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Interstitial laser photocoagulation in canine lung: A preliminary investigation of a new treatment for lung cancer
ABSTRACTS
5-3
Studyof Relationship BetweenCardiac Functionand Carotid Perfusion in an Animal Model, Using Quantitative Color Velocity Imaging Sjirk J. Westra, M.D., Denis Levy, M.D., Jennifer Hill, B.S., James Sayre, Ph.D.,JohnRobert,S.R.A., FernandoVinuela, M.D. Universityof California at Los Angeles Schoolof Medicine.
Quantitative Color Velocity Imaging (CVI-QTM) is a new ultrasonogesphic technique to quantify volume flow (VF) in blood vessels. Objective: To use CVI-QTM VF measurements to study the relationship between cardiac function and ca~dd blood flow (CBF). Methods: In seven swine, an m'teriovenous fistula was created between the common carotid artery (CCA) and the juguinr vein. CBF was meastwed extamally with CVI-QTM, and compared with continuous VF readings from a Transonin TM probe clamped around the CCA, cardiac output (CO, through Swan-Ganz catheter thermodilufion method), heart rate, and mean arterial blood pressure. CO and CBF were varied by 1. opening or closing the AV fistula; 2. hyperventilation; 3. withdrawing or infusing intravascular fluids; 4. infusing medications (dopamine, B.blocker). Results: We produced a wide range of hemodynamic conditions (high- and low output cardiac failure, hypovolemic shock, vaanpressor overdose). CVI-QTM VF measurements correlated well with Transonic TM readings, but were less reproducible. CBF autoregulntion compensated for changes in CO. CVI-QTM VF waveform analysis revealed marked variability of CBF resistance in different bemodynamic states. Contusions: CVI-QTMis a valuable noninvasive technique to study the relationship between CBF autorcgulation and cardiac function. These results are applicable to children undergoing complex cardiovascular interventions.
5-5
Interstitial Laser Photocoagulation in Canine Lung: A Preliminary Investigation of a New Treatment for Lung Cancer Brian W. Goodacre, M.D., N.J. Finn, C.P. Nolsoe, O. Esch, G.R. Wittich, E. vanSonnenberg. University of Texas Medical Branch.
To determine the feasibility and safety of interstitial laser photocoagulation in canine lung tissue. Method and Materials: Acute studies were performed with 4 anaesthetized canines. Percutananus, intra-pacenchymal placement of a guiding needle was accomplished with fiuoroscopic guidance. An 800 micron laser fiber (Dittoed Ltd., UK) was introduced coaxially. Multiple lesions were created, varying power level and activation time. The animals were sacrificed and lesions were examined grossly, photographed, and fixed for microscopic evaluation. Dosimetry was studied with creation of a series of lesions in 4 inflated ex-vivo canine lungs. Results: In-rive studies: Power levels f~orn 1 to 4 Watts were applied for up to 10 minutes. No perceptible pneumothorax was visible with fluoroscopy. Post-mortem examination revealed no evidence of hemorrhage or other acute complications. One instance of focal diaphragmatic thermal eoagulatinn related to creation of a basal lung lesion was noted. Ex-vivo lung: Power levels of 2, 3, and 4 Watts were applied for 350, 172, and 114 seconds respectively. Average lesion size was 9x4mm, each with a similar elliptical shape. Conclusions: Interstitial laser photocoagulation can be used to create lesions of predictable size and dimensions in lung tissue, with few acute complications. Further studies with tumor model ablation are warranted.
1144
Vol. 2, No. 12, December 1995
5-4
HRCT in the Acute Pulmonary Exacerbation of Cystic Fibrosis: Evaluation of Acute Findings, Reversibility and Clinical Correlation Rosita M. Shah, M.D., W. Sexauer, B.J. Ostrum, S. Fiel, A.C. Friedman. Medical College of Pennsylvania.
PURPOSE:I) Compare HRCT of adult cystic fibrosis(CF) at the onset of acute exacerbations with asymptematic CP patients 2) Correlate HRCT evidence of improvement following an exacerbation with clinical parameters. METHOD:Prospective double blind review of CXR's and HHCT obtained at the onset of exacerbations and following two week hospitalizations in 17patlents (mean 31yo) and in i0 patients(mean 32yo) n o t experiencing pulmonary symptoms. Bronchiectasis as determined by a modiffed scoring system(Bhalla) was correlated with baseline pulmonary function. Reversibility of peribronchial thickening, mucous plugging, atelectasis/consolidation, centrilobular nodules and mosaic perfusion was correlated with clinical improvement following the exacerbation. RESULTS:Bronghiectasis and peribronchial thickening were seen in all patients, correlating with clinical severity(p<.0]). No significant difference in the frequency of peribronchial thlckening(100%), mucous plugging(95%), atelectasis/consslidation(18%) or centrilobular nodules(S5%) occurred between symptomatic and asymptomatie groups. Mosaic perfusion was seen more frequently during exacerbations(35%). Partial resolution of mucous plugging and/or centrilobular nodules occurred in 40% of exacerbations hut did not correlate(p>,20) with mild changes in PFT's. Perlbronchial thickening, atelectasis/consolidation and mosaic perfusion did not improve. CONCLUSION: HRCT in the exacerbation of CF does not differ from baseline pulmonary abnormalities. Although HRCT can accurately assess severity of disease, correlation with clinical improvement is poor.
5-6
Fibrin Sheath Stripping From Occluded Catheters Utilizing Braiding Maneuver Murat H. Sor, M.D., Michael V. Korona, Edward Druy. George Washington University.
pURPOSE: With prolonged
indwelling of venous catheters, occlusion secondary to fibrin sheath formation i n c r e a s e s . Several methods for removal of fibrin sheaths stripping including gooseneck snaring have been described. However, often a fibrin sheath tethers the indwelling catheter to the SVC making engagement with the snare impossible. We submit an alternate method for engaging and stripping occluded catheters. ~TERZALS ~ METHODS: W e n a fibrin sheath detected to be the cause of a subclavian or IJ catheter occlusion, stripping with a gooseneck snare from a femoral approach is attempted. If unable to engage the catheter with the snare, alternate braiding method attempted. Gooseneck snare exchanged f o r R I M catheter. RIM advanced as close to the site of insertion as possible. Then a Tip deflecting wire (TDW) is introduced into the RIM. The unit is then engaged with the catheter by torquing the RIM. Next, the TDW is engaged, causing further tightening. The unit is then pulled infe~iorly, stripping the catheter of its fibrin sheath. RESULTS: TweDty patients referred for malfunctioning catheters had fibrin sheaths diagnosed. Six of these were refractory to gooseneck snaring, presumably due to fibrin sheath tethering. All were subsequently successfully treated utilizing the alternate braiding method. In one patient, the alternate method employed initially. CONCLUSION: our alternative method fez fibrin sheath stripping allows engagement of a malfunctioning catheter e v e n if it tethered by fibrin sheath. Considering the lower cost of this braiding method as compared to gooseneck snaring, we suggest it as a primary approach for fibrin sheath stripping.
5-3
Studyof Relationship BetweenCardiac Functionand Carotid Perfusion in an Animal Model, Using Quantitative Color Velocity Imaging Sjirk J. Westra, M.D., Denis Levy, M.D., Jennifer Hill, B.S., James Sayre, Ph.D.,JohnRobert,S.R.A., FernandoVinuela, M.D. Universityof California at Los Angeles Schoolof Medicine.
Quantitative Color Velocity Imaging (CVI-QTM) is a new ultrasonogesphic technique to quantify volume flow (VF) in blood vessels. Objective: To use CVI-QTM VF measurements to study the relationship between cardiac function and ca~dd blood flow (CBF). Methods: In seven swine, an m'teriovenous fistula was created between the common carotid artery (CCA) and the juguinr vein. CBF was meastwed extamally with CVI-QTM, and compared with continuous VF readings from a Transonin TM probe clamped around the CCA, cardiac output (CO, through Swan-Ganz catheter thermodilufion method), heart rate, and mean arterial blood pressure. CO and CBF were varied by 1. opening or closing the AV fistula; 2. hyperventilation; 3. withdrawing or infusing intravascular fluids; 4. infusing medications (dopamine, B.blocker). Results: We produced a wide range of hemodynamic conditions (high- and low output cardiac failure, hypovolemic shock, vaanpressor overdose). CVI-QTM VF measurements correlated well with Transonic TM readings, but were less reproducible. CBF autoregulntion compensated for changes in CO. CVI-QTM VF waveform analysis revealed marked variability of CBF resistance in different bemodynamic states. Contusions: CVI-QTMis a valuable noninvasive technique to study the relationship between CBF autorcgulation and cardiac function. These results are applicable to children undergoing complex cardiovascular interventions.
5-5
Interstitial Laser Photocoagulation in Canine Lung: A Preliminary Investigation of a New Treatment for Lung Cancer Brian W. Goodacre, M.D., N.J. Finn, C.P. Nolsoe, O. Esch, G.R. Wittich, E. vanSonnenberg. University of Texas Medical Branch.
To determine the feasibility and safety of interstitial laser photocoagulation in canine lung tissue. Method and Materials: Acute studies were performed with 4 anaesthetized canines. Percutananus, intra-pacenchymal placement of a guiding needle was accomplished with fiuoroscopic guidance. An 800 micron laser fiber (Dittoed Ltd., UK) was introduced coaxially. Multiple lesions were created, varying power level and activation time. The animals were sacrificed and lesions were examined grossly, photographed, and fixed for microscopic evaluation. Dosimetry was studied with creation of a series of lesions in 4 inflated ex-vivo canine lungs. Results: In-rive studies: Power levels f~orn 1 to 4 Watts were applied for up to 10 minutes. No perceptible pneumothorax was visible with fluoroscopy. Post-mortem examination revealed no evidence of hemorrhage or other acute complications. One instance of focal diaphragmatic thermal eoagulatinn related to creation of a basal lung lesion was noted. Ex-vivo lung: Power levels of 2, 3, and 4 Watts were applied for 350, 172, and 114 seconds respectively. Average lesion size was 9x4mm, each with a similar elliptical shape. Conclusions: Interstitial laser photocoagulation can be used to create lesions of predictable size and dimensions in lung tissue, with few acute complications. Further studies with tumor model ablation are warranted.
1144
Vol. 2, No. 12, December 1995
5-4
HRCT in the Acute Pulmonary Exacerbation of Cystic Fibrosis: Evaluation of Acute Findings, Reversibility and Clinical Correlation Rosita M. Shah, M.D., W. Sexauer, B.J. Ostrum, S. Fiel, A.C. Friedman. Medical College of Pennsylvania.
PURPOSE:I) Compare HRCT of adult cystic fibrosis(CF) at the onset of acute exacerbations with asymptematic CP patients 2) Correlate HRCT evidence of improvement following an exacerbation with clinical parameters. METHOD:Prospective double blind review of CXR's and HHCT obtained at the onset of exacerbations and following two week hospitalizations in 17patlents (mean 31yo) and in i0 patients(mean 32yo) n o t experiencing pulmonary symptoms. Bronchiectasis as determined by a modiffed scoring system(Bhalla) was correlated with baseline pulmonary function. Reversibility of peribronchial thickening, mucous plugging, atelectasis/consolidation, centrilobular nodules and mosaic perfusion was correlated with clinical improvement following the exacerbation. RESULTS:Bronghiectasis and peribronchial thickening were seen in all patients, correlating with clinical severity(p<.0]). No significant difference in the frequency of peribronchial thlckening(100%), mucous plugging(95%), atelectasis/consslidation(18%) or centrilobular nodules(S5%) occurred between symptomatic and asymptomatie groups. Mosaic perfusion was seen more frequently during exacerbations(35%). Partial resolution of mucous plugging and/or centrilobular nodules occurred in 40% of exacerbations hut did not correlate(p>,20) with mild changes in PFT's. Perlbronchial thickening, atelectasis/consolidation and mosaic perfusion did not improve. CONCLUSION: HRCT in the exacerbation of CF does not differ from baseline pulmonary abnormalities. Although HRCT can accurately assess severity of disease, correlation with clinical improvement is poor.
5-6
Fibrin Sheath Stripping From Occluded Catheters Utilizing Braiding Maneuver Murat H. Sor, M.D., Michael V. Korona, Edward Druy. George Washington University.
pURPOSE: With prolonged
indwelling of venous catheters, occlusion secondary to fibrin sheath formation i n c r e a s e s . Several methods for removal of fibrin sheaths stripping including gooseneck snaring have been described. However, often a fibrin sheath tethers the indwelling catheter to the SVC making engagement with the snare impossible. We submit an alternate method for engaging and stripping occluded catheters. ~TERZALS ~ METHODS: W e n a fibrin sheath detected to be the cause of a subclavian or IJ catheter occlusion, stripping with a gooseneck snare from a femoral approach is attempted. If unable to engage the catheter with the snare, alternate braiding method attempted. Gooseneck snare exchanged f o r R I M catheter. RIM advanced as close to the site of insertion as possible. Then a Tip deflecting wire (TDW) is introduced into the RIM. The unit is then engaged with the catheter by torquing the RIM. Next, the TDW is engaged, causing further tightening. The unit is then pulled infe~iorly, stripping the catheter of its fibrin sheath. RESULTS: TweDty patients referred for malfunctioning catheters had fibrin sheaths diagnosed. Six of these were refractory to gooseneck snaring, presumably due to fibrin sheath tethering. All were subsequently successfully treated utilizing the alternate braiding method. In one patient, the alternate method employed initially. CONCLUSION: our alternative method fez fibrin sheath stripping allows engagement of a malfunctioning catheter e v e n if it tethered by fibrin sheath. Considering the lower cost of this braiding method as compared to gooseneck snaring, we suggest it as a primary approach for fibrin sheath stripping.