesions. AML recurrence was noted in 31.6% of patients (n = 19) and for 30% of lesions overall (n = 9). Six of 10 patients in the TS group had AML recurrences. No recurrences occurred in the patients with sporadic AML. In the TS group of 10 patients, there was a total of 21 AMLs and the overall tumor recurrence rate was 42.9% (nine of 21). Six lesions in four patients had to be reembolized because of recurrent symptoms, including one hemorrhage, and three lesions in two patients required repeat embolization because of a greater than 2 cm increase in size. The median time interval from embolization to recurrence was 78.7 months (range, 13-132 months). Statistical testing with use of the Fisher exact test demonstrated that patients with TS were significantly more likely to develop recurrence than those without TS (P = .01). CONCLUSIONS Transarterial embolization is effective in preventing hemorrhage in patients with renal AMLs. However, long-term follow-up revealed a high AML recurrence rate in patients with TS. Lifelong surveillance for recurrence after AML embolization is essential in patients with TS.

Experience with the recovery filter as a retrievable inferior vena cava filter.

PURPOSE This study evaluates clinical experience with the Recovery filter as a retrievable inferior vena cava (IVC) filter. MATERIALS AND METHODS One hundred seven Recovery filters were placed in 106 patients with an initial clinical indication for temporary caval filtration. Patients were followed up to assess filter efficacy, complications, eventual need for filter removal, time to retrieval, and ability to remove the filter. RESULTS The patient cohort consisted of 62 men and 44 women with a mean age of 48 years (range, 18-90 y). Mean implantation time was 165 days. Indications for filter placement in patients with deep vein thrombosis (DVT) and/or pulmonary embolism (PE) included contraindication to anticoagulation (n = 33), complications of anticoagulation (n = 8), poor cardiopulmonary reserve (n = 6), large clot burden (n = 3), and PE while receiving anticoagulation (n = 1). Indications for filter placement in patients without proven PE or DVT included immobility after trauma (n = 35); recent intracranial hemorrhage, neurosurgery, or brain tumor (n = 18); and other surgical or invasive procedure (n = 3). Three patients (2.8%) had symptomatic PE after placement of the Recovery filter. No caval thromboses were detected. No symptomatic filter migrations occurred. Recovery filter removal was attempted in 15 of 106 patients (14%) at a mean of 150 days after placement. The Recovery filter was successfully retrieved in 14 of 15 patients (93%); one removal was unsuccessful at 210 days after placement. Ninety-two filters (87%) currently remain in place. CONCLUSIONS Although all the filters were placed with the intention of being removed, a large percentage of filters were not retrieved. The Recovery filter was safe and effective in preventing PE when used as a retrievable IVC filter.

Prevalence and Treatment of Cephalic Arch Stenosis in Dysfunctional Autogenous Hemodialysis Fistulas

PURPOSE Cephalic arch stenosis (CAS) is a recently recognized cause of dysfunction in autogenous hemodialysis fistulas. The prevalence of this lesion among dysfunctional autogenous fistulas is described, as are outcomes after percutaneous therapy. MATERIALS AND METHODS A cohort of 177 dysfunctional autogenous fistulas treated over a 48-month period was retrospectively analyzed for the presence of CAS. Of these, 116 (66%) were radiocephalic fistulas and 61 (34%) were brachiocephalic fistulas. CAS was identified in 26 fistulas among 24 patients. Fifty dilations and three stent placements in the cephalic arch were performed. Surveillance was conducted after percutaneous therapy by means of ultrasound dilution technique and measurement of dialysis flow rates. Patency rates were estimated with use of the Kaplan-Meier method. No patients were lost to follow-up. RESULTS The prevalence of CAS was 15% (26 of 177). There was a significant difference in the prevalence of CAS between brachiocephalic and radiocephalic fistulas (39% vs 2%; P <.001). High-pressure noncompliant balloon catheters were required in 29 of 50 dilations (58%) to efface the lesion. Primary patency rates (+/-SE) at 3, 6, and 12 months were 76% +/- 8, 42% +/- 10, and 23% +/- 9, respectively. Primary assisted patency rates (+/-SE) at 3, 6, and 12 months were 96% +/- 4, 83% +/- 8, and 75% +/- 10. Complications occurred in three cases (6%). A major complication with rupture of the cephalic arch resulted in thrombosis and fistula loss (n = 1); two minor complications of cephalic arch rupture were salvaged with placement of a Wallstent (n = 1) or prolonged balloon inflation (n = 1). CONCLUSIONS CAS is common among failing brachiocephalic arteriovenous fistulas. With aggressive percutaneous intervention and surveillance, favorable primary assisted patency rates can be achieved.

Chemoembolization of colorectal liver metastases with cisplatin, doxorubicin, mitomycin C, ethiodol, and polyvinyl alcohol

Unresectable colorectal liver metastases have a 1‐ and 2‐year survival of 55% and 33% with current systemic therapies. The authors evaluated response and survival after transarterial chemoembolization.

Embedded Inferior Vena Cava Filter Removal: Use of Endobronchial Forceps

PURPOSE Removing a retrievable inferior vena cava (IVC) filter can be extremely difficult with the use of standard techniques if the filter is tilted and embedded in the wall of the IVC. The use of rigid endobronchial forceps has been described in case reports to remove embedded IVC filters, and the present report describes the use of this technique to remove a series of tip-embedded IVC filters in two separate institutions. MATERIALS AND METHODS The medical records were reviewed of 21 consecutive patients at two institutions who underwent attempted IVC filter removal with rigid endobronchial forceps over a 34-month period. The mean age of patients was 32.4 years (range, 14.1-54.1 y). The patients had the following filters: Recovery (n = 6), G2 (n = 10), Günther Tulip (n = 4), and OptEase (n = 1). RESULTS Rotational or biplane venography was used to confirm that the filters were tilted and embedded in the wall of the IVC in all 21 patients. Rigid endobronchial forceps were used successfully to remove 20 embedded IVC filters in 21 patients. There was one case of failure to remove an embedded suprarenal G2 filter. There were no major complications. CONCLUSIONS Rigid endobronchial forceps may be used as a reliable option for removal of embedded IVC filters.

Transplant renal artery stenosis: outcome after percutaneous intervention.

PURPOSE To assess the outcome of percutaneous transluminal angioplasty (PTA) and stent placement as the primary treatment for transplant renal artery stenosis (TRAS). MATERIALS AND METHODS A retrospective review of PTA and stent placement procedures performed for TRAS from April 1997 to July 2003 was conducted. Reviewed parameters included technical success, date of transplantation, dates of percutaneous intervention, mean arterial blood pressure, number of blood pressure medications, and serum creatinine level before and after intervention. Twenty-one interventions were performed in 18 allografts. The primary clinical indication for imaging and treatment was increased creatinine level in 12 allografts and hypertension in six allografts. Patency rates were estimated with use of the Kaplan-Meier method. RESULTS The technical success rate of PTA/stent placement was 100% and the clinical success rate was 94% (17 of 18 allografts). Thirteen interventions involved PTA alone, with eight combined PTA and stent insertions. The mean preintervention serum creatinine level among 12 allografts presenting with elevated creatinine levels was 2.8 mg/dL +/- 1.4 (SD), compared with a 1-month postintervention mean of 2.2 mg/dL +/- 0.7 (P = .03). Of six allografts that presented with hypertension, significant improvement was seen between the preintervention and 1-month postintervention mean systolic (174 mm Hg vs 135 mm Hg, P = .003) and diastolic (99 mm Hg vs 82 mm Hg, P = .02) pressures. These patients required a mean of 2.3 medications for blood pressure control before intervention, compared with a mean of 1.0 medications at 1 month after intervention (P = .002). Primary patency rates at 3, 6, and 12 months (+/-95% CI) were 94% +/- 6%, 72% +/- 12%, and 72% +/- 12%, respectively. Secondary patency rates at 3, 6, and 12 months (+/-95 CI) were 100%, 85% +/- 10%, and 85% +/- 10%, respectively. Mean follow-up time was 27 months. Of the eight allografts that underwent stent placement, all eight remained patent at last follow-up (mean, 18.3 months +/- 9.2). One major complication of a puncture site pseudoaneurysm occurred (5%). CONCLUSION Primary treatment of TRAS with PTA with or without stent placement has good intermediate-term patency and is associated with significant early improvement in blood pressure and creatinine level.

Relationship between Chest Port Catheter Tip Position and Port Malfunction after Interventional Radiologic Placement

PURPOSE The relationship between catheter tip position of implanted subcutaneous chest ports and subsequent port malfunction was investigated. Tip movement from initial supine position to subsequent erect position was also evaluated. MATERIALS AND METHODS Patients who underwent imaging-guided internal jugular chest port placement between July 2001 and May 2003 were identified with use of a quality-assurance database. Sixty-two patients were included in the study (22 men and 40 women), with a mean age of 58 years (range, 27-81 years). Catheter tip location on the intraprocedural chest radiograph was determined with use of two methods. First, the distance from the right tracheobronchial angle (TBA) was recorded (TBA distance). Second, tip location was classified into six anatomic regions: 1, internal jugular veins; 2, brachiocephalic veins; 3, superior vena cava (SVC; n = 11); 4, SVC/right atrial junction (n = 22); 5, upper half of right atrium (n = 25); and 6, lower half of right atrium (n = 4). For the duration of follow-up, catheter tip location was documented, as were all episodes of catheter malfunction. RESULTS Patients with catheter tips initially placed in position 3 had a higher risk of port malfunction (four of 11; 36%) than patients with catheter tips located in position 5 (two of 25; 8%). This difference narrowly fell short of statistical significance (P =.057). When comparing intraprocedural chest radiographs to the first erect chest radiographs, significant upward tip movement was noted. The tips migrated cephalad an average of 20 mm (P =.003) and 1.0 position units (P =.001). DISCUSSION Catheter tips placed in the SVC tended to have a greater risk of port malfunction compared with those positioned in the right atrium. Chest ports migrated cephalad between the supine and erect positions.

Type 2 endoleak embolization comparison: translumbar embolization versus modified transarterial embolization.

PURPOSE To evaluate the success of endoleak repair using translumbar (TL) endoleak embolization compared with a transarterial (TA) technique that involves embolization of the endoleak cavity itself in addition to the feeding artery. MATERIALS AND METHODS Eighty-four patients (mean age, 78.2 years; age range, 58-94 years) with type 2 endoleaks were included in this retrospective study. Patients underwent either TL endoleak embolization or TA embolization between January 2002 and December 2007. TA embolization involved entering the endoleak cavity through the inferior mesenteric or lumbar artery. Both the endoleak cavity and the feeding artery were then embolized by using coils through a microcatheter. TL embolizations were performed by using standard technique with coils and n-butyl cyanoacrylate as the embolization agents. Clinical success was defined as the absence of an endoleak and/or aneurysm enlargement at follow-up CT angiography. Statistical comparison was performed with the Fisher exact test. RESULTS Endoleak repair was successful in 72% (45/62) of the TL embolizations and 78% (18/23) of the TA embolizations, with a mean follow-up of 18.7 months (range, 1-84 months). There was no significant difference in clinical success between the two groups (P = .41). There were two (3.2%) complications in the TL group and no complications in the TA group. CONCLUSIONS The effectiveness of the TA endoleak embolization technique, which involves embolizion of the endoleak cavity and the feeding artery, is similar to that of TL embolization for treatment of type 2 endoleaks.

Percutaneous Transhepatic Venous Access for Hemodialysis

Percutaneous transhepatic venous access is an option for hemodialysis patients who have exhausted more traditional sites of venous access. Thirty-six transhepatic dialysis catheters were placed in 12 patients. The mean time of the catheters in situ was 24.3 days. Twenty-one catheters were replaced or removed because of catheter thrombosis, yielding a catheter thrombosis rate of 2.40 per 100 catheter-days. The line sepsis rate was 0.22 per 100 catheter-days. Poor patency rates were seen because of a high rate of late thrombosis. Transhepatic dialysis catheters should only be used as a last resort unless limitations of catheter thrombosis can be overcome.

Single-center Experience with the Arrow-Trerotola Percutaneous Thrombectomy Device in the Management of Thrombosed Native Dialysis Fistulas

PURPOSE The present study sought to evaluate the performance of the Arrow-Trerotola Percutaneous Thrombolytic Device (PTD) in the treatment of native fistula thrombosis in a U. S. hemodialysis population. Specifically, the technical success, clinical success, complication rate and type, primary and secondary patency rates, effect of adjunctive thrombolytic therapy, and any variables that affected outcomes of procedures in which this device was used were analyzed. MATERIALS AND METHODS Forty-two patients with 44 thrombosed native fistulas (17 radiocephalic, 10 brachiocephalic, 10 transposed or superficialized, five graft/fistula hybrids, and two leg fistulas) were treated with 62 mechanical thrombolysis procedures with use of the PTD. All patients had large clot burden. The device type was recorded in 43 procedures: standard (n = 21), over-the-wire (OTW; n = 19), or both (n = 3). No device was used in two cases because of inability to cross the anastomosis. Adjunctive therapies (n = 18) included the use of tissue plasminogen activator (tPA; n = 16) and deployment of the AngioJet device with (n = 1) or without tPA (n = 1). Stents were inserted in four procedures. Outcome variables included technical and clinical success, complications, and primary and secondary patency. Cox proportional-hazards regression and Kaplan-Meier analyses were performed. RESULTS The technical success rate was 87% (54 of 62) and the clinical success rate was 79% (49 of 62). Percutaneous transluminal angioplasty was performed in all but two procedures. Complications occurred in 13% of procedures (n = 8); three resulted in technical failure. The primary patency rates were 38% at 6 months and 18% at 12 months; secondary patency rates were 74% and 69%, respectively. Outcomes were not affected by adjunctive techniques, fistula type, age of fistula, device type (ie, OTW vs standard), or patient sex. Secondary patency was superior when no residual clot or stenosis was present (P = .003). CONCLUSIONS The PTD is effective for percutaneous treatment of thrombosed hemodialysis fistulas, with good short- and long-term outcomes in a U.S. population. Within the limitations of a retrospective study with a small sample size, use of an adjunctive thrombolytic agent did not appear to improve results compared with the use of the device alone.