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Abstract No. 346: Subcutaneous Venous Chest Port Outcomes: Is Pocket Fixation Necessary?
Abstract No. 343 EE
ex-vivo control samples, where no ‘heat sink’ effect is present, using the same energy delivery metrics.
CT Guided Injection of the Scapulothoracic Bursa. W.A. Pace1, C.O. Hampson1, G.E. Gentchos1, C.E. Gentchos2; 1University of Vermont College of Medicine, Burlington, VT; 2Concord Orthopedics, Concord, NH.
RESULTS: Ablation dimensions were similar in ex vivo ‘control’ conditions. Both energy types are affected by ‘heat sink’ near large vessels in vivo; however, RF energy is clearly more affected by ‘heat sink’ than microwave energy.
PURPOSE: Scapulothoracic bursitis is rare cause of posterior shoulder pain, subscapular pain and crepitus. Conservative management with corticosteroid and local anesthetic injection is an effective treatment and may serve as a diagnostic test for this condition. Injection techniques of the bursa without imaging guidance and with fluoroscopic guidance have been described, although these approaches may not ensure deposition of the corticosteroid within the bursa.
CONCLUSION: Tissue properties and local anatomy may explain ‘heat sink’ as a combination of ‘heat sink’ and ‘energy sink’ for monopolar RF energy (thermal and electrical influences) and ‘heat sink’ alone (thermal influences) for microwave energy. Energy sink effects for RF are due to diversion of RF energy toward highly conductive blood vessels. This is consistent with the 5:1 electrical conductivity () ratio of blood to parenchymal liver tissue. Microwave energy deposition is less affected, as differences in dielectric constant (⬃√r) between the tissues are smaller (⬃10-15%). Thermal convection losses due to blood perfusion affect ablation sizes for both types of energy.
The purpose of this educational exhibit is to review the clinical manifestations of scapulothoracic bursitis and the anatomy of the scapulothoracic articulation. We will describe a technique for CT guided injection of the bursa which ensures accurate and safe placement of local anesthetic and corticosteroid. To our knowledge, this has not been formally reported in the literature. MATERIALS & METHODS: This educational exhibit will display illustrations of the scapulothoracic anatomy, CT images of injection techniques, and ancillary findings on CT which may cause scapulothoracic pain. TEACHING POINTS: After reviewing this educational exhibit, the radiologist will have an understanding of: 1. The clinical manifestations and treatment options for scapulothoracic bursitis. 2. The anatomy of the scapulothoracic articulation. 3. CT guided technique for scapulothoracic injection. 4. Ancillary findings on CT which may cause scapulothoracic bursitis or pain. Abstract No. 344 Comparison of ‘Heat Sink’ Effect for RF and Microwave Energies in an In Vivo Porcine Liver Model. J. Paulus1, B. Smith4, C. Ladtkow1, A. Ross1, M. Waugh3, R. Nelson2; 1Covidien Energy-Based Devices, Boulder, CO; 2 Duke University Medical Center - Radiology, Durham, NC; 3Duke University Medical Center - Pathology, Durham, NC; 4Radiology Associates of the Fox Valley, S.C., Neenah, WI. PURPOSE: Previous studies compare heat sink effects for commercial devices with different physical constructions and energy delivery algorithms. This study explores how the two energy types interact with large (⬎4 mm) vessels using similar electrode/antenna sizes and equivalent delivered energy. MATERIALS & METHODS: 14 domestic pigs were used in the study, performing a single ablation with ultrasound guidance in each of the four lobes. 25 kJ RF or 20 kJ microwave energy was applied per ablation, the 5 kJ energy difference accounting for return pad losses. Energy sources were non-commercial devices. Animals were euthanized immediately following ablations; livers were excised and sectioned in 3-4 mm slices. Slices were scanned digitally to analyze ablation dimensions and vessel locations. Histology was performed using H&E and NADH stains to examine effects up to vessels and identify thrombosis. Scanned slices were analyzed using a MATLAB algorithm to identify ablation boundaries and vessel location. A ‘center of mass’ method was used to identify shifts in ablation dimensions relative to vessel locations. Ablation sizes were compared to S128
Abstract No. 345 Hemostatic Efficasy of Chitosan Based Bandage for Closure of Percutaneous Arterial Access Sites: An Experimental Study in Heparinized Ovine Model. D. Pavcnik, P. Kranokpiraksa, B.T. Uchida, H. Kakizawa, F.S. Keller, J. Rosch; OHSU - Dotter Institute, Portland, OR. PURPOSE: To evaluate in ovine model the hemostatic efficacy of the chitosan based closure device and compare it to that of standard manual compression after SFA catheterization with 8 F sheath. MATERIALS & METHODS: Nine heparinized sheep underwent percutaneous puncture of bilateral SFAs followed by placement of an 8F sheath for 5 minutes. Upon sheath removal, the puncture sites were randomized to achieve hemostasis between the chitosan based bandage and manual compression for 5 minutes. After pressure release, femoral angiography was done to evaluate hemostasis. If bleeding was found, continued pressure and repeat angiography were done at 2.5 minute intervals until successful hemostasis. RESULTS: The chitosan based bandage exhibited successful hemostasis within 5 minutes in seven of nine (77.8%0 experiments. The mean time to hemostasis was significantly shortened with chitosan bandage (6.94⫹/- 3.91 minutes) compared with that of the manual compression (10.8⫹/min)(p⫽0.019). All nine (100%) experiments using hemostatic bandage showed patency of femoral artery and demonstrated less hematoma (2/9) than in control group (8/9). CONCLUSION: Use of chitosan based hemostatic bandage upon femoral arterial sheath removal significantly reduced time to hemostasis without increased risk of complication compared to manual compression. Proper application of the bandage is necessary to shorten and hematoma formation. It can be expected that the tested bandage, presently widely used in trauma patients, will have a role in hemostasis after diagnostic and endovascular procedures. Abstract No. 346 Subcutaneous Venous Chest Port Outcomes: Is Pocket Fixation Necessary? K.D. Perrich1, A.M. Silas1, R.M. Linville2, A.R. Forauer1, N.J. McNulty1; 1Dartmouth-Hitchcock Medical Center, Lebanon, NH; 2Dartmouth Medical School, Hanover, NH.
PURPOSE: Standard surgical technique of subcutaneous venous port placement describes dissection of the port pocket to the pectoralis fascia and suture fixation of the port to the fascia to prevent rotation, or flipping of the device within the pocket. This investigation addresses the incidence of port rotation or flipping in ports placed without suture fixation. MATERIALS & METHODS: Between 10/8/04 and 10/19/ 07, 558 subcutaneous venous chest ports were placed at our institution. 24 of these cases were excluded from this study: 22 lacked follow-up and 2 were sutured into the pocket. A retrospective review of the remaining 534 ports was performed. Ports were placed using standard surgical technique, with the exception that none were sutured into the pocket. Mean duration of port use, total number of port days, complications, and indications for removal were assessed. Results were compared with the literature. RESULTS: Mean duration of port usage was 341 days (182,235 total port days, range 1 to 1279 days). Of the 534 ports placed, there was one port flip that resulted in malfunction and necessitated port removal (0.2%). No complication due to port migration was noted. Other complications necessitating port removal included: infection 26 (5%), thrombosis 2 (⬍1%), catheter fracture/pinch 1 (⬍1%), pain 2 (⬍1%), and skin erosion 3 (1%). There were 2 arrhythmias at time of placement; neither required port removal. The overall short and long term complication rate was 7%. CONCLUSION: The incidence of port rotation or flipping is extremely low in the absence of suture fixation of the port into the pocket. The incidence we report is concordant with that previously published, although most prior reports do not specify if this surgical step was performed. Suture fixation of the port, in our experience, is an unnecessary step and may negatively impact port removal. Presence of sutures antectodally requires more extensive soft tissue dissection to free the port and results in longer procedure time. Abstract No. 347 Incidence and Time to Mechanical Pleurodesis for Malignant Pleural Effusions Treated by Tunneled Pleural Catheters. S. Pradhan1,2, R. Thornton1, Z. Miller3, A. Covey1, G. Getrajdman1; 1Memorial Sloan Kettering Cancer Center, New York, NY; 2Weill Cornell Medical Center, New York, NY; 3Columbia University Medical Center, New York, NY.
MATERIALS & METHODS: 249 consecutive patients (71 males, 178 females; age range 19-91) with malignant pleural effusion treated by TPC between 2002-2006 were identified by retrospective review of IR billing records. Diagnoses were breast cancer in 94, lung cancer in 52, gastrointestinal (esophageal, colon, gastric, pancreas, cholangiocarcinoma) in 36, ovarian/gynecologic in 18, lymphoma in 13, urothelial/renal cell carcinoma in 9, sarcoma in 7, head & neck/thyroid in 9, skin in 2, prostate in 2, multiple myeloma in 2, malignant nerve sheath tumor in 1, and unknown primary in 4. 64 patients had prior chemical pleurodesis. Diagnosis groups were compared for the incidence and time to MP permitting catheter removal. RESULTS: Of the 249 patients with TPC placement, catheters were removed from 72 (62 for MP, 10 for other
CONCLUSION: When malignant pleural effusion is treated by TPC placement, MP permits catheter removal in about one-fourth of patients within two months on average. Contrary to previously published articles, we found no association between diagnosis and the incidence of MP. Abstract No. 348 EE The Role of CT Angiography in the Workup of GI Bleeding. D. Kennedy, J.D. Prologo, D. Fischman, D.I. Rosenblum; Metrohealth Medical Center, Cleveland, OH. PURPOSE: Lower gastrointestinal (GI) tract bleeding is a significant cause of patient morbidity and mortality. The intermittent nature of this disease makes the establishment of reproducible diagnostic algorithms difficult. The sensitivity of mesenteric catheter angiography has historically been variable, and positivity rates have been reported as low as 3%. Multiple adjunctive variables have been proposed to increase the positivity rate and sensitivity of invasive angiography, including pretest scintigraphy and/or correlation with clinical variables such as hemoglobin trend, blood pressure, or transfusion requirements. Recently, the development of multidetector CT angiography (CTA) protocols has afforded a noninvasive option for documentation and localization of lower GI bleeds. We report initial experience utilizing CTA as a first line modality in the evaluation of patients with symptomatic lower GI bleeding. MATERIALS & METHODS: Outcome analyses were performed regarding the clinical courses of patients who underwent dedicated CTA for GI bleed between September 2004 and September 2008. The CTA protocol involved unenhanced imaging of the abdomen and pelvis followed by serial axial acquisition at 0.9mm with 80-100 ml of intravenous contrast delivered via automated bolus triggering software during an enteric phase of enhancement (120 kV; 405 mA; pitch, 0.923). Exams were interpreted as positive for GI bleed if hyperattenuating contrast material could be identified in the bowel lumen during the enhanced phase of scanning.
POSTER SESSIONS
PURPOSE: To describe patterns of mechanical pleurodesis (MP) for patients with malignant pleural effusion treated by a tunneled pleural catheter (TPC).
indications). MP permitted catheter removal in 62(25%) after mean median 43.5 days (range 6-393 days): 24 patients with breast cancer (26%) after median 44.5 days (7-151 days); 11 with lung cancer (21%) after median 53 days (6-224 days); 7 with gastrointestinal tumors (19%) after median 33 days (4-102 days); 6 with gynecologic malignancy (33%) after median 51 days (15-150 days); 5 with lymphoma (38%) after median 85 days (57-393 days); and 9 others (including patients with prostate, head and neck, urothelial, and unknown primary tumors). No patient whose catheter was removed for MP required subsequent additional ipsilateral pleural drainage. Based on chi-squared analysis, there was no significant difference in the incidence of MP among the cancer types (p⫽0.57).
TEACHING POINTS: Seventy eight exams were performed during the outlined time period. The overall sensitivity, specificity, positive and negative predictive values for detection of GI bleeding, utilizing clinical course and subsequent exams (endoscopy, mesenteric angiography, nuclear scintigraphy) for confirmation of the presence or absence of significant GI bleeding were 80% (12 of 15), 97% (61 of 63), 86% (12 of 14) and 95% (61 of 64), respectively. All confirmed positive CTs were anatomically concordant with the site of hemorrhage depicted on the confirmatory study. Multidector CTA protocols are an accurate rapid noninvaS129
ex-vivo control samples, where no ‘heat sink’ effect is present, using the same energy delivery metrics.
CT Guided Injection of the Scapulothoracic Bursa. W.A. Pace1, C.O. Hampson1, G.E. Gentchos1, C.E. Gentchos2; 1University of Vermont College of Medicine, Burlington, VT; 2Concord Orthopedics, Concord, NH.
RESULTS: Ablation dimensions were similar in ex vivo ‘control’ conditions. Both energy types are affected by ‘heat sink’ near large vessels in vivo; however, RF energy is clearly more affected by ‘heat sink’ than microwave energy.
PURPOSE: Scapulothoracic bursitis is rare cause of posterior shoulder pain, subscapular pain and crepitus. Conservative management with corticosteroid and local anesthetic injection is an effective treatment and may serve as a diagnostic test for this condition. Injection techniques of the bursa without imaging guidance and with fluoroscopic guidance have been described, although these approaches may not ensure deposition of the corticosteroid within the bursa.
CONCLUSION: Tissue properties and local anatomy may explain ‘heat sink’ as a combination of ‘heat sink’ and ‘energy sink’ for monopolar RF energy (thermal and electrical influences) and ‘heat sink’ alone (thermal influences) for microwave energy. Energy sink effects for RF are due to diversion of RF energy toward highly conductive blood vessels. This is consistent with the 5:1 electrical conductivity () ratio of blood to parenchymal liver tissue. Microwave energy deposition is less affected, as differences in dielectric constant (⬃√r) between the tissues are smaller (⬃10-15%). Thermal convection losses due to blood perfusion affect ablation sizes for both types of energy.
The purpose of this educational exhibit is to review the clinical manifestations of scapulothoracic bursitis and the anatomy of the scapulothoracic articulation. We will describe a technique for CT guided injection of the bursa which ensures accurate and safe placement of local anesthetic and corticosteroid. To our knowledge, this has not been formally reported in the literature. MATERIALS & METHODS: This educational exhibit will display illustrations of the scapulothoracic anatomy, CT images of injection techniques, and ancillary findings on CT which may cause scapulothoracic pain. TEACHING POINTS: After reviewing this educational exhibit, the radiologist will have an understanding of: 1. The clinical manifestations and treatment options for scapulothoracic bursitis. 2. The anatomy of the scapulothoracic articulation. 3. CT guided technique for scapulothoracic injection. 4. Ancillary findings on CT which may cause scapulothoracic bursitis or pain. Abstract No. 344 Comparison of ‘Heat Sink’ Effect for RF and Microwave Energies in an In Vivo Porcine Liver Model. J. Paulus1, B. Smith4, C. Ladtkow1, A. Ross1, M. Waugh3, R. Nelson2; 1Covidien Energy-Based Devices, Boulder, CO; 2 Duke University Medical Center - Radiology, Durham, NC; 3Duke University Medical Center - Pathology, Durham, NC; 4Radiology Associates of the Fox Valley, S.C., Neenah, WI. PURPOSE: Previous studies compare heat sink effects for commercial devices with different physical constructions and energy delivery algorithms. This study explores how the two energy types interact with large (⬎4 mm) vessels using similar electrode/antenna sizes and equivalent delivered energy. MATERIALS & METHODS: 14 domestic pigs were used in the study, performing a single ablation with ultrasound guidance in each of the four lobes. 25 kJ RF or 20 kJ microwave energy was applied per ablation, the 5 kJ energy difference accounting for return pad losses. Energy sources were non-commercial devices. Animals were euthanized immediately following ablations; livers were excised and sectioned in 3-4 mm slices. Slices were scanned digitally to analyze ablation dimensions and vessel locations. Histology was performed using H&E and NADH stains to examine effects up to vessels and identify thrombosis. Scanned slices were analyzed using a MATLAB algorithm to identify ablation boundaries and vessel location. A ‘center of mass’ method was used to identify shifts in ablation dimensions relative to vessel locations. Ablation sizes were compared to S128
Abstract No. 345 Hemostatic Efficasy of Chitosan Based Bandage for Closure of Percutaneous Arterial Access Sites: An Experimental Study in Heparinized Ovine Model. D. Pavcnik, P. Kranokpiraksa, B.T. Uchida, H. Kakizawa, F.S. Keller, J. Rosch; OHSU - Dotter Institute, Portland, OR. PURPOSE: To evaluate in ovine model the hemostatic efficacy of the chitosan based closure device and compare it to that of standard manual compression after SFA catheterization with 8 F sheath. MATERIALS & METHODS: Nine heparinized sheep underwent percutaneous puncture of bilateral SFAs followed by placement of an 8F sheath for 5 minutes. Upon sheath removal, the puncture sites were randomized to achieve hemostasis between the chitosan based bandage and manual compression for 5 minutes. After pressure release, femoral angiography was done to evaluate hemostasis. If bleeding was found, continued pressure and repeat angiography were done at 2.5 minute intervals until successful hemostasis. RESULTS: The chitosan based bandage exhibited successful hemostasis within 5 minutes in seven of nine (77.8%0 experiments. The mean time to hemostasis was significantly shortened with chitosan bandage (6.94⫹/- 3.91 minutes) compared with that of the manual compression (10.8⫹/min)(p⫽0.019). All nine (100%) experiments using hemostatic bandage showed patency of femoral artery and demonstrated less hematoma (2/9) than in control group (8/9). CONCLUSION: Use of chitosan based hemostatic bandage upon femoral arterial sheath removal significantly reduced time to hemostasis without increased risk of complication compared to manual compression. Proper application of the bandage is necessary to shorten and hematoma formation. It can be expected that the tested bandage, presently widely used in trauma patients, will have a role in hemostasis after diagnostic and endovascular procedures. Abstract No. 346 Subcutaneous Venous Chest Port Outcomes: Is Pocket Fixation Necessary? K.D. Perrich1, A.M. Silas1, R.M. Linville2, A.R. Forauer1, N.J. McNulty1; 1Dartmouth-Hitchcock Medical Center, Lebanon, NH; 2Dartmouth Medical School, Hanover, NH.
PURPOSE: Standard surgical technique of subcutaneous venous port placement describes dissection of the port pocket to the pectoralis fascia and suture fixation of the port to the fascia to prevent rotation, or flipping of the device within the pocket. This investigation addresses the incidence of port rotation or flipping in ports placed without suture fixation. MATERIALS & METHODS: Between 10/8/04 and 10/19/ 07, 558 subcutaneous venous chest ports were placed at our institution. 24 of these cases were excluded from this study: 22 lacked follow-up and 2 were sutured into the pocket. A retrospective review of the remaining 534 ports was performed. Ports were placed using standard surgical technique, with the exception that none were sutured into the pocket. Mean duration of port use, total number of port days, complications, and indications for removal were assessed. Results were compared with the literature. RESULTS: Mean duration of port usage was 341 days (182,235 total port days, range 1 to 1279 days). Of the 534 ports placed, there was one port flip that resulted in malfunction and necessitated port removal (0.2%). No complication due to port migration was noted. Other complications necessitating port removal included: infection 26 (5%), thrombosis 2 (⬍1%), catheter fracture/pinch 1 (⬍1%), pain 2 (⬍1%), and skin erosion 3 (1%). There were 2 arrhythmias at time of placement; neither required port removal. The overall short and long term complication rate was 7%. CONCLUSION: The incidence of port rotation or flipping is extremely low in the absence of suture fixation of the port into the pocket. The incidence we report is concordant with that previously published, although most prior reports do not specify if this surgical step was performed. Suture fixation of the port, in our experience, is an unnecessary step and may negatively impact port removal. Presence of sutures antectodally requires more extensive soft tissue dissection to free the port and results in longer procedure time. Abstract No. 347 Incidence and Time to Mechanical Pleurodesis for Malignant Pleural Effusions Treated by Tunneled Pleural Catheters. S. Pradhan1,2, R. Thornton1, Z. Miller3, A. Covey1, G. Getrajdman1; 1Memorial Sloan Kettering Cancer Center, New York, NY; 2Weill Cornell Medical Center, New York, NY; 3Columbia University Medical Center, New York, NY.
MATERIALS & METHODS: 249 consecutive patients (71 males, 178 females; age range 19-91) with malignant pleural effusion treated by TPC between 2002-2006 were identified by retrospective review of IR billing records. Diagnoses were breast cancer in 94, lung cancer in 52, gastrointestinal (esophageal, colon, gastric, pancreas, cholangiocarcinoma) in 36, ovarian/gynecologic in 18, lymphoma in 13, urothelial/renal cell carcinoma in 9, sarcoma in 7, head & neck/thyroid in 9, skin in 2, prostate in 2, multiple myeloma in 2, malignant nerve sheath tumor in 1, and unknown primary in 4. 64 patients had prior chemical pleurodesis. Diagnosis groups were compared for the incidence and time to MP permitting catheter removal. RESULTS: Of the 249 patients with TPC placement, catheters were removed from 72 (62 for MP, 10 for other
CONCLUSION: When malignant pleural effusion is treated by TPC placement, MP permits catheter removal in about one-fourth of patients within two months on average. Contrary to previously published articles, we found no association between diagnosis and the incidence of MP. Abstract No. 348 EE The Role of CT Angiography in the Workup of GI Bleeding. D. Kennedy, J.D. Prologo, D. Fischman, D.I. Rosenblum; Metrohealth Medical Center, Cleveland, OH. PURPOSE: Lower gastrointestinal (GI) tract bleeding is a significant cause of patient morbidity and mortality. The intermittent nature of this disease makes the establishment of reproducible diagnostic algorithms difficult. The sensitivity of mesenteric catheter angiography has historically been variable, and positivity rates have been reported as low as 3%. Multiple adjunctive variables have been proposed to increase the positivity rate and sensitivity of invasive angiography, including pretest scintigraphy and/or correlation with clinical variables such as hemoglobin trend, blood pressure, or transfusion requirements. Recently, the development of multidetector CT angiography (CTA) protocols has afforded a noninvasive option for documentation and localization of lower GI bleeds. We report initial experience utilizing CTA as a first line modality in the evaluation of patients with symptomatic lower GI bleeding. MATERIALS & METHODS: Outcome analyses were performed regarding the clinical courses of patients who underwent dedicated CTA for GI bleed between September 2004 and September 2008. The CTA protocol involved unenhanced imaging of the abdomen and pelvis followed by serial axial acquisition at 0.9mm with 80-100 ml of intravenous contrast delivered via automated bolus triggering software during an enteric phase of enhancement (120 kV; 405 mA; pitch, 0.923). Exams were interpreted as positive for GI bleed if hyperattenuating contrast material could be identified in the bowel lumen during the enhanced phase of scanning.
POSTER SESSIONS
PURPOSE: To describe patterns of mechanical pleurodesis (MP) for patients with malignant pleural effusion treated by a tunneled pleural catheter (TPC).
indications). MP permitted catheter removal in 62(25%) after mean median 43.5 days (range 6-393 days): 24 patients with breast cancer (26%) after median 44.5 days (7-151 days); 11 with lung cancer (21%) after median 53 days (6-224 days); 7 with gastrointestinal tumors (19%) after median 33 days (4-102 days); 6 with gynecologic malignancy (33%) after median 51 days (15-150 days); 5 with lymphoma (38%) after median 85 days (57-393 days); and 9 others (including patients with prostate, head and neck, urothelial, and unknown primary tumors). No patient whose catheter was removed for MP required subsequent additional ipsilateral pleural drainage. Based on chi-squared analysis, there was no significant difference in the incidence of MP among the cancer types (p⫽0.57).
TEACHING POINTS: Seventy eight exams were performed during the outlined time period. The overall sensitivity, specificity, positive and negative predictive values for detection of GI bleeding, utilizing clinical course and subsequent exams (endoscopy, mesenteric angiography, nuclear scintigraphy) for confirmation of the presence or absence of significant GI bleeding were 80% (12 of 15), 97% (61 of 63), 86% (12 of 14) and 95% (61 of 64), respectively. All confirmed positive CTs were anatomically concordant with the site of hemorrhage depicted on the confirmatory study. Multidector CTA protocols are an accurate rapid noninvaS129