Frequency of external iliac artery branch injury in blunt trauma: improved detection with selective external iliac angiography.

PURPOSE: To assess the utility of selective external iliac artery (EIA) angiography and the frequency of injury to branches of the EIA in cases of blunt pelvic trauma. MATERIALS AND METHODS: A retrospective review of pelvic angiograms in 66 patients with blunt pelvic trauma was conducted over a 12-month period. Pelvic and femur fracture patterns were correlated to the presence of EIA injury. Pelvic arteriography was compared versus selective EIA angiography for the detection of arterial injury. RESULTS: Fifty-four of 66 patients (82%) exhibited pelvic arterial injury or elicited enough suspicion for injury to warrant embolization. Internal iliac artery embolization was performed in 50 of 66 (76%). EIA branch injury was identified in 11 of 66 patients (17%), and 10 were successfully embolized. EIA branch vessel injury was identified more frequently when there was ipsilateral intertrochanteric fracture (P = .07) or ipsilateral ilium fracture (P = .07). The sensitivity of nonselective pelvic angiography in the detection of EIA branch vessel injury was 45%. CONCLUSIONS: EIA branch injury occurs in a substantial fraction of patients with blunt pelvic trauma who undergo pelvic angiography. Selective EIA angiography should be considered in all patients undergoing pelvic angiography in this situation.

Development of an intrabiliary MR imaging-monitored local agent delivery technique: a feasibility study in pigs.

PURPOSE: To investigate the feasibility of using magnetic resonance (MR) imaging to monitor intrabiliary delivery of motexafin gadolinium (MGd) into pig common bile duct (CBD) walls. MATERIALS AND METHODS: Animal studies were approved by the Institutional Animal Care and Use Committee. Initially, human cholangiocarcinoma cells were treated with various concentrations of MGd, a compound serving as a T1-weighted MR imaging contrast agent, chemotherapy drug, and cell marker. These cells were then examined by means of confocal microscopy to confirm the intracellular uptake of MGd. In addition, an MGd/trypan blue mixture was locally infused into CBD walls of six cadaveric pigs using a microporous balloon catheter. CBDs of six pigs were infused with saline to serve as controls. Ex vivo T1-weighted MR imaging of these CBDs was performed. For in vivo technical validation, the microporous balloon catheter was placed in the CBD by means of a transcholecytic access to deliver MGd/trypan blue into CBD walls of six living pigs. T1-weighted images were obtained with both a surface coil and an intrabiliary MR imaging guidewire, and contrast-to-noise ratios of CBD walls before and after MGd/trypan blue infusions were compared in the two groups by means of paired t test, with subsequent histologic analysis to confirm the penetration and distribution of the MGd/trypan blue agent into CBD walls. RESULTS: In vitro experiments confirmed uptake of MGd by human cholangiocarcinoma cells. The ex vivo experiments demonstrated the penetration of MGd/trypan blue into the CBD walls. The in vivo experiment confirmed the uptake of MGd/trypan blue, showing an increased contrast-to-noise ratio for the CBD after administration of the mixture, compared with images obtained prior to MGd/trypan blue administration (11.6 ± 4.2 [standard deviation] vs 5.7 ± 2.8; P = .04). Histologic results depicted the blue dye stains and red fluorescence of MGd in CBD walls, confirming the imaging findings. CONCLUSION: It is feasible to use MR imaging to monitor the penetration of locally delivered MGd into pig CBD walls.

Safety and efficacy of video-assisted retroperitoneal debridement for infected pancreatic collections: a multicenter, prospective, single-arm phase 2 study.

BACKGROUND: The feasibility of video-assisted retroperitoneal debridement (VARD) for infected pancreatic walled-off necrosis is established. We provide prospective data on the safety and efficacy of VARD. DESIGN: Multicenter, prospective, single-arm phase 2 study. SETTING: Six academic medical centers. PATIENTS: We evaluated 40 patients with pancreatic necrosis who had infection determined using Gram stain or culture. INTERVENTIONS: Percutaneous drains were placed at enrollment, and computed tomographic scans were repeated at 10 days. Patients who had more than a 75% reduction in collection size were treated with drains. Other patients were treated with VARD. Crossover to open surgery was performed for technical reasons and/or according to surgeon judgment. MAIN OUTCOME MEASURES: Efficacy (ie, successful VARD treatment without crossover to open surgery or death) and safety (based on mortality and complication rates). Patients received follow-up care for 6 months. RESULTS: We enrolled 40 patients (24 men and 16 women) during a 51-month period. Median age was 53 years (range, 32-82 years). Mean (SD) Acute Physiology and Chronic Health Evaluation II score at enrollment was 8.0 (5.1), and median computed tomography severity index score was 8. Of the 40 patients, 24 (60%) were treated with minimally invasive intervention (drains with or without VARD). Nine patients (23%) did not require surgery (drains only). For 31 surgical patients, VARD was possible in 60% of patients. Most patients (81%) required 1 operation. In-hospital 30-day mortality was 2.5% (intent-to-treat). Bleeding complications occurred in 7.5% of patients; enteric fistulas occurred in 17.5%. CONCLUSIONS: This prospective cohort study supports the safety and efficacy of VARD for infected pancreatic walled-off necrosis. Of the patients, 85% were eligible for a minimally invasive approach. We were able to use VARD in 60% of surgical patients. The low mortality and complication rates compare favorably with open debridement. An unexpected finding was that a reduction in collection size of 75% according to the results of computed tomographic scans at 10 to 14 days predicted the success of percutaneous drainage alone.

Steady-state free precession MRA of the renal arteries: breath-hold and navigator-gated techniques vs. CE-MRA.

PURPOSE: To explore the use of breath-hold and navigator-gated noncontrast Steady State Free Precession (SSFP) MR angiography (MRA) protocols for the evaluation of renal artery stenosis (RAS). MATERIALS AND METHODS: Twenty patients referred to rule out RAS were imaged using two breath-hold and one navigator-gated SSFP MRA sequences. All patients underwent contrast-enhanced MRA (CE-MRA). Two radiologists evaluated all sequences both qualitatively (blur, artifacts, reader confidence) and quantitatively (maximum stenosis). Using CE-MRA as truth, a receiver operating characteristics (ROC) curve was generated and a statistical analysis of navigator-gated SSFP (Nav SSFP) was performed. RESULTS: Seven patients had >50% renal artery stenosis by CE-MRA. Nav SSFP performed significantly better than either breath-hold SSFP technique in terms of blur, artifacts, and reader confidence. Using a 50% threshold for stenosis, sensitivity for detecting RAS was 100%, with a specificity of 85% and a negative predictive value of 100%. The average mean stenosis difference between Nav SSFP and CE-MRA was 9 +/- 9%. CONCLUSION: Nav SSFP outperformed breath-hold SSFP in measures of image quality and reader confidence. Sensitivity and negative predictive value for detecting RAS with Nav SSFP was perfect, with an acceptable specificity of 85%. This suggests further study is warranted to evaluate Nav SSFP as a noncontrast screening technique for renal artery stenosis.

Navigator-gated MR angiography of the renal arteries: a potential screening tool for renal artery stenosis.

OBJECTIVE: The purpose of our study was to determine how well unenhanced navigator-gated steady-state free precession (Nav SSFP) MR angiography (MRA) performs as a screening test for the detection of renal artery stenosis. SUBJECTS AND METHODS: Forty patients referred to rule out renal artery stenosis were imaged using an optimized Nav SSFP MRA sequence before conventional contrast-enhanced MRA (CE-MRA). Two radiologists evaluated Nav SSFP for maximum stenosis measurement, and comparison was made with CE-MRA results. RESULTS: Fifteen of the 40 patients had greater than 50% renal artery stenosis as determined on CE-MRA. Sensitivity for detecting renal artery stenosis with Nav SSFP was 100%; specificity, 84%; negative predictive value, 100%; and positive predictive value, 79%. The average mean stenosis difference between Nav SSFP and CE-MRA was 10% +/- 9%. CONCLUSION: Sensitivity and negative predictive value for the detection of renal artery stenosis using Nav SSFP were perfect, with an acceptable specificity of 84%. This suggests Nav SSFP is a promising technique for simple unenhanced screening for the detection of renal artery stenosis.

Cardiopulmonary consequences of transjugular intrahepatic portosystemic shunts: role of increased pulmonary artery pressure.

GOALS: To determine whether increased pulmonary artery pressure (PAP) following transjugular intrahepatic portosystemic shunting (TIPSS) results in short-term mortality or cardiorespiratory complications. BACKGROUND: TIPSS is frequently performed for complications of cirrhosis. PAP increases following TIPSS; however consequences of this phenomenon are unknown. STUDY: Demographics, disease severity and etiology were recorded among patients undergoing TIPSS. PAP before and following TIPSS were measured and the relationship between PAP before and after TIPSS, and subsequent cardiorespiratory complications and mortality was examined. RESULTS: Thirty-one patients were enrolled (mean age 53 years, 74% men, 55% Child-Pugh class C cirrhosis). TIPSS was performed for variceal bleeding in 84% of cases. Ten patients (32%) died 5-20 days following TIPSS. PAP increased significantly following TIPSS (mean 20.8 mm Hg pre-TIPSS (95% CI 18.2-23.4) to 26.9 mm Hg post-TIPSS (95% CI 24.2-29.6, P = 0.0016). Congestive heart failure developed in 4 patients (13%), sepsis in 4 (13%), and ARDS in 8 (26%). Increased PAP following TIPSS was not associated with early mortality (P = 0.13), CHF (P = 0.31), or ARDS (P = 0.43). ARDS was the only significant predictor of short-term mortality following TIPSS (OR 18.7, P = 0.02 (95% CI: 1.5-232). CONCLUSION: PAP increases after TIPSS and cardiorespiratory complications are common, yet unrelated to increased PAP. ARDS is independently associated with increased risk of mortality after TIPSS.