Howard M. Richard

Correlation of Multidetector CT Findings with Splenic Arteriography and Surgery: Prospective Study in 392 Patients

BACKGROUND To determine the accuracy of contrast-enhanced multidetector CT (MDCT) in demonstrating splenic vascular injury based on results of splenic angiography and operation. STUDY DESIGN This institutional review board-approved study included 392 hemodynamically stable blunt trauma patients whose admission MDCTs demonstrated splenic injury. Images were assessed for parenchymal injury grade, hemoperitoneum volume, and evidence of bleeding and nonbleeding splenic vascular injury. Splenic arteriography was performed for high splenic injury grade and splenic vascular injury. Medical records were reviewed to determine arteriographic interpretation, surgery indications and findings, outcomes, and demographics. Sensitivity, specificity, predictive values, and accuracy of MDCT in detecting vascular injury were calculated based on results of arteriography and operation. RESULTS Splenic vascular injury was seen in 22% of patients (86 of 392) on MDCT. Presence of a vascular injury correlated with the CT-based parenchymal splenic injury grade (p < 0.0001). Active splenic bleeding was associated with subsequent clinical deterioration (p < 0.0001). Overall, MDCT had a sensitivity of 76% (76 of 100); specificity of 90% (95 of 106); negative and positive predictive values of 80% (95 of 119) and 87% (76 of 87), respectively; and accuracy of 83% (171 of 206) in detecting vascular injury compared with reference standards. The success rate of nonoperative management was 96%. CONCLUSIONS MDCT provides valuable information to direct initial clinical management of patients with blunt splenic trauma by demonstrating both active bleeding and nonbleeding vascular injuries. Not all vascular injuries are detected on MDCT, and splenic angiography is still indicated for high-grade parenchymal injury.

A Randomized, Prospective Evaluation of the Tesio, Ash Split, and Opti-flow Hemodialysis Catheters

PURPOSE A randomized, prospective evaluation of three high-flow hemodialysis catheters. MATERIALS AND METHODS Ninety-four patients were randomly assigned 113 Tesio, Ash split, and Opti-flow catheters from December 1998 through June 1999. Insertion times, procedural complications, and ease of insertion were recorded. Mean catheter flow rates were recorded at first dialysis, 30 days, and 90 days. Patency, catheter survival, and catheter-related infections were evaluated. RESULTS Thirty-eight Ash split, 39 Opti-flow, and 36 Tesio catheters were placed. Tesio mean insertion time (41.5 min) was significantly longer than Ash split (29.4 min) or Opti-flow (29.6 min) (P =.004). There were four complications related to Tesio catheters (three cases of pericatheter bleeding, one air embolism), one related to an Opti-flow catheter (pericatheter bleeding), and zero related to Ash split catheters. Opti-flow and Ash split catheters were significantly easier to insert than Tesio catheters (P =.041). Mean flow rates were not significantly different among the catheters initially (P =.112), at 30 days (P =.281), or at 90 days (P =.112). Catheter-related infection rates per 100 catheter days were 0.12 for Ash split, 0.35 for Opti-flow, and 0.14 for TESIO: Median catheter survival was 302 days for Ash split, 176 days for Opti-flow, and 228 days for TESIO: CONCLUSIONS Opti-Flow and Ash split catheters were faster and easier to place than Tesio catheters. There was no difference in hemodialysis flow rates or catheter survival.

Towards a teleoperated needle driver robot with haptic feedback for RFA of breast tumors under continuous MRI

OBJECTIVE The purpose of this paper is to explore the feasibility of developing a MRI-compatible needle driver system for radiofrequency ablation (RFA) of breast tumors under continuous MRI imaging while being teleoperated by a haptic feedback device from outside the scanning room. The developed needle driver prototype was designed and tested for both tumor targeting capability as well as RFA. METHODS The single degree-of-freedom (DOF) prototype was interfaced with a PHANToM haptic device controlled from outside the scanning room. Experiments were performed to demonstrate MRI-compatibility and position control accuracy with hydraulic actuation, along with an experiment to determine the PHANToMs ability to guide the RFA tool to a tumor nodule within a phantom breast tissue model while continuously imaging within the MRI and receiving force feedback from the RFA tool. RESULTS Hydraulic actuation is shown to be a feasible actuation technique for operation in an MRI environment. The design is MRI-compatible in all aspects except for force sensing in the directions perpendicular to the direction of motion. Experiments confirm that the user is able to detect healthy vs. cancerous tissue in a phantom model when provided with both visual (imaging) feedback and haptic feedback. CONCLUSION The teleoperated 1-DOF needle driver system presented in this paper demonstrates the feasibility of implementing a MRI-compatible robot for RFA of breast tumors with haptic feedback capability.

Percutaneous Transrenal Hemodialysis Catheter Insertion

During the course of providing adequate access for hemodialysis, the majority of patients with end-stage renal disease will encounter episodes of catheter dependency. Although catheter-based dialysis is inferior to that obtained through native or synthetic arteriovenous conduits, it is often the only way to provide durable venous access into the central venous circulation system for large volume exchanges. Traditional sites for venous access such as internal/external, subclavian, and common femoral veins will eventually occlude. When alternative percutaneous access sites such as translumbar, transhepatic, and transazygous fail or become less desirable, other approaches become necessary. The authors report a successful case of transrenal access into the renal vein with consequent insertion of a tunneled catheter for hemodialysis in a patient with limited options.

Torsion of the fallopian tube: progression of sonographic features.

Isolated torsion of the fallopian tube is a rare gynecologic condition that is difficult to diagnose preoperatively. We present the sonographic and CT findings over a 48‐hour period in a case of isolated torsion of the fallopian tube. The radiologic features of isolated torsion have been described previously; however, to our knowledge, the progressive findings have not been previously reported.

Design, development, and evaluation of a master-slave surgical system for breast biopsy under continuous MRI

Magnetic Resonance Imaging (MRI) provides superior soft-tissue contrast in cancer diagnosis compared to other imaging modalities. However, the strong magnetic field inside the MRI bore along with limited scanner bore size poses significant challenges. Since current approaches in breast biopsy using MR images are primarily blind targeting approaches, it is necessary to develop an MRI-compatible robot that can avoid multiple needle insertions into the breast tissue. This MRI-compatible robotic system could potentially lead to improvement in the targeting accuracy and reduce sampling errors. A master–slave surgical system has been developed comprising a MRI-compatible slave robot which consists of one piezo motor and five pneumatic cylinders connected by long pneumatic transmission lines. The slave robot follows the configuration of the master robot, which provides an intuitive manipulation interface for the physician and operates inside the MRI bore to adjust the needle position and orientation and perform needle insertion tasks. Based on the MRI experiments using the slave robot, there was no significant distortion in the images, and hence the slave robot can be safely operated inside the MRI with minimal loss in signal-to-noise ratio (SNR). Ex vivo and in vivo experiments have been conducted to evaluate the performance of the master–slave surgical system.

Evaluation of the Amplatzer Vascular Plug for Proximal Splenic Artery Embolization

PURPOSE Proximal splenic artery embolization is performed for splenic salvage in the setting of trauma or before splenectomy in patients with splenomegaly. Typically, this has been done with the use of metallic coils, but precise placement of the first deposited coil may be limited. The Amplatzer vascular plug (AVP) may be used to accomplish precise proximal splenic artery embolization. MATERIALS AND METHODS Fourteen patients had proximal splenic artery embolization performed with the AVP. Thirteen were performed to allow splenic salvage after blunt trauma and one was performed before splenectomy for massive splenomegaly. Devices ranging in diameter from 8 to 12 mm were placed through 5-F or 6-F guiding catheters. Desired AVP location was distal to the dorsal pancreatic artery and proximal to the most peripheral pancreatica magna branch. Test injections of contrast agent were performed after approximately 5 minutes and then at 3-5-minute intervals until occlusion was seen. If this was not noted by 15 minutes, an adjunctive closure method was chosen. Computed tomography (CT) follow-up was performed in all patients. RESULTS Device placement in the desired location was successful in all cases, with device repositioning required in two. Occlusion took an average of approximately 10 minutes. Additional coils placed in three patients could all be packed into a tight configuration. A second AVP was placed in one patient. There were no complications of the procedures. Follow-up CT images showed no evidence of migration or recanalization of any of the devices. Minimal artifact was noted from the AVP on CT. CONCLUSION In this preliminary series, use of the AVP allowed for precise proximal splenic artery embolization.

Desmoid tumor-ureteral fistula in Gardner's syndrome

Gardners syndrome (GS) is complicated by abdominal desmoid tumors in approximately 8% of cases. We describe two cases of ureteral obstruction and fistulization due to rapidly enlarging desmoid tumors. Initial management consisted of placement of ureteral stents to provide urine drainage from the kidney as well as from the collection in the cavities within the desmoid tumors.

Pneumothorax and pneumomediastinum after laparoscopic surgery

Pneumothorax, pneumomediastinum, pneumopericardium, and subcutaneous emphysema have been described as complications of laparoscopy. This study evaluates the incidence and significance of these extra alveolar collections of air. We found that pneumomediastinum with or without pneumothorax was not associated with significant morbidity and is more likely after laparoscopic fundoplication than other laparoscopic surgeries. The presence of pneumomediastinum after fundoplication is a normal finding. However, pneumothorax has clinical significance and should be considered pathological.

Blunt Splenic Injury: Use of a Multidetector CT–based Splenic Injury Grading System and Clinical Parameters for Triage of Patients at Admission

PURPOSE To assess the use of a dual-phase multidetector computed tomography (CT)-based grading system alone and in combination with assessment of clinical parameters at triage of patients with blunt splenic injury for determination of appropriate treatment (observation, splenic artery embolization [SAE], or splenic surgery). MATERIALS AND METHODS This HIPAA-compliant retrospective study was approved by the institutional review board, and the requirement for informed consent was waived. Between January 2009 and July 2011, 171 hemodynamically stable patients with blunt splenic injury underwent multidetector CT at admission to the hospital. Images were reviewed by applying a multidetector CT-based grading system, and the amount of hemoperitoneum was quantified. Demographic data, vital signs, laboratory values, injury severity score, abbreviated injury severity, final treatment decision, and success of nonsurgical treatment were reviewed. Receiver operating characteristic curves and stepwise logistic regression analyses were performed to determine the optimal parameters for effective triage of patients. RESULTS One hundred seventy one patients with splenic injury underwent multidetector CT. At triage, clinical treatment decisions were made, and patients received either observation (85 of 171 [50%]) or splenic intervention (surgery, 19 of 171 [11%] or splenic angiography, 67 of 171 [39%]). Four patients underwent SAE after unsuccessful observation. Six of 171 (3.5%) other patients received unsuccessful nonsurgical treatment with SAE. No patients who received observation required splenectomy. Areas under the receiver operating characteristic curve (AUCs) showed that the CT grading system was the best individual predictor of successful observation (AUC, 0.95), and stepwise logistic regression analysis results showed that multidetector CT grade and the abbreviated injury scale score (AUC, 0.97; P = .02) were the best combination of variables for selection of patients for observation versus splenic intervention. The combination of abbreviated injury scale score, systolic blood pressure reading, and serum glucose level was the best triage model for decision making between splenectomy and SAE (AUC, 0.84). CONCLUSION The best individual predictor of successful observation in patients with blunt splenic injury was the CT-based grading system. Multidetector CT grade and abbreviated injury scale score were the best combination of variables for selection of patients for observation versus splenic intervention.