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Papers by David Auth

Research paper thumbnail of Bioengineering : Current Status and Future Implications on Clinical Medicine

The Japanese journal of gastro-enterology, Aug 20, 1996

Research paper thumbnail of A Temperature-Compensated, Low-Voltage Regulator

Research paper thumbnail of Laser Photocoagulation Principles

Research paper thumbnail of Flow Capacity, How Much is Enough, Do We Have it, Do We Need More?

Research paper thumbnail of Handpieces for surgical lasers

The use of concentrated laser irradiation for evaporation of tissue has been well accepted. In pa... more The use of concentrated laser irradiation for evaporation of tissue has been well accepted. In particular, the CO2 laser with its very high absorption coefficient permits surface ablation or linear excavation, providing a well controlled surgical device. Its use through the operating microscope enables non-contact management of surgical therapy with unparalleled convenience and precision. However, in other areas of surgery where deeper tissue coagulation is valuable for better hemostasis, the CO2 laser falls short of the clinical need. The use of deeper penetrating laser wavelengths necessarily reduces the superficially evaporative cutting in much the same manner that coagulating waveforms reduce cutting efficienty in electrosurgical scalpels. We have developed a series of transparent quartz scalpel blades which allow delivery of visible and near infrared laser irradiation to a mechanically incised tissue margin resulting in vastly improved hemostasis.The use of concentrated laser irradiation for evaporation of tissue has been well accepted. In particular, the CO2 laser with its very high absorption coefficient permits surface ablation or linear excavation, providing a well controlled surgical device. Its use through the operating microscope enables non-contact management of surgical therapy with unparalleled convenience and precision. However, in other areas of surgery where deeper tissue coagulation is valuable for better hemostasis, the CO2 laser falls short of the clinical need. The use of deeper penetrating laser wavelengths necessarily reduces the superficially evaporative cutting in much the same manner that coagulating waveforms reduce cutting efficienty in electrosurgical scalpels. We have developed a series of transparent quartz scalpel blades which allow delivery of visible and near infrared laser irradiation to a mechanically incised tissue margin resulting in vastly improved hemostasis.

Research paper thumbnail of Gun Tube Bore Strain

Abstract : A study was undertaken to determine the optimum sensing device for measuring the bore ... more Abstract : A study was undertaken to determine the optimum sensing device for measuring the bore strain of a gun tube during rapid firing. The hostile environment that exists within the gun tube and the general operational requirements of the gun tube place severe requirements on any system considered. After consideration of a number of systems and a systematic rating of each, two were selected for detailed study. These were a flash x-ray system and a dual path acoustical interferometer system which was devised as a result of this project. Although neither system was found to be suitable over the entire range of gun tube geometrics and operational conditions, the dual path acoustical interferometric is recommended as the most suitable system. (Author)

Research paper thumbnail of Techniques for burn wound debridement

The Journal of trauma, 1979

Research paper thumbnail of Electrosurgical treatment of experimental bleeding canine gastric ulcers

Gastroenterology, Mar 1, 1978

for their excellent advice and help with technical problems. Mr. R. D. Wappler of American Cystos... more for their excellent advice and help with technical problems. Mr. R. D. Wappler of American Cystoscope Makers, Inc. and Mr. H. Ichikawa of the Olympus Corporation of America generously provided some equipment for testing.

Research paper thumbnail of Animal endoscopic studies of CO2 assisted argon laser photocoagulation preparatory to controlled trials in man

Gastroenterology, May 1, 1978

Research paper thumbnail of Endoscopic Laser Treatment

Gastroenterology, Sep 1, 1977

The coagulative efficacy of a "high power" argon laser which delivers 6.5 +/- 1.0 w was... more The coagulative efficacy of a "high power" argon laser which delivers 6.5 +/- 1.0 w was compared to that of a "low power" argon laser which delivers 1.0 +/- 0.1 w. The wave-guide angle of divergence was 8 degrees. For the high power laser, the distance between the wave-guide tip and the mucosa varied from 1.0 to 1.5 cm with a delivered power density range of 160 to 487 w per cm2. For the low power laser, the distance between the tip and mucosa varied from 0.7 to 1.3 cm with a power density of 35 to 146 w per cm2. Group A consisted of acute experiments in 6 heparinized dogs in which 51 standard-sized acute gastric ulcers extending into the submucosa were made at laparotomy via a large gastrotomy. Ulcer bleeding rates were quantified into three categories of severity. Within each category, ulcers were randomized to high power, low power, or untreated control. All 19 low power-treated ulcers and 16 untreated controls continued bleeding; 13 of 16 high power-treated ulcers stopped bleeding completely. Representative ulcers were examined histologically. Group B consisted of chronic experiments on 31 ulcers in 7 unheparinized dogs. These ulcers were either treated with high power or left as untreated controls. Dogs were killed and the ulcers were examined histologically at 7, 14, and 28 days. Only rarely did the laser injury penetrate into the muscularis externa. There were no perforations. By 14 days, all lesions were covered with normal surface epithelium. These data encourage further development of congruent to 7.0 w argon laser photocoagulation for eventual clinical use in man.

Research paper thumbnail of High Power Argon Laser Treatment Via Standard Endoscopes

Gastroenterology, Oct 1, 1976

Research paper thumbnail of Laser Photocoagulation for Gastrointestinal Bleeding

Clinics in Gastroenterology, 1978

Endoscopic laser photocoagulation is one of the exciting developments in the field of gastrointes... more Endoscopic laser photocoagulation is one of the exciting developments in the field of gastrointestinal endoscopic therapy. However, much work needs to be done before these techniques should be allowed to proliferate into widespread use. There are few controlled randomized clinical studies evaluating any endoscopic treatment of bleeding, including argon laser and Nd:YAG laser photocoagulation. Despite this, uncontrolled clinical trials of both argon and Nd:YAG laser photocoagulation have begun. Laser photocoagulation of bleeding upper gastrointestinal lesions should be considered a procedure in an experimental stage of development, to be performed only under protocol studies at endoscopic research centres. Only after this or any other haemostatic technique has been proven effective and safe in thorough animal trials and then in controlled clinical trial should it be considered ready for general clinical use.

Research paper thumbnail of Computer modeling and simulation of heat diffusion in tissue with laser and nonlaser sources

The application of laser sources for cutting and coagulation of tissue has enjoyed widespread not... more The application of laser sources for cutting and coagulation of tissue has enjoyed widespread notoriety. Frequently the physician directing laser energy does so with minimal understanding of the response of the tissue to penetrating radiation, the buildup of heat in the tissue, and the propagation of thermal energy during and after the actual laser irradiation. Lengthy animal modeling studies have been performed which have greatly aided the development of good estimates of laser coagulation necrosis when used within tightly confined parameters of space, time, energy, and wavelength. Unfortunatly, much of the enthusiasm which has been showered upon laser coagulation and cutting has occurred because of a generalized fascination with lasers rather than because of some proven character advantage. Older methods of radio-frequency coagulation have experienced a rekindling of interest because of the interest in laser surgery.

Research paper thumbnail of Bipolar electrocoagulation is not safer than unipolar electrocoagulation for stopping bleeding experimental gastric ulcers

Gastroenterology, 1978

The widely held concept of a bipartite autonomie nerveus system has been chällenged in recent yea... more The widely held concept of a bipartite autonomie nerveus system has been chällenged in recent years by the results obtained by electron microscopy. These results showed that, in addition to the cholinergic and adrenergic nerves there is a third type in the autonomie nerveus system. These nerves are found to contain large electron dense granules (800r2000A) as compared with adrenergic nerves which contain smal1 granules (300-500A) and cholinergic nerves which are agranular. During the past few years there has been a great increase in the number of peptides found to be present in both the brsin and gut. Such peptides include vasoactive intestinal peptide (VIP), bombesin, neurotensin, somatostatin, enkephalin and

Research paper thumbnail of The ND: YAG laser is dangerous for photocoagulation of experimental bleeding gastric ulcers when compared with the argon laser

Gastroenterology, 1978

The widely held concept of a bipartite autonomie nerveus system has been chällenged in recent yea... more The widely held concept of a bipartite autonomie nerveus system has been chällenged in recent years by the results obtained by electron microscopy. These results showed that, in addition to the cholinergic and adrenergic nerves there is a third type in the autonomie nerveus system. These nerves are found to contain large electron dense granules (800r2000A) as compared with adrenergic nerves which contain smal1 granules (300-500A) and cholinergic nerves which are agranular. During the past few years there has been a great increase in the number of peptides found to be present in both the brsin and gut. Such peptides include vasoactive intestinal peptide (VIP), bombesin, neurotensin, somatostatin, enkephalin and

Research paper thumbnail of Animal endoscopic studies of CO2 assisted argon laser photocoagulation preparatory to controlled trials in man

Gastroenterology, 1978

Ten comatose patients (age 15 to 93 years: average age 53) were maintained on daily tube alimenta... more Ten comatose patients (age 15 to 93 years: average age 53) were maintained on daily tube alimentation (Ensure, Ross Laboratories, Columbus, Ohio) for a period of six to 60 months (average 32 months). All eight adult patients were able to maintain their body weights and two adolescent patients grew in height and weight as anticipated. Normal values were obtained for skeletal muscle compartment as measured by mid-upper arm circumference (25 cm for two males and 24 cm for eight females) and for fat stores as measured by triceps

Research paper thumbnail of Endoscopic laser treatment

Gastroenterology, 1978

Abstract The purpose of this study is to evaluate the efficacy and safety of a new argon laser sy... more Abstract The purpose of this study is to evaluate the efficacy and safety of a new argon laser system for stopping bleeding from experimental canine gastric ulcers. This system consists of a catheter which can be inserted via an endoscopic biopsy channel to deliver a jet of CO 2 coaxially with an argon laser beam. The efficacy of this system in stopping bleeding was tested in two acute experiments at laparotomy in heparinized dogs using our gastric ulcer model. At 7 w of power the gas-jet-assisted laser proved 100% effective in stopping bleeding with an average of three 5-sec exposures, as compared to the same laser without added CO 2 , which required an average of 11 5-sec exposures. Furthermore, the 7-w laser without added CO 2 did not stop all bleeding ulcers. The safety of the CO 2 laser system was tested in a chronic experiment at sterile laparotomy using the same ulcer model. No ulcer treated with the 7-w gas-jet-assisted argon laser showed histologic evidence of full thickness injury. A final acute experiment compared the efficacy of various wattages of the gas-jet-assisted laser in stopping bleeding from the ulcer model; the wattages used in this series of experiments and in previous experiments proved to be in the efficacious range. We conclude that CO 2 added coaxially to a 6- to 7-w argon laser increases the efficacy of coagulation while reducing the depth of injury.

Research paper thumbnail of Evaluation of electrofulguration in control of bleeding of experimental gastric ulcers

Digestive Diseases and Sciences, 1979

use of a gas more easily ionizable than air allows the generation of a longer spark or generation... more use of a gas more easily ionizable than air allows the generation of a longer spark or generation of a spark using less power. Therefore, in a second series of studies we evaluated the more easily ionizable argon gas to determine if the depth of tissue injury would be reduced.

Research paper thumbnail of Mechanical thrombolysis in acute canine coronary thrombosis

Research paper thumbnail of Mechanical thrombolysis: a new rotational catheter approach for acute thrombi

Circulation, May 1, 1986

We tested a new rotational thrombectomy catheter in acute thrombi formed both in vitro and in viv... more We tested a new rotational thrombectomy catheter in acute thrombi formed both in vitro and in vivo. The catheter consisted of a rounded platinum tip, 0.025 inch diameter by 0.08 inch long, attached to a flexible steel guidewire supported by an external sheath. In vitro, the force required to penetrate thrombus was reduced fivefold by rotation of the catheter at 4000 rpm (0.75 + 1.2 g rotating vs 3.9 ± 2.1 g static; p < .001). Fibrin was extracted selectively from the thrombus and tightly wound about the shaft (3.8 ± 1.5 mg rotating vs 0.75 ± 0.4 mg static; p < .001). In vivo, subtotal or complete thrombosis of the canine femoral artery was created. Thrombectomy by catheter rotation always produced tightly wound adherent fibrin on the catheter shaft. Angiographic patency was restored in 20 of 22 (91%) arteries, totally in seven of 22 (32%) and partially (>20% increase in lumen diameter) in 13 of 22 (59%). There was one arterial perforation (5%). We conclude that this new mechanical catheter device reduces the force required to penetrate thrombus. Additionally, by winding fibrin about its shaft, the catheter is able to selectively remove the fibrin matrix of thrombus. Thus both the ease of initial thrombus recanalization as well as physical removal of thrombus are promoted by this new approach. Such an approach may be relevant to the treatment of recent thrombosis in acute myocardial infarction.

Research paper thumbnail of Bioengineering : Current Status and Future Implications on Clinical Medicine

The Japanese journal of gastro-enterology, Aug 20, 1996

Research paper thumbnail of A Temperature-Compensated, Low-Voltage Regulator

Research paper thumbnail of Laser Photocoagulation Principles

Research paper thumbnail of Flow Capacity, How Much is Enough, Do We Have it, Do We Need More?

Research paper thumbnail of Handpieces for surgical lasers

The use of concentrated laser irradiation for evaporation of tissue has been well accepted. In pa... more The use of concentrated laser irradiation for evaporation of tissue has been well accepted. In particular, the CO2 laser with its very high absorption coefficient permits surface ablation or linear excavation, providing a well controlled surgical device. Its use through the operating microscope enables non-contact management of surgical therapy with unparalleled convenience and precision. However, in other areas of surgery where deeper tissue coagulation is valuable for better hemostasis, the CO2 laser falls short of the clinical need. The use of deeper penetrating laser wavelengths necessarily reduces the superficially evaporative cutting in much the same manner that coagulating waveforms reduce cutting efficienty in electrosurgical scalpels. We have developed a series of transparent quartz scalpel blades which allow delivery of visible and near infrared laser irradiation to a mechanically incised tissue margin resulting in vastly improved hemostasis.The use of concentrated laser irradiation for evaporation of tissue has been well accepted. In particular, the CO2 laser with its very high absorption coefficient permits surface ablation or linear excavation, providing a well controlled surgical device. Its use through the operating microscope enables non-contact management of surgical therapy with unparalleled convenience and precision. However, in other areas of surgery where deeper tissue coagulation is valuable for better hemostasis, the CO2 laser falls short of the clinical need. The use of deeper penetrating laser wavelengths necessarily reduces the superficially evaporative cutting in much the same manner that coagulating waveforms reduce cutting efficienty in electrosurgical scalpels. We have developed a series of transparent quartz scalpel blades which allow delivery of visible and near infrared laser irradiation to a mechanically incised tissue margin resulting in vastly improved hemostasis.

Research paper thumbnail of Gun Tube Bore Strain

Abstract : A study was undertaken to determine the optimum sensing device for measuring the bore ... more Abstract : A study was undertaken to determine the optimum sensing device for measuring the bore strain of a gun tube during rapid firing. The hostile environment that exists within the gun tube and the general operational requirements of the gun tube place severe requirements on any system considered. After consideration of a number of systems and a systematic rating of each, two were selected for detailed study. These were a flash x-ray system and a dual path acoustical interferometer system which was devised as a result of this project. Although neither system was found to be suitable over the entire range of gun tube geometrics and operational conditions, the dual path acoustical interferometric is recommended as the most suitable system. (Author)

Research paper thumbnail of Techniques for burn wound debridement

The Journal of trauma, 1979

Research paper thumbnail of Electrosurgical treatment of experimental bleeding canine gastric ulcers

Gastroenterology, Mar 1, 1978

for their excellent advice and help with technical problems. Mr. R. D. Wappler of American Cystos... more for their excellent advice and help with technical problems. Mr. R. D. Wappler of American Cystoscope Makers, Inc. and Mr. H. Ichikawa of the Olympus Corporation of America generously provided some equipment for testing.

Research paper thumbnail of Animal endoscopic studies of CO2 assisted argon laser photocoagulation preparatory to controlled trials in man

Gastroenterology, May 1, 1978

Research paper thumbnail of Endoscopic Laser Treatment

Gastroenterology, Sep 1, 1977

The coagulative efficacy of a "high power" argon laser which delivers 6.5 +/- 1.0 w was... more The coagulative efficacy of a "high power" argon laser which delivers 6.5 +/- 1.0 w was compared to that of a "low power" argon laser which delivers 1.0 +/- 0.1 w. The wave-guide angle of divergence was 8 degrees. For the high power laser, the distance between the wave-guide tip and the mucosa varied from 1.0 to 1.5 cm with a delivered power density range of 160 to 487 w per cm2. For the low power laser, the distance between the tip and mucosa varied from 0.7 to 1.3 cm with a power density of 35 to 146 w per cm2. Group A consisted of acute experiments in 6 heparinized dogs in which 51 standard-sized acute gastric ulcers extending into the submucosa were made at laparotomy via a large gastrotomy. Ulcer bleeding rates were quantified into three categories of severity. Within each category, ulcers were randomized to high power, low power, or untreated control. All 19 low power-treated ulcers and 16 untreated controls continued bleeding; 13 of 16 high power-treated ulcers stopped bleeding completely. Representative ulcers were examined histologically. Group B consisted of chronic experiments on 31 ulcers in 7 unheparinized dogs. These ulcers were either treated with high power or left as untreated controls. Dogs were killed and the ulcers were examined histologically at 7, 14, and 28 days. Only rarely did the laser injury penetrate into the muscularis externa. There were no perforations. By 14 days, all lesions were covered with normal surface epithelium. These data encourage further development of congruent to 7.0 w argon laser photocoagulation for eventual clinical use in man.

Research paper thumbnail of High Power Argon Laser Treatment Via Standard Endoscopes

Gastroenterology, Oct 1, 1976

Research paper thumbnail of Laser Photocoagulation for Gastrointestinal Bleeding

Clinics in Gastroenterology, 1978

Endoscopic laser photocoagulation is one of the exciting developments in the field of gastrointes... more Endoscopic laser photocoagulation is one of the exciting developments in the field of gastrointestinal endoscopic therapy. However, much work needs to be done before these techniques should be allowed to proliferate into widespread use. There are few controlled randomized clinical studies evaluating any endoscopic treatment of bleeding, including argon laser and Nd:YAG laser photocoagulation. Despite this, uncontrolled clinical trials of both argon and Nd:YAG laser photocoagulation have begun. Laser photocoagulation of bleeding upper gastrointestinal lesions should be considered a procedure in an experimental stage of development, to be performed only under protocol studies at endoscopic research centres. Only after this or any other haemostatic technique has been proven effective and safe in thorough animal trials and then in controlled clinical trial should it be considered ready for general clinical use.

Research paper thumbnail of Computer modeling and simulation of heat diffusion in tissue with laser and nonlaser sources

The application of laser sources for cutting and coagulation of tissue has enjoyed widespread not... more The application of laser sources for cutting and coagulation of tissue has enjoyed widespread notoriety. Frequently the physician directing laser energy does so with minimal understanding of the response of the tissue to penetrating radiation, the buildup of heat in the tissue, and the propagation of thermal energy during and after the actual laser irradiation. Lengthy animal modeling studies have been performed which have greatly aided the development of good estimates of laser coagulation necrosis when used within tightly confined parameters of space, time, energy, and wavelength. Unfortunatly, much of the enthusiasm which has been showered upon laser coagulation and cutting has occurred because of a generalized fascination with lasers rather than because of some proven character advantage. Older methods of radio-frequency coagulation have experienced a rekindling of interest because of the interest in laser surgery.

Research paper thumbnail of Bipolar electrocoagulation is not safer than unipolar electrocoagulation for stopping bleeding experimental gastric ulcers

Gastroenterology, 1978

The widely held concept of a bipartite autonomie nerveus system has been chällenged in recent yea... more The widely held concept of a bipartite autonomie nerveus system has been chällenged in recent years by the results obtained by electron microscopy. These results showed that, in addition to the cholinergic and adrenergic nerves there is a third type in the autonomie nerveus system. These nerves are found to contain large electron dense granules (800r2000A) as compared with adrenergic nerves which contain smal1 granules (300-500A) and cholinergic nerves which are agranular. During the past few years there has been a great increase in the number of peptides found to be present in both the brsin and gut. Such peptides include vasoactive intestinal peptide (VIP), bombesin, neurotensin, somatostatin, enkephalin and

Research paper thumbnail of The ND: YAG laser is dangerous for photocoagulation of experimental bleeding gastric ulcers when compared with the argon laser

Gastroenterology, 1978

The widely held concept of a bipartite autonomie nerveus system has been chällenged in recent yea... more The widely held concept of a bipartite autonomie nerveus system has been chällenged in recent years by the results obtained by electron microscopy. These results showed that, in addition to the cholinergic and adrenergic nerves there is a third type in the autonomie nerveus system. These nerves are found to contain large electron dense granules (800r2000A) as compared with adrenergic nerves which contain smal1 granules (300-500A) and cholinergic nerves which are agranular. During the past few years there has been a great increase in the number of peptides found to be present in both the brsin and gut. Such peptides include vasoactive intestinal peptide (VIP), bombesin, neurotensin, somatostatin, enkephalin and

Research paper thumbnail of Animal endoscopic studies of CO2 assisted argon laser photocoagulation preparatory to controlled trials in man

Gastroenterology, 1978

Ten comatose patients (age 15 to 93 years: average age 53) were maintained on daily tube alimenta... more Ten comatose patients (age 15 to 93 years: average age 53) were maintained on daily tube alimentation (Ensure, Ross Laboratories, Columbus, Ohio) for a period of six to 60 months (average 32 months). All eight adult patients were able to maintain their body weights and two adolescent patients grew in height and weight as anticipated. Normal values were obtained for skeletal muscle compartment as measured by mid-upper arm circumference (25 cm for two males and 24 cm for eight females) and for fat stores as measured by triceps

Research paper thumbnail of Endoscopic laser treatment

Gastroenterology, 1978

Abstract The purpose of this study is to evaluate the efficacy and safety of a new argon laser sy... more Abstract The purpose of this study is to evaluate the efficacy and safety of a new argon laser system for stopping bleeding from experimental canine gastric ulcers. This system consists of a catheter which can be inserted via an endoscopic biopsy channel to deliver a jet of CO 2 coaxially with an argon laser beam. The efficacy of this system in stopping bleeding was tested in two acute experiments at laparotomy in heparinized dogs using our gastric ulcer model. At 7 w of power the gas-jet-assisted laser proved 100% effective in stopping bleeding with an average of three 5-sec exposures, as compared to the same laser without added CO 2 , which required an average of 11 5-sec exposures. Furthermore, the 7-w laser without added CO 2 did not stop all bleeding ulcers. The safety of the CO 2 laser system was tested in a chronic experiment at sterile laparotomy using the same ulcer model. No ulcer treated with the 7-w gas-jet-assisted argon laser showed histologic evidence of full thickness injury. A final acute experiment compared the efficacy of various wattages of the gas-jet-assisted laser in stopping bleeding from the ulcer model; the wattages used in this series of experiments and in previous experiments proved to be in the efficacious range. We conclude that CO 2 added coaxially to a 6- to 7-w argon laser increases the efficacy of coagulation while reducing the depth of injury.

Research paper thumbnail of Evaluation of electrofulguration in control of bleeding of experimental gastric ulcers

Digestive Diseases and Sciences, 1979

use of a gas more easily ionizable than air allows the generation of a longer spark or generation... more use of a gas more easily ionizable than air allows the generation of a longer spark or generation of a spark using less power. Therefore, in a second series of studies we evaluated the more easily ionizable argon gas to determine if the depth of tissue injury would be reduced.

Research paper thumbnail of Mechanical thrombolysis in acute canine coronary thrombosis

Research paper thumbnail of Mechanical thrombolysis: a new rotational catheter approach for acute thrombi

Circulation, May 1, 1986

We tested a new rotational thrombectomy catheter in acute thrombi formed both in vitro and in viv... more We tested a new rotational thrombectomy catheter in acute thrombi formed both in vitro and in vivo. The catheter consisted of a rounded platinum tip, 0.025 inch diameter by 0.08 inch long, attached to a flexible steel guidewire supported by an external sheath. In vitro, the force required to penetrate thrombus was reduced fivefold by rotation of the catheter at 4000 rpm (0.75 + 1.2 g rotating vs 3.9 ± 2.1 g static; p < .001). Fibrin was extracted selectively from the thrombus and tightly wound about the shaft (3.8 ± 1.5 mg rotating vs 0.75 ± 0.4 mg static; p < .001). In vivo, subtotal or complete thrombosis of the canine femoral artery was created. Thrombectomy by catheter rotation always produced tightly wound adherent fibrin on the catheter shaft. Angiographic patency was restored in 20 of 22 (91%) arteries, totally in seven of 22 (32%) and partially (>20% increase in lumen diameter) in 13 of 22 (59%). There was one arterial perforation (5%). We conclude that this new mechanical catheter device reduces the force required to penetrate thrombus. Additionally, by winding fibrin about its shaft, the catheter is able to selectively remove the fibrin matrix of thrombus. Thus both the ease of initial thrombus recanalization as well as physical removal of thrombus are promoted by this new approach. Such an approach may be relevant to the treatment of recent thrombosis in acute myocardial infarction.