Andrew H. Stockland

Effect of suprarenal versus infrarenal aortic endograft fixation on renal function and renal artery patency: a comparative study with intermediate follow-up ☆

PURPOSE Suprarenal fixation of aortic endografts appears to be a safe option in patients with a short or conical proximal aortic neck. However, concern persists regarding the long-term effect on renal function when renal artery ostia are crossed by the uncovered stent. We investigated the effect of suprarenal versus infrarenal endograft fixation on renal function and renal artery patency after endovascular aortic aneurysm repair. METHODS Records of 91 patients who underwent endovascular aortic aneurysm repair with a modular bifurcated stent graft between November 1999 and January 2002 were reviewed retrospectively. Two patients receiving dialysis because of chronic renal failure were excluded. Infrarenal fixation was used in 57 patients (group 1), and suprarenal fixation was used in 32 patients (group 2). In two patients in group 1 a Gianturco Z stent was inserted transrenally because of intraoperative proximal type I endoleak, and data for these patients were excluded from analysis. Follow-up evaluation was performed at 1, 6, and 12 months, and yearly thereafter, and included clinical assessment, measurement of serum creatinine concentration (SCr), and computed tomography angiography, per standard protocol. Median follow-up was 12 months (range, 1-36 months). RESULTS There was no statistically significant difference in patient demographic data, aneurysm size, or preoperative risk factors. Median SCr was significantly higher in group 2 (suprarenal fixation) than in group 1 (infrarenal fixation) preoperatively (1.2 mg/dL [range, 0.6-2.3 mg/dL] vs 0.9 mg/dL [range, 0.6-1.9 mg/dL], P =.008) and at 1 month postoperatively (1.1 mg/dL [range, 0.8-5.6 mg/dL] vs 1.0 mg/dL [range, 0.6-2.1 mg/dL], P =.045). There was a significant increase in median SCr in both groups at 1 month postoperatively (group 1, 1.0 mg/dL [range, 0.6-2.1 mg/dL], P =.05; group 2, 1.1 mg/dL [range, 0.8-5.6 mg/dL] [mean SCr, 1.35 mg/dL vs 1.15 mg/dL, respectively], P <.05). In group 1 SCr was increased significantly at 6 and 12 months (P <.001), whereas in group 2 SCr also increased at 6 and 12 months, but not significantly. The change in SCr over time was not significantly different between the two groups. In two of 32 patients in group 2, renal artery occlusion developed, associated with perfusion defects in renal parenchyma and persistently elevated SCr. Analysis of renal artery patency did not demonstrate any association between patency and treatment. No patient developed hypertension during follow-up. CONCLUSIONS Suprarenal endograft fixation does not lead to significant renal dysfunction, and renal artery occlusion is uncommon within 12 months. A larger study with longer follow-up is essential to determine overall effects on renal function and renal artery patency.

Association between prior peripherally inserted central catheters and lack of functioning arteriovenous fistulas: a case-control study in hemodialysis patients.

BACKGROUND Although an arteriovenous fistula (AVF) is the hemodialysis access of choice, its prevalence continues to be lower than recommended in the United States. We assessed the association between past peripherally inserted central catheters (PICCs) and lack of functioning AVFs. STUDY DESIGN Case-control study. PARTICIPANTS & SETTING Prevalent hemodialysis population in 7 Mayo Clinic outpatient hemodialysis units. Cases were without functioning AVFs and controls were with functioning AVFs on January 31, 2011. PREDICTORS History of PICCs. OUTCOMES Lack of functioning AVFs. RESULTS On January 31, 2011, a total of 425 patients were receiving maintenance hemodialysis, of whom 282 were included in this study. Of these, 120 (42.5%; cases) were dialyzing through a tunneled dialysis catheter or synthetic arteriovenous graft and 162 (57.5%; controls) had a functioning AVF. PICC use was evaluated in both groups and identified in 30% of hemodialysis patients, with 54% of these placed after dialysis therapy initiation. Cases were more likely to be women (52.5% vs 33.3% in the control group; P = 0.001), with smaller mean vein (4.9 vs 5.8 mm; P < 0.001) and artery diameters (4.6 vs 4.9 mm; P = 0.01) than controls. A PICC was identified in 53 (44.2%) cases, but only 32 (19.7%) controls (P < 0.001). We found a strong and independent association between PICC use and lack of a functioning AVF (OR, 3.2; 95% CI, 1.9-5.5; P < 0.001). This association persisted after adjustment for confounders, including upper-extremity vein and artery diameters, sex, and history of central venous catheter (OR, 2.8; 95% CI, 1.5-5.5; P = 0.002). LIMITATIONS Retrospective study, participants mostly white. CONCLUSION PICCs are commonly placed in patients with end-stage renal disease and are a strong independent risk factor for lack of functioning AVFs.

Percutaneous Cryoablation of Stage T1b Renal Cell Carcinoma: Technique Considerations, Safety, and Local Tumor Control

PURPOSE To describe the technical methods, safety, and local tumor control rate associated with percutaneous cryoablation of stage T1b renal cell carcinoma (RCC). MATERIALS AND METHODS A retrospective review of a percutaneous renal ablation registry was used to identify 46 patients with a total of 46 biopsy-proven RCC lesions measuring 4.1-7.0 cm treated with cryoablation between 2003 and 2011. The main outcome parameters investigated were adjunctive maneuvers, complications, and local tumor progression, and cancer-specific survival rates. Complication rates were categorized and recorded using the Clavien-Dindo classification system. Progression-free and cancer-specific survival rates were estimated using the Kaplan-Meier method. RESULTS The mean treated RCC size was 4.8 cm (range, 4.1-6.4 cm). Prophylactic tumor embolization was performed in 7 patients (15%), ipsilateral ureteral stents were placed in 7 patients (15%), and hydrodisplacement of bowel was performed in the treatment of 16 tumors (35%). A single technical failure (2.2%) was observed at the time of ablation. Thirty-six tumors (78%) had follow-up imaging at 3 months or later following ablation, including a single recurrence at 9 months after ablation. The mean duration of follow-up for the 35 RCC tumors that did not recur was 2.0 years (range, 0.3-6.1 y). Estimated local progression-free survival rate at 3 years was 96.4%. Of the 46 cryoablation procedures, there were 7 complications (15.2%) of grade II or worse. CONCLUSIONS The results suggest that cryoablation represents a valid treatment alternative for select patients with clinical stage T1b RCC. Complications are frequent enough that multidisciplinary patient management should be considered.

Pneumomediastinum following Enteryx injection for the treatment of gastroesophageal reflux disease.

We describe the case of a 68-year-old female who developed pneumomediastinum following the “Enteryx” procedure for the treatment of gastroesophageal reflux disease (GERD). The patient required hospitalization and parenteral antibiotics and responded favorably to a conservative approach. Similar complications have been observed with other endoscopic treatment modalities for GERD such as Stretta and suturing techniques. Our patient represents the third reported case of a serious complication after Enteryx implantation.

The Timing and Presentation of Major Hemorrhage After 18,947 Image-Guided Percutaneous Biopsies

OBJECTIVE The objective of our study was to characterize the temporal and clinical manifestation of major bleeding events after biopsy to guide clinicians in the institution of appropriate surveillance. MATERIALS AND METHODS We performed a retrospective review of percutaneous image-guided biopsies performed between September 1, 2005, and May 31, 2012, including 18,947 biopsy events. According to routine protocol, follow-up telephone calls were made to patients 24 hours after biopsy, and chart review was performed 3 months after biopsy. Bleeding complications were defined using the Common Terminology Criteria for Adverse Events (CTCAE, version 4.0) established by the National Cancer Institute. In patients with a grade 3 or greater bleeding complication, a retrospective chart review was performed to characterize the details of the complication including the timing of the complication and the primary clinical presentation of the event. RESULTS Grade 3 hemorrhage was associated with 64 of 18,947 (0.3%) procedures, and there were three deaths associated with the biopsy event (0.02% or ≈ 2/10,000). Hemorrhage was most commonly associated with biopsy of a native kidney (17/1407, 1.2%). Twenty patients (31%) presented with a bleeding complication within 1 hour of biopsy. Twenty-seven patients (42%) presented within 2 hours of biopsy. Fifty-two patients (81%) presented within 24 hours, and the remaining 12 patients (19%) presented more than 24 hours after biopsy. Pain was the most common presentation of patients with bleeding complications, occurring in 39 (61%) patients. CONCLUSION The incidence of major bleeding after percutaneous biopsies is very low, but delayed complications occur more frequently than anticipated. Pain is the most common clinical presentation of major bleeding complications.

Lumbar artery pseudoaneurysm caused by a Gunther Tulip inferior vena cava filter.

Inferior vena cava (IVC) filters are widely used to decrease the risk of pulmonary embolism in patients with contraindications to anticoagulation. Complications include local hematoma, access site deep venous thrombosis (DVT), filter migration and embolization, leg penetration through the IVC wall, IVC occlusion, and filter fracture with embolization. Other rare complications include leg penetration into adjacent organs including duodenum and ureter. Lumbar artery pseudoaneurysms are rare and may be spontaneous, iatrogenic, or traumatic. To date, there have been 3 case reports of lumbar artery pseudoaneurysms caused by IVC filters. We present an additional case of a lumbar artery pseudoaneurysm caused by a Gunther Tulip IVC filter treated successfully with selective embolization.

Percutaneous Protective Coil Occlusion of the Proximal Inferior Mesenteric Artery before N-Butyl Cyanoacrylate Embolization of Type II Endoleaks after Endovascular Repair of Abdominal Aortic Aneurysms

Bowel ischemia can complicate treatment of type II endoleak with liquid or semiliquid agents such as n-butyl cyanoacrylate (NBCA) if nontarget embolization of the inferior mesenteric artery (IMA) occurs. The current report describes four cases of type II endoleak in which the IMA was the main outflow vessel and was prophylactically occluded with embolization coils before NBCA injection into the endoleak nidus. The purpose was to prevent unintentional embolization of the NBCA into IMA branches. If feasible, protective IMA coil occlusion should be considered in type II endoleaks with IMA outflow in cases of NBCA embolization.

Tube Thoracostomy: A Review for the Interventional Radiologist

Small-caliber tube thoracostomy is a valuable treatment for various pathologic conditions of the pleural space. Smaller caliber tubes placed under image guidance are becoming increasingly useful in numerous situations, are less painful than larger surgical tubes, and provide more accurate positioning when compared with tubes placed without image guidance. Basic anatomy and physiology of the pleural space, indications, and contraindications of small caliber tube thoracostomy, techniques for image-guided placement, complications and management of tube thoracostomy, and fundamental principles of pleurodesis are discussed in this review.

A Comparison of AneuRx Aortic Cuff and Zenith Distal Flare Exclusion of Common Iliac Artery Ectasia for Endovascular Aneurysm Repair

Stent-grafts are ideally terminated within the common iliac artery (CIA). However, CIA ectasia may require hypogastric artery occlusion, with stent-graft extension to the external iliac artery. Alternatively, the diameter of the distal stent-graft may be increased, or flared, to allow exclusion of the abdominal aortic aneurysm. This report details the authors’ experience with this technique. Forty-one patients received bifurcated stent-grafts (BSG): 20 received an AneuRx device, and 21 received a Zenith device. CIA ectasia (diameter 15–25 mm) was treated with a distal flare of 2–4 mm greater than the CIA diameter. Patients were followed up with computed tomography scan at 1, 6, and 12 months. Statistical analysis was performed using ANOVA within groups and unpaired two-tailed t test between groups. A p value of <0.05 was considered significant. Eight of 20 patients (40%) (11 CIA) received an AneuRx device and 13/21 (62%) (17 CIA) received a Zenith device, with a distal flare. Values are (n) mean (mm) ± SE. There were no deaths, endoleaks, migrations, or conversions to open repair. Follow-up mean was 24.7 and 20.6 (range 15–28) months for AneuRx and Zenith groups, respectively. In comparing initial and 12-month CIA diameters, AneuRx grafts 20 ±0.8 vs 21.5 ±1.0 were not significantly different, p= 0.2, nor was the same comparison for Zenith, 17 ±0.5 vs 19.1 ±0.4, significant, p= 0.57. At a mean follow-up of 12 months, distal flare of iliac limbs with either AneuRx or Zenith devices affords a seal for CIA ectasia and/or aneurysms complicating EVAR.

Use of proximal aortic cuffs as an adjunctive procedure during endovascular aortic aneurysm repair

The purpose of this study was to evaluate the incidence and durability of additional proximal cuffs during endovascular abdominal aortic aneurysm repair (EVAR). A retrospective review of 90 EVAR patients was conducted. Postoperative survival, proximal sealing zone–related complications, and secondary procedures were analyzed. Additional proximal cuffs were used in 11%. Their use did not affect postoperative survival (p = .58), type I endoleak rate (4.4%; p = .19), or the need for sealing zone–related secondary procedures (6.3%; p = .38) compared with patients without cuff placement but was related to a higher cumulative graft migration rate (2.2% overall p = .02). Two patients (2.5%; p = .79) underwent conversion to open surgery, both for proximal sealing zone–related complications. Application of proximal cuffs appears to be an effective intraoperative adjunctive procedure to achieve a proximal seal during EVAR, with favorable midterm results. However, the risk of late endograft migrations may be elevated in this group.