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High Definition Optical System for Microsurgical Heterotopic Heart Transplantation in Rats
High Definition Optical System for Microsurgical Heterotopic Heart Transplantation in Rats R. Vespignani, A. Ruzza, L.S.C. Czer, G. Berci, and A. Trento ABSTRACT Background. Clinical and experimental cardiovascular surgery as well as other surgical disciplines may require visualization and manipulation of small anatomic structures. A high-definition optical system was developed for magnification and illumination as an alternative to surgical loupes or a traditional operating microscope. Materials and Methods. A video telescopic optical imaging system that provided a high-definition and magnification of the surgical field was used for visualization of small anatomic structures and as an aid to the performance of small vessel anastomoses in a series of 10 heterotopic heart transplants (HHTx) in rats. Results. The video telescopic optical system was easy to manipulate and comfortable to use, and provided high-definition images for magnification of anatomic structures while performing microvascular cardiac surgery in a small animal model of HHTx in rats. Fatigue and neck problems for the surgeon were reduced. Conclusions. The video telescopic imaging system provided high definition and magnification of the surgical field, and was used for visualization of small anatomic structures and as an aid to the performance of small vessel anastomoses. The system is an alternative to surgical loupes or a traditional operating microscope, and was used for the first time in microvascular cardiac surgery in a rat HHTx model. EDIATRIC AND adult cardiac surgeons as well as surgeons in other disciplines may require visualization and manipulation of small anatomic structures during clinical or experimental surgery. Heterotopic heart transplantation (HHTx) in rodents is an important and valuable model for studying graft vasculopathy, evaluating new immunosuppressive strategies, and to understand the mechanisms of rejection and tolerance.1– 6 In rodents, cardiac surgery requires magnification of the operating field owing to the small size of the heart and blood vessels. We report the first use of a new high-definition magnification and viewing system for application in cardiac microsurgery in small animals as an alternative to the surgical loupes or the standard operating microscope.
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MATERIALS AND METHODS The high-definition video imaging system consists (Fig 1) of an autoclavable rigid lens telescope (HDXO-SCOPE, Karl Storz Endoscopy, Tuttlingen, Germany) with a 300-W xenon fiber optic light source (Xenon Nova 300; Karl Storz) attached directly to the telescope and a 3-chip sterilizable high definition digitized camera (A3, Karl Storz). The system is held in position by a mechanical
arm holder (Point Setter; Mitaka Kohki Co, Tokyo, Japan) with a wide range of motion. We performed a series of 10 HHTx in rats4 – 6 using the highdefinition video imaging system in accordance with the principles of laboratory animal care and guide for care and use of laboratory animals prepared and formulated by the Institute of Laboratory Animal Resources, published by the National Institute of Health, and previously approved by our institutional animal care and utilization committee. Anesthesia was initiated by placing the animals in a small induction chamber with 5% isoflurane and 2% oxygen and maintenance by using an anesthetic machine (HME109 TableTop Unit, Highland Medical Equipment, Temecula, Calif) with a rodent nose cone delivering 2%–3% isoflurane and 1%
From the Divisions of Cardiothoracic Surgery (R.V., A.R., A.T.), and Cardiology, (L.S.C.C.), Cedars Sinai-Heart Institute, and the Department of Surgery, (G.B.), Cedars-Sinai Medical Center, Los Angeles, California, USA. Address correspondence to Lawrence S.C. Czer, MD, Medical Director, Heart Transplant Program, Cedars-Sinai Heart Institute, Cedars-Sinai Medical Center, 8700 Beverly Blvd, Los Angeles, CA 90048. E-mail: [email protected]
0041-1345/12/$–see front matter http://dx.doi.org/10.1016/j.transproceed.2012.01.119
© 2012 by Elsevier Inc. All rights reserved. 360 Park Avenue South, New York, NY 10010-1710
1404
Transplantation Proceedings, 44, 1404 –1406 (2012)
HD OPTICAL SYSTEM FOR MICRO SURGERY
1405
Fig 1. Left (A) The video telescopic imaging system, comprised of a full high-definition (HD) camera, (B) optical system, and (C) dual illuminator. The entire unit can be sterilized. This optical system can record full HD photos and/or HD videos. (Right). The image is seen on a 26-inch HD monitor and observed from a convenient distance and angle. There is much less fatigue than using a loupe or the operating microscope. oxygen. Effective scavenging of waste gases was provided by a modified Ayers nonrebreathing system. The rat’s suprarenal abdominal aorta (Fig 2) was the most suitable place to start the anastomoses of the ascending aorta and pulmonary artery of the harvested donor heart to the abdominal aorta and the inferior vena cava of the recipient rat, respectively. The anastomoses were performed as described previously.4 – 6
RESULTS
The video imaging system produced high-quality video images with a wide field of view and a mean object distance of 20 cm. There was minimal spherical aberration or chromatic distortion, a wide viewing angle, a mean focal distance of 200 mm, a 12-mm depth of field without need for refocusing, and a magnification of 2–16⫻. The large focal distance permitted the passage of instruments and was more compact and easier to manipulate than the standard operating microscope. The images permitted visualization of the anatomic structures and instruments while looking
Fig 2. Heterotopic heart transplant model in the rat. Asc Ao, ascending aorta; Distal Abd Ao, distal abdominal aorta; IVC, inferior vena cava; PA, pulmonary artery; LRV, left renal vein; RRA, renal artery.
either at the 26-inch high-definition monitor of the field or while observing directly the surgical field itself.7 Surgical procedures were carried out by visualizing the anatomy displayed to high-definition monitor with the surgeon in a sitting or standing position. We found that the video telescopic imaging system provided better image resolution, quality, and magnification than the standard operating microscope even at high magnification. Utilization of this system provided also an excellent illumination for procedures, which was greater than the halogen light source of the operating microscope. The video telescopic imaging system had an excellent depth of field, with stereoscopic-like perception, reducing the need for repeated focusing, which was required with the standard operating microscope. The video telescopic imaging system was very light and easy to manipulate—weighing only 0.7 kg— compared with the 100 kg of the traditional microscope. The magnified image on the monitor could be observed from a convenient distance without fatigue and the enlarged image quality was superb. Using the loupe produced a 2.5–3.5⫻ magnification and the larger types of magnification were too heavy and needed continuous focusing by moving the head. This resulted in fatigue or neck problems for the surgeon. The same occurred with the standard operating microscope because of the requirement to look through a small angulated pupil for hours in a fixed and uncomfortable position. Long-term survival (⬎11 months) in the rat HHTx model was achieved in 9 of the 10 animals. All 9 animals had palpable beating hearts while alive and at sacrifice had functioning heterografts. One animal died several months after the surgery for undefined reason. The success of HHTx in the small animal depends on several factors, such as anesthetic management, surgical technique, and microsurgical skills of the surgeon and size
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appropriate surgical instruments.5 Other important aspects of the procedure are the availability of loupes with up to 6-fold magnification or an operating viewing system with up to 40-fold magnification, suitable micro-instruments, and thin monofilament sutures (10 – 0, 11– 0).4 – 6 After use of the high-definition video telescopic imaging system in large animal neurosurgical procedures, a clinical trial to test its use for human neurosurgery is underway.8,9 Microsurgical techniques are fundamental to research studies that involve small animals, and the high definition video telescopic imaging system may aid performance of routine microsurgical procedures. In conclusion, we report the first use of a high-definition video telescopic imaging system in a cardiac microsurgical model of heterotopic heart transplantation in a small animal (rat) model. The video telescopic imaging system was easy to use, provided high-resolution images of the surgical field with excellent magnification and illumination, and allowed surgical manipulation of anatomic structures in small animals while permitting a comfortable position for the surgeon with minimal fatigue and neck discomfort. The HHTx procedure in rats resulted in excellent long-term survival (⬎11 months). The high-definition video telescopic imaging system is well suited to microsurgical procedures in animals and may find application in humans.
VESPIGNANI, RUZZA, CZER ET AL
REFERENCES 1. Ono K, Lindsey ES: Improved technique of heart transplantation in rats. J Thorac Cardiovasc Surg 57:225, 1969 2. Ono K, Lindsey ES, Creech O Jr: Transplanted rat heart: local graft irradiation. Transplantation 7:176, 1969 3. Adams DH, Tilney NL, Collins JJ Jr, et al: Experimental graft arteriosclerosis. I. The Lewis-to-F-344 allograft model. Transplantation 53:1115, 1992 4. Soukiasian HJ, Czer LS, Wang HM, et al: Inhibition of graft coronary arteriosclerosis after heart transplantation. Am Surg 70:833, 2004 5. Ruzza A, Vespignani R, Czer LS, et al: Heterotopic heart transplantation in rats: improved anesthetic and surgical technique. Transplant Proc 42:3828, 2010 6. Czer LS, Wong AV, Soukiasian HJ, et al: Prolonged ischemic times and less donor-recipient histocompatibility accelerate graft vascular disease. Transplant Proc 43:3863, 2011 7. Yamauchi Y, Shinohara K: Effect of binocular stereopsis on surgical manipulation performance and fatigue when using a stereoscopic endoscope. Stud Health Techno Inform 111:614, 2005 8. Mamelak AN, Danielpour M, Black KL, et al: A highdefinition exoscope system for neurosurgery and other microsurgical disciplines: preliminary report. Surg Innov 15:38, 2008 9. Mamelak AN, Nobuto T, Berci G: Initial clinical experience with a high-definition exoscope system for microneurosurgery. Neurosurgery 67:476, 2010
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MATERIALS AND METHODS The high-definition video imaging system consists (Fig 1) of an autoclavable rigid lens telescope (HDXO-SCOPE, Karl Storz Endoscopy, Tuttlingen, Germany) with a 300-W xenon fiber optic light source (Xenon Nova 300; Karl Storz) attached directly to the telescope and a 3-chip sterilizable high definition digitized camera (A3, Karl Storz). The system is held in position by a mechanical
arm holder (Point Setter; Mitaka Kohki Co, Tokyo, Japan) with a wide range of motion. We performed a series of 10 HHTx in rats4 – 6 using the highdefinition video imaging system in accordance with the principles of laboratory animal care and guide for care and use of laboratory animals prepared and formulated by the Institute of Laboratory Animal Resources, published by the National Institute of Health, and previously approved by our institutional animal care and utilization committee. Anesthesia was initiated by placing the animals in a small induction chamber with 5% isoflurane and 2% oxygen and maintenance by using an anesthetic machine (HME109 TableTop Unit, Highland Medical Equipment, Temecula, Calif) with a rodent nose cone delivering 2%–3% isoflurane and 1%
From the Divisions of Cardiothoracic Surgery (R.V., A.R., A.T.), and Cardiology, (L.S.C.C.), Cedars Sinai-Heart Institute, and the Department of Surgery, (G.B.), Cedars-Sinai Medical Center, Los Angeles, California, USA. Address correspondence to Lawrence S.C. Czer, MD, Medical Director, Heart Transplant Program, Cedars-Sinai Heart Institute, Cedars-Sinai Medical Center, 8700 Beverly Blvd, Los Angeles, CA 90048. E-mail: [email protected]
0041-1345/12/$–see front matter http://dx.doi.org/10.1016/j.transproceed.2012.01.119
© 2012 by Elsevier Inc. All rights reserved. 360 Park Avenue South, New York, NY 10010-1710
1404
Transplantation Proceedings, 44, 1404 –1406 (2012)
HD OPTICAL SYSTEM FOR MICRO SURGERY
1405
Fig 1. Left (A) The video telescopic imaging system, comprised of a full high-definition (HD) camera, (B) optical system, and (C) dual illuminator. The entire unit can be sterilized. This optical system can record full HD photos and/or HD videos. (Right). The image is seen on a 26-inch HD monitor and observed from a convenient distance and angle. There is much less fatigue than using a loupe or the operating microscope. oxygen. Effective scavenging of waste gases was provided by a modified Ayers nonrebreathing system. The rat’s suprarenal abdominal aorta (Fig 2) was the most suitable place to start the anastomoses of the ascending aorta and pulmonary artery of the harvested donor heart to the abdominal aorta and the inferior vena cava of the recipient rat, respectively. The anastomoses were performed as described previously.4 – 6
RESULTS
The video imaging system produced high-quality video images with a wide field of view and a mean object distance of 20 cm. There was minimal spherical aberration or chromatic distortion, a wide viewing angle, a mean focal distance of 200 mm, a 12-mm depth of field without need for refocusing, and a magnification of 2–16⫻. The large focal distance permitted the passage of instruments and was more compact and easier to manipulate than the standard operating microscope. The images permitted visualization of the anatomic structures and instruments while looking
Fig 2. Heterotopic heart transplant model in the rat. Asc Ao, ascending aorta; Distal Abd Ao, distal abdominal aorta; IVC, inferior vena cava; PA, pulmonary artery; LRV, left renal vein; RRA, renal artery.
either at the 26-inch high-definition monitor of the field or while observing directly the surgical field itself.7 Surgical procedures were carried out by visualizing the anatomy displayed to high-definition monitor with the surgeon in a sitting or standing position. We found that the video telescopic imaging system provided better image resolution, quality, and magnification than the standard operating microscope even at high magnification. Utilization of this system provided also an excellent illumination for procedures, which was greater than the halogen light source of the operating microscope. The video telescopic imaging system had an excellent depth of field, with stereoscopic-like perception, reducing the need for repeated focusing, which was required with the standard operating microscope. The video telescopic imaging system was very light and easy to manipulate—weighing only 0.7 kg— compared with the 100 kg of the traditional microscope. The magnified image on the monitor could be observed from a convenient distance without fatigue and the enlarged image quality was superb. Using the loupe produced a 2.5–3.5⫻ magnification and the larger types of magnification were too heavy and needed continuous focusing by moving the head. This resulted in fatigue or neck problems for the surgeon. The same occurred with the standard operating microscope because of the requirement to look through a small angulated pupil for hours in a fixed and uncomfortable position. Long-term survival (⬎11 months) in the rat HHTx model was achieved in 9 of the 10 animals. All 9 animals had palpable beating hearts while alive and at sacrifice had functioning heterografts. One animal died several months after the surgery for undefined reason. The success of HHTx in the small animal depends on several factors, such as anesthetic management, surgical technique, and microsurgical skills of the surgeon and size
1406
appropriate surgical instruments.5 Other important aspects of the procedure are the availability of loupes with up to 6-fold magnification or an operating viewing system with up to 40-fold magnification, suitable micro-instruments, and thin monofilament sutures (10 – 0, 11– 0).4 – 6 After use of the high-definition video telescopic imaging system in large animal neurosurgical procedures, a clinical trial to test its use for human neurosurgery is underway.8,9 Microsurgical techniques are fundamental to research studies that involve small animals, and the high definition video telescopic imaging system may aid performance of routine microsurgical procedures. In conclusion, we report the first use of a high-definition video telescopic imaging system in a cardiac microsurgical model of heterotopic heart transplantation in a small animal (rat) model. The video telescopic imaging system was easy to use, provided high-resolution images of the surgical field with excellent magnification and illumination, and allowed surgical manipulation of anatomic structures in small animals while permitting a comfortable position for the surgeon with minimal fatigue and neck discomfort. The HHTx procedure in rats resulted in excellent long-term survival (⬎11 months). The high-definition video telescopic imaging system is well suited to microsurgical procedures in animals and may find application in humans.
VESPIGNANI, RUZZA, CZER ET AL
REFERENCES 1. Ono K, Lindsey ES: Improved technique of heart transplantation in rats. J Thorac Cardiovasc Surg 57:225, 1969 2. Ono K, Lindsey ES, Creech O Jr: Transplanted rat heart: local graft irradiation. Transplantation 7:176, 1969 3. Adams DH, Tilney NL, Collins JJ Jr, et al: Experimental graft arteriosclerosis. I. The Lewis-to-F-344 allograft model. Transplantation 53:1115, 1992 4. Soukiasian HJ, Czer LS, Wang HM, et al: Inhibition of graft coronary arteriosclerosis after heart transplantation. Am Surg 70:833, 2004 5. Ruzza A, Vespignani R, Czer LS, et al: Heterotopic heart transplantation in rats: improved anesthetic and surgical technique. Transplant Proc 42:3828, 2010 6. Czer LS, Wong AV, Soukiasian HJ, et al: Prolonged ischemic times and less donor-recipient histocompatibility accelerate graft vascular disease. Transplant Proc 43:3863, 2011 7. Yamauchi Y, Shinohara K: Effect of binocular stereopsis on surgical manipulation performance and fatigue when using a stereoscopic endoscope. Stud Health Techno Inform 111:614, 2005 8. Mamelak AN, Danielpour M, Black KL, et al: A highdefinition exoscope system for neurosurgery and other microsurgical disciplines: preliminary report. Surg Innov 15:38, 2008 9. Mamelak AN, Nobuto T, Berci G: Initial clinical experience with a high-definition exoscope system for microneurosurgery. Neurosurgery 67:476, 2010