Martin E. Simons

Efficacy of Embolization in Traumatic Uterine Vascular Malformations

PURPOSE To evaluate the efficacy of embolotherapy in patients with bleeding traumatic uterine arteriovenous malformations (AVMs). MATERIALS AND METHODS A retrospective review of all patients who underwent pelvic arterial embolization at our institution between July 1992 and September 2002 was performed. Fifteen patients were diagnosed with a uterine vascular malformation on duplex ultrasonography and correlative MR imaging. Serial beta-human chorionic gonadotropin levels were measured to exclude gestational trophoblastic neoplasia. All patients underwent transcatheter embolization of the uterine arteries. Embolizations were performed with use of standard 4-5-F catheters and microcatheters when necessary. Embolic agents in the 25 procedures included glue only (n = 13), polyvinyl alcohol (PVA) particles and glue (n = 4), PVA particles (n = 2), Gelfoam (n = 2), coils (n = 1), PVA particles and coils (n = 1), glue and Gelfoam (n = 1), and glue and coils (n = 1). PVA particle size ranged from 350 to 1,000 micro m. Outcomes assessed were cessation of bleeding, persistence or resolution of the AVM, complications, and pregnancy after embolization. These were assessed by chart, laboratory, and imaging reviews. RESULTS A total of 25 embolization procedures were performed in 15 patients. Six patients required repeat embolization (one patient underwent embolization on six occasions; five patients had two embolization procedures each) for recurrence of bleeding. Sixteen procedures were performed on an elective basis and nine were performed on an emergent basis. The technical success rate of embolization was 100%. The clinical success rate was 93%: bleeding was controlled in 14 of 15 patients and one patient underwent a hysterectomy. Four of the 15 patients subsequently had a total of five uneventful intrauterine pregnancies carried to term. The 14 patients who underwent successful embolization had no recurrence of bleeding at a median follow-up of 53 months (range, 3-124 months) after treatment. Three patients were eventually lost to follow-up. One minor complication (0.4%) of non-flow-limiting dissection of the internal iliac artery occurred. CONCLUSION Percutaneous embolotherapy is a safe and effective treatment for traumatic AVMs. This procedure allows for preservation of uterine function with the possibility of future pregnancy and should be considered as a primary treatment option.

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.

Percutaneous Management of Chronic Mesenteric Ischemia: Outcomes after Intervention

PURPOSE To assess the efficacy and durability of percutaneous transluminal angioplasty (PTA)/stent placement for treatment of chronic mesenteric ischemia (CMI). MATERIALS AND METHODS A retrospective review of patients treated from January 1986 to August 2003 was conducted. Twenty-nine patients (mean age, 62 years) were treated for clinical symptoms consistent with CMI. Clinical diagnosis was verified with angiographic assessment and PTA with or without stent placement was performed based on angiographic and/or pressure gradient findings. Outcomes were estimated with the Kaplan-Meier method. RESULTS A total of 63 interventions were performed in 29 patients during the study period. Of these 63 interventions, 46 PTA and 17 stent implantation procedures were performed. Thirty-four interventions were performed for SMA stenosis/occlusion, 17 interventions for celiac artery stenosis/occlusion, and four interventions were performed on aorto-mesenteric graft stenoses. Technical success was 97%, and clinical success (defined as clinical resolution of symptoms) was 90% (26 of 29 patients). Mean duration of follow-up was 28.3 months. Primary patency for all interventions at 3, 6, and 12 months was 82.7% (95% CI: 68.7-96.7), 78.9% (66.7-91.1), and 70.1% (55.1-85.6), respectively. Primary assisted patency for all interventions at 3, 6, and 12 months was 87.9% (79.0-95.3), 87.9% (79.2-95.1), and 87.9% (77.3-98.3), respectively. An average of 1.9 interventions per patient was required. One major complication occurred (3.4%). There were three minor complications (10.3%). CONCLUSIONS Percutaneous intervention for CMI is safe with durable early and midterm clinical success. However, repeated intervention is often required for improved primary assisted patency.

Arterial Embolization for Primary Postpartum Hemorrhage

PURPOSE To evaluate the efficacy and safety of arterial embolization (AE) for treatment of primary postpartum hemorrhage (PPH), and the factors associated with clinical success. MATERIAL AND METHODS A retrospective analysis of all patients undergoing AE for primary PPH at three institutions (N = 43) from 1996 through 2007 was conducted. Patients with an antepartum diagnosis of invasive placenta were excluded from the study. Mean patient age was 31 years +/- 5 (range, 21-40 y). Eighteen women (42%) were primiparous. Delivery details, transfusion requirements, hematology and coagulation results, embolization details, and clinical outcomes were collected. Clinical success was defined as cessation of bleeding without the need for repeat embolization, laparotomy, or hysterectomy after embolization; or death. The Fisher exact test was used to analyze nonparametric data. RESULTS The clinical success rate was 79% (n = 34). Four patients underwent successful repeat embolization. Two of 35 patients who had not undergone hysterectomy before embolization underwent hysterectomy for continued bleeding (without repeat embolization). One underwent hysterectomy 2 weeks after AE for uterine necrosis. One of eight patients who had undergone hysterectomy before AE required a laparotomy for a large retroperitoneal hematoma, and one patient died from cerebral anoxia secondary to hypotension despite repeat embolization. Clinical success was not related to mode of delivery, cause of PPH, transfusion requirements, time from delivery to embolization, or hysterectomy before AE (P > .05). Patients with active extravasation visualized angiographically were more likely to require repeat embolization (five of 13 [38%] vs 0 of 30 without extravasation; P < .01). CONCLUSIONS AE for primary PPH is safe and effective. Repeat embolization may be necessary in patients with active extravasation on angiography.

Procedural Success and Patency after Percutaneous Treatment of Thrombosed Autogenous Arteriovenous Dialysis Fistulas

PURPOSE To retrospectively evaluate success and midterm patency after percutaneous thrombectomy, lytic therapy, and angioplasty for thrombosed autogenous arteriovenous dialysis fistulas. MATERIALS AND METHODS From March 1996 to September 2001, 24 patients with 25 fistulas presented with 30 episodes of thrombosis of their autogenous fistulas, including 19 forearm radiocephalic fistulas in 18 patients and six upper arm brachiocephalic fistulas in six patients. Patients presented for percutaneous therapy within 48 hours of fistula thrombosis, with the exception of one patient who presented 7 days after thrombosis. Lytic therapy with urokinase or recombinant tissue plasminogen activator (rt-PA) was administered as a bolus into the fistula in 24 cases, with the exception of one case in which a 16-hour infusion of rt-PA was initiated. A mechanical thrombectomy device was used in a single case. Balloon thrombectomy was performed for residual clot. Angioplasty was performed at the arterial inflow, fistula, and outflow veins as required for identified areas of stenosis and/or maceration of thrombus. RESULTS Clinical success was achieved in 73% of cases (22 of 30). All patients were followed for a maximum of 66 months (mean, 12 mo). Primary patency rates were 36% at 3 months (95% CI, 18%-54%), 28% at 6 months (95% CI, 12%-46%), and 24% at 1 year (95% CI, 10%-42%). The assisted primary patency rate was 40% (95% CI, 21%-58%) at 3 months and stabilized at 32% at 6 months (95% CI, 15%-50%). The secondary patency rate stabilized at 3 months at 44% (95% CI, 24%-62%) for 15 months. Patency rates after clot removal were not significantly different between upper and lower arm fistulas (P =.14). Total observation time of the cohort of 25 fistulas was 296 months. The complication rate was 7% (two of 30), with one major complication and one minor complication. CONCLUSION Salvage of function after percutaneous clot removal from autogenous fistulas involves a steep learning curve initially and is possible with 3-month patency rates that approximate Kidney Disease Outcomes Quality Initiative recommendations for clot removal from polytetrafluoroethylene grafts.

A New Vascular Access Catheter for Hemodialysis

A new vascular access catheter has been developed (Cook Critical Care, Bloomington, IN) that is suitable for both short-term and long-term hemodialysis. Designed primarily for the internal jugular vein, it emerges through a subcutaneous tunnel on the anterior chest wall. With parallel cylindrical lumens to provide blood flows of 400 mL/min, it is compressible during insertion and can be placed percutaneously in the vein through a 13-French peel-away sheath. This allows repeated insertions at different times in the same patient. In 80 catheter insertions, we have found one case of jugular vein thrombosis attributable to the catheter and no subclavian vein thrombosis. After 15 months of use, the bloodstream infection rate was one per 19.7 patient-months. Using this device, it should be possible to stop the subclavian vein damage and perforating injuries that have been the most important complications of semistiff, tapered, subclavian catheters.

LGM (Vena Tech) Vena Cava Filter: Clinical Experience in 64 Patients

LG-Medical (LGM) vena cava filters were inserted percutaneously in 64 patients. Each case was followed after the filter insertion. Clinical follow-up was available in all patients; in 11 patients it was the only form of follow-up. Findings were available from autopsies in seven patients, plain abdominal radiographs in 42, and duplex sonograms of the insertion vein and inferior vena cava (IVC) in 46. A filter was inserted without major complication in all patients. The filter failed to open fully in four patients and was tilted in the IVC in 15. Recurrent pulmonary embolism was found in two patients (fatal in one), and inconsequential filter migration occurred in 11. Introduction vein thrombosis occurred in four patients. IVC thrombosis, demonstrated at autopsy or sonography, was found in 14 patients (22%) and was symptomatic in six (9%). This report suggests that the LGM filter is easy to introduce, and few complications are associated with insertion. The rate of caval thrombosis, however, may be higher than previously reported.

Risk of intrauterine infectious complications after uterine artery embolization.

PURPOSE To identify risk factors for the development of intrauterine infection following uterine artery embolization. MATERIALS AND METHODS A retrospective review of uterine artery embolizations (UAE) performed for the treatment of symptomatic fibroids from January 2000 to July 2003 was conducted. With logistic regression and the Fisher exact test, multiple variables were analyzed as predictors for intrauterine infectious complications requiring medical and/or surgical therapy, including the use of preprocedural antibiotics, embolic agent used, quantity of embolic material, location of fibroids (submucosal, nonsubmucosal), and size and location of the dominant fibroid. RESULTS A total of 414 UAE procedures were performed in 410 patients with a technical success rate of 99%. Average age of the patient cohort was 42.8 years (SD, 5.8 years). One hundred forty-eight patients (36.1%) had submucosal fibroids or fibroids projecting submucosally, 262 patients (63.9%) had nonsubmucosal fibroids. Intrauterine infectious complications requiring intravenous antibiotic therapy and/or surgery occurred in five patients (1.2%). A total of five infectious complications requiring therapy occurred in the submucosal group (3.4%) and none in the nonsubmucosal group. Patients within the submucosal group were more likely to develop intrauterine infectious complications than patients with nonsubmucosal fibroids based on univariate analysis (P = .006) but with logistic regression, the association was not significant (P = .079). No significant difference with embolic agent, quantity of embolic particles, use of preprocedure antibiotics, or size of or location of the dominant fibroid was found. CONCLUSION No specific risk factor for intrauterine infection following UAE was identified in this study. Infection after UAE is rare and appears to be a sporadic occurrence. Nevertheless, close surveillance is warranted in all women following UAE given the potential morbidity of this complication.

Superior Vena Cava Stenosis Associated With Hemodialysis Catheters

The cases are described of four patients on long-term hemodialysis who developed stenosis of the superior vena cava (SVC) that interfered with the functioning or placement of jugular catheters for hemodialysis. All four patients had previously received multiple subclavian and/or jugular catheters inserted for hemodialysis access. In three patients, the SVC stenosis was successfully dilated by balloon angioplasty, and in one of these a stent was inserted to prevent restenosis. These three patients have subsequently been successfully dialyzed with jugular catheters. Stenosis of the SVC should be suspected when jugular catheters in the SVC give inadequate flows in the absence of thrombotic obstruction. Balloon dilatation with or without vascular stenting may allow satisfactory vascular access to be reestablished.

Clinical failure after uterine artery embolization: evaluation of patient and MR imaging characteristics.

PURPOSE To investigate the patient and magnetic resonance (MR) imaging characteristics associated with clinical failure after uterine artery embolization (UAE). MATERIALS AND METHODS Seventy-eight consecutive patients who underwent UAE were examined. Contrast-enhanced MR imaging was performed before and 4 months after the procedure, and clinical follow-up was performed at 15 months. Patients were divided into success and failure groups strictly on the basis of their clinical outcomes. Clinical follow-up included evaluation of fibroid symptoms and the need for further treatment after UAE. Findings at pre- and postprocedural MR imaging were compared, and data collected included changes in uterine and fibroid volumes, fibroid location, and fibroid perfusion. RESULTS Fifty-eight patients were placed into the success group and 20 into the failure group. There were no differences between the baseline characteristics of the two groups. The reduction in uterine and dominant fibroid volumes was greater in the success group compared with the failure group; however, the difference was not statistically significant (success group: [295/845] 34.9% vs [80/282.5] 28.3%, respectively, P=.18; failure group: [317/733] 43.2% vs [114/337.6] 33.9%, P=.32). The reduction in total fibroid volume was greater in the success group than the failure group ([189.6/393.5] 48.2% vs [148.7/439.9] 33.8%, respectively; P=.02) despite the fact that the percentage of fibroids completely infarcted was similar between the two groups ([136/172] 79% vs [41/50] 82%, P=.77). Pedunculated subserosal fibroids were more common in the failure group than in the success group (P<.03) and did not reduce in volume as significantly (53.8% vs 14.7%, respectively; P=.02). CONCLUSIONS In general, the reduction in total fibroid volume after embolization is smaller in patients with poor clinical improvement. In addition, these patients have a higher number of pedunculated subserosal fibroids, and these fibroids tend to reduce in volume to a lesser extent.