Comprehensive review of TIPS technical complications and how to avoid them.

OBJECTIVE: The goal of this article is to describe potential technical complications related to transjugular intrahepatic portosystemic shunts (TIPS) placement and to discuss strategies to avoid and manage complications if they arise. CONCLUSION: TIPS is an established interventional therapy for complications of portal hypertension. Although TIPS remains a relatively safe procedure, direct procedure-related morbidity rates are as high as 20%. The technical complexity of this intervention increases the risk for methodologic mishaps during all phases of TIPS placement, including venous access and imaging, transhepatic needle puncture, shunt insertion, and variceal embolization. Thus, interventional radiologists require a thorough stepwise understanding of TIPS insertion, possible adverse sequela, and technical tips and tricks to maximize the safety of this procedure.

Current tumor ablation technologies: basic science and device review.

Image-guided tumor ablation is an increasingly utilized tool to treat focal malignancy. Tumor ablation can be divided into two large categories, thermal and chemical ablation. The authors provide an overview of the current methods used to achieve thermal and chemical ablation of tumors, specifically addressing the basic science behind the ablation methods as well as providing a brief synopsis of the commercial devices currently available for use in the United States.

Laparoscopic transgastric access to the biliary tree after Roux-en-Y gastric bypass.

Gallstone disease, common after Roux-en-Y gastric bypass (RYGBP), may be complicated by biliary duct obstruction and gallstone pancreatitis. Although endoscopic retrograde cholangiopancreatography plays an important role in management of biliary duct obstruction, the altered anatomy of patients who have had a RYGBP makes this procedure technically difficult. With the increased number of patients undergoing RYGBP for morbid obesity, bariatric surgeons may benefit from an alternative laparoscopic technique for accessing the biliary tree. We describe a laparoscopic technique of accessing the biliary tree through the bypassed stomach.

External fixation in the treatment of tibial pilon fractures: comparison of two frames in torsion.

BACKGROUND: Ankle spanning external fixation has become the initial treatment of choice for complex tibial pilon fractures. Many fixator designs exist, but their biomechanical performance has not been studied extensively for this application. The goal of the present study was to compare the torsional performance of two commercially available frames, the Orthofix XCaliber and the Howmedica Hoffmann II. METHODS: The XCaliber and the Hoffmann II were each applied to six fresh cadaver lower extremities and were loaded in a materials testing machine. Strain gauges were attached to the anteromedial cortex of the distal tibia, and each specimen underwent torsional and axial load testing, with and without the external fixator. A simulated pilon fracture was created, and torsional testing was repeated. RESULTS: Results indicated that the XCaliber was significantly more rigid in internal rotation than the Hoffmann II, before (49%) and after (41%) creation of the pilon fracture. Despite the XCaliber's increased rigidity relative to the Hoffmann II (22% to 31%) in external rotation, statistical significance was not attained. Both fixators reduced strain (25% to 85%) at the anteromedial cortex upon torsional testing, but no significant differences between the two frames were noted. CONCLUSIONS: The present study demonstrates that the XCaliber has mechanical advantages over the Hoffmann II in terms of torsional rigidity for a tibial pilon fracture. CLINICAL RELEVANCE: Increased rigidity of the XCaliber could potentially lead to decreased time to union, and a lower incidence of pin loosening and would prove beneficial in a setting in which the external fixator is used as the definitive fixation.

Automated intraoperative EMG testing during percutaneous pedicle screw placement.

BACKGROUND: EMG screw testing has been shown to be sensitive and reliable in open spinal instrumentation cases. However, there is little evidence to show its applicability to percutaneous screw placement. PURPOSE: To demonstrate the utility of EMG testing in percutaneous techniques, where lack of direct visualization poses an added risk to nerve injury. STUDY DESIGN: Summary of intraoperative EMG results during percutaneous pedicle screw placement. METHODS: Percutaneous pedicle screws were placed in twenty patients (22 levels, 88 pedicles). The initial fluoroscopically-guided k-wires and the subsequent taps were insulated and stimulated via an automated EMG system. Low threshold values prompted repositioning of the pedicle trajectory. RESULTS: Four (5%) k-wires induced EMG thresholds less than 10mA, prompting repositioning. One was repositioned without improvement, but with improvement upon tapping. One k-wire with very low threshold (3mA) was repositioned with an improved result (13mA). In 78 pedicles (89%) the tap threshold was greater than the k-wire. CONCLUSIONS: EMG testing helps to identify suboptimal screw trajectories, allowing for early adjustment and confirmation of improved placement. Tapping often improved thresholds, perhaps by compressing the bone and creating a denser, more insulative pedicle wall. EMG testing may improve the safety of percutaneous screw techniques, where the pedicle cannot be visually inspected.

Renal ablation update.

Thermal ablative technologies have evolved considerably in the recent past and are now an important component of current clinical guidelines for the treatment of small renal masses. Both radiofrequency ablation and cryoablation have intermediate-term oncologic control that rivals surgical options, with favorable complication profiles. Studies comparing cryoablation and radiofrequency ablation show no significant difference in oncologic control or complication profile between the two modalities. Early data from small series with microwave ablation have shown similar promising results. Newer technologies including irreversible electroporation and high-intensity-focused ultrasound have theoretical advantages, but will require further research before becoming a routine part of the ablation armamentarium. The purpose of this review article is to discuss the current ablative technologies available, briefly review their mechanisms of action, discuss technical aspects of each, and provide current data supporting their use.

DVT surveillance program in the ICU: analysis of cost-effectiveness.

BACKGROUND: Venous Thrombo-embolism (VTE--Deep venous thrombosis (DVT) and/or pulmonary embolism (PE)--in traumatized patients causes significant morbidity and mortality. The current study evaluates the effectiveness of DVT surveillance in reducing PE, and performs a cost-effectiveness analysis. METHODS: All traumatized patients admitted to the adult ICU underwent twice weekly DVT surveillance by bilateral lower extremity venous Duplex examination (48-month surveillance period--SP). The rates of DVT and PE were recorded and compared to the rates observed in the 36-month pre-surveillance period (PSP). All patients in both periods received mechanical and pharmacologic prophylaxis unless contraindicated. Total costs--diagnostic, therapeutic and surveillance--for both periods were recorded and the incremental cost for each Quality Adjusted Life Year (QALY) gained was calculated. RESULTS: 4234 patients were eligible (PSP--1422 and SP--2812). Rate of DVT in SP (2.8%) was significantly higher than in PSP (1.3%) - p<0.05, and rate of PE in SP (0.7%) was significantly lower than that in PSP (1.5%) - p<0.05. Logistic regression demonstrated that surveillance was an independent predictor of increased DVT detection (OR: 2.53 - CI: 1.462-4.378) and decreased PE incidence (OR: 0.487 - CI: 0.262-0.904). The incremental cost was $509,091/life saved in the base case, translating to $29,102/QALY gained. A sensitivity analysis over four of the parameters used in the model indicated that the incremental cost ranged from $18,661 to $48,821/QALY gained. CONCLUSIONS: Surveillance of traumatized ICU patients increases DVT detection and reduces PE incidence. Costs in terms of QALY gained compares favorably with other interventions accepted by society.

Lack of liver uptake of 99mTc leukocyte scan in the setting of alcoholic steatohepatitis and dress syndrome.

We report an incidental finding of absent liver uptake of (99m)Tc leukocyte scan in an alcoholic patient with acute Zosyn (piperacillin and tazobactom)-related drug reaction with eosinophilia and systemic symptoms, persistent elevated white blood cell counts, and negative blood culture. Alcoholic steatohepatitis was confirmed in this patient through further clinical examination, blood test, and CT imaging.

Endovascular management of bleeding events following robotic pancreaticobiliary surgery.

PURPOSE: To describe the utility, safety, and efficacy of endovascular intervention for treating bleeding events after robotic pancreaticobiliary surgery. MATERIALS AND METHODS: In this retrospective study, six patients (male/female, 3/3; mean age, 64 years) with histories of robotic pancreaticobiliary resection were referred for endovascular management of delayed postoperative intra-abdominal hemorrhage. Visceral angiography was performed, and the sites of suspected arterial hemorrhage were interrogated with selective microcatheter arteriography. The visualized bleeding sources were treated using catheter-directed embolotherapy with metallic coils, bare metal or covered stent insertion, or a combination of the two. The measured outcomes included the technical success of the angiographic occlusion, procedure safety, and procedure efficacy. RESULTS: Pseudoaneurysms resulted in bleeding in six cases (100%). The endovascular interventions included coil embolization in three cases (50%), covered stent exclusion in two cases (33%), and bare metal stent-assisted coil embolization in one case (17%). The technical success was 100%, with complete cessation of bleeding in all cases. No immediate or delayed procedure-related complications were encountered in any of the patients. The efficacy of the endovascular therapy was 100% in this series, with no recurrent hemorrhage during the mean clinical follow-up period of 262 days (range, 67-446 days). CONCLUSION: Endovascular therapy provides a minimally invasive, safe, and effective method for managing hemorrhagic events after complicated pancreaticobiliary surgery.