Biomedical subjects
Publications and source records attributed to Alan P Kypson.
Evolving technologies have resulted in an increase in minimally invasive cardiac surgery. Currently, robotic systems allow surgeons to perform a variety of procedures through small incisions. This changing paradigm is reviewed.
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Cardiovascular surgery has traditionally been performed through a median sternotomy, allowing the surgeon generous access to the heart and surrounding great vessels. Recently, less invasive methods have been developed to allow the surgeon the same amount of dexterity and accessibility to the heart, thus resulting in a paradigm shift in cardiac surgery. Originally, long instruments without pivot points were used, however; with the application of robotic telemanipulation systems that allow for improved dexterity, the surgeon is able to perform cardiac surgery from a distance not previously possible. In this rapidly evolving field, this article reviews the recent history and clinical results of robotics in cardiovascular surgery.
PURPOSE: Robotic mitral valve repair increases precision however operative times are longer. Prior studies have indicated that robotic knot tying is time consuming and it is without potential room for improvement. We therefore investigated tissue approximation devices that may shorten operative times. DESCRIPTION: A 67-year-old female was approached through a right mini-thoracotomy with the da Vinci Robotic Surgical System (Intuitive Surgical, Sunnyvale, CA). Using 12 nitinol U-clips (Coalescent Surgical, Sunnyvale, CA) an annuloplasty band was placed under robotic guidance. Clip placement and deployment times were recorded and statistical comparisons were assessed to prior suture annuloplasties. EVALUATION: Clip placement time was 1.3 +/- 0.9 (minutes +/- standard deviation), statistical comparison with first, most recent, and all prior suture annuloplasties proving no significance. Clip deployment time was 0.5 +/- 0.2, whereas knot-tying times and respective statistical comparison for first, most recent, and all prior suture annuloplasties were 2.0 +/- 0.7 (p = 0.003), 1.2 +/- 0.4 (p = 0.0004), and 1.6 +/- 0.6 (p < 0.00001). Follow-up echocardiography performed postoperatively, at 3 months, and at 9 months revealed valvular structural integrity with only minimal mitral regurgitation. CONCLUSIONS: U-clips considerably reduce time for annuloplasty over conventional suture and may help reduce operative times as well.
BACKGROUND: Left atrial microwave ablation for atrial fibrillation has become popular for isolating autonomous atrial foci. Previously, mitral valve repairs (MVP) with atrial fibrillation ablation have been performed through sternotomy. We present a technique that combines robotic MVP with left atrial fibrillation ablation. METHODS: Through a 4-cm right minithoracotomy and using cardiopulmonary bypass, the transverse and oblique sinuses are accessed. A Flex-10 microwave catheter is passed around the pulmonary veins, and after weaning from cardiopulmonary bypass, peripulmonary vein microwave ablations are performed. After cardioplegic arrest, the da Vinci system is used to manipulate the catheter to create endocardial lesions around the left atrial appendage. Another endocardial lesion is made connecting the pulmonary venous line with the mitral annulus near P3. The left atrial appendage is closed, and the MVP performed robotically. Data are expressed as mean +/- standard deviation. RESULTS: Sixteen patients underwent this combined procedure, with 80% returning to a normal sinus rhythm at 6 weeks and 73% remaining in normal sinus rhythm at 6 months. Only 1 patient was in atrial fibrillation at 6 months. The ablation procedure added 42 +/- 16.1 minutes to a robotic MVP. The average length of hospital stay was 6.3 +/- 2.2 days, 1.3 days longer than the mean of the prior 50 consecutive robotic MVP patients without a concomitant ablation. CONCLUSIONS: Robotic microwave ablation during robotic MVP is a safe, effective way to resolve atrial fibrillation. These methods offer a promising prelude to the combined totally endoscopic treatment of atrial arrhythmias and mitral insufficiency.
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OBJECTIVES: In minimally invasive and robotic mitral valve surgery, a blade retractor is used to elevate the left atrial roof, which often distorts tissue and impairs visualization. We tested the hemodynamic and histologic changes of intra-atrial suction, using a new suction retractor that may improve stabilization and visualization. METHODS: Swine were divided into 3 equal (n = 4) groups: blade retractor, suction retractor, and arrested heart control. Left atrial ultrasonic crystals were used to record ejection fractions. After cardioplegic arrest, the atrium was opened and sampled for preretractor histology. Retractors remained in place for 1 hour, followed by postretractor histologic sampling. Controls were crossclamped for an equivalent time and postarrest histologic data obtained. Animals were weaned from bypass, data were collected for 4 hours, and postsacrifice atrial histologic samples were obtained. RESULTS: The main effect due to treatment was not statistically significant ( P = .52) between the 3 groups, with the 4-hour average ejection fraction for blade retractor, suction retractor, and control being statistically equivalent at 33.3% +/- 8.3, 35.3% +/- 12.1, and 40.8% +/- 9.9 (mean +/- standard deviation), respectively. Histology showed equivalent amounts of myocyte fragmentation, interstitial edema, eosinophilia, and wavy fibers between blade retraction and suction retraction, while the latter showed slightly increased amounts of hemorrhage. CONCLUSIONS: Atrial endocardial suction retraction appears to be safe with no acute changes in the left atrial ejection fraction or significant acute histologic differences, compared to blade retraction. Furthermore, intra-atrial suction may be applicable to procedures other than minimally invasive and robotic mitral valve repair for providing improved stabilization.
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Historically, contraindications to minimally invasive or robotic mitral valve surgery have included prior mastectomy, thoracic reconstruction, or chest radiation. However, we believe that by granting flexibility in the choice of skin incision site while performing careful dissection, surgeons can provide these patients the outstanding results afforded by a minithoracotomy. We present a patient who had undergone a prior mastectomy and radiation treatment in whom we performed a minimally invasive mitral valve repair through a right-sided minithoracotomy using the previous mastectomy incision.
Historically, patients with prior aortic valve replacements who subsequently present with an ascending aortic aneurysm require placement of a valve conduit. However, if the patient has a functional mechanical valve with proven long-term durability, an attempt can be made to preserve the intact valve and to graft the aneurysmal aortic root. The case is described of a patient with a previously placed Starr-Edwards aortic valve who subsequently developed a 6-cm ascending aortic aneurysm. By removing the valve ball and using the existing sewing ring, a proximal graft anastomosis was created with ease, eliminating valve excision.
Over the last decade, significant technological advancements have occurred in cardiac surgery. One such breakthrough has been the use of robotic telemanipulation systems, which allow the surgeon to perform cardiac surgery through a minimally invasive approach. As a result, surgery for atrial fibrillation and resynchronization therapy for congestive heart failure have been increasingly incorporated into the surgeon's armamentarium.
Currently, cardiac surgery is an evolving field. Not only has there been a technological explosion, but there also is a strong interest in minimally invasive operations. Mitral valve surgery can now be performed with the use of sophisticated robotic systems through small incisions. The patient of today and the future will demand minimally invasive operations. Initial clinical experience with robotic systems will allow for further developments that, ultimately, may result in completely endoscopic heart surgery. In this rapidly evolving field, we review the recent history and clinical results of robotically assisted mitral valve surgery at our institution.
BACKGROUND: The advantages of internal thoracic artery skeletonization include early high blood flow, a longer conduit, and less bleeding than pedicle internal thoracic artery grafts. Longer conduits are needed for complete endoscopic arterial revascularization. Therefore this study was designed to determine the feasibility and safety of internal thoracic artery skeletonization using the da Vinci robotic system (Intuitive Surgical, Sunnyvale, CA). METHODS: Nine dogs underwent bilateral robotic internal thoracic artery harvesting through three ports placed in the left chest. One internal thoracic artery was harvested as a pedicle in each dog, and the other was skeletonized. Internal thoracic artery blood flow was measured in each graft, and comparative endothelial histologic studies were performed. Data are mean +/- the standard error of the mean. RESULTS: All 18 internal thoracic arteries were harvested successfully. Skeletonized internal thoracic artery harvests required more time (48.0 minutes +/- 1.8) than pedicle internal thoracic artery harvests (39.0 minutes +/- 1.4; p < 0.05). Internal thoracic artery flows during the final intervals were similar (skeletonized = 30.0 mL/min +/- 2.4 vs pedicle = 31.5 mL/min +/- 1.8; p = 0.9). Free internal thoracic artery bleeding flow was similar in both groups (skeletonized = 162.0 mL/min +/- 3.0 vs pedicle = 189.0 mL/min +/- 2.4; p = 0.4). Histologically, both groups were similar with minimal endothelial damage. CONCLUSIONS: Robotically skeletonized harvesting is safe, but it requires more time (48.0 minutes +/- 1.8) than pedicle internal thoracic artery harvesting. Despite muted tactile feedback with robotics, neither technique was associated with histologic or functional damage. These encouraging results may represent an advantage for complete arterial revascularization in robotic coronary bypass patients.
A combined robotic-assisted left atrial ablation and mitral valve repair was done through a 5-cm right anterior mini-thoracotomy. The patient was a 54-year-old man with severe mitral regurgitation and a 10-month history of persistent atrial fibrillation. The patient underwent off-pump, beating heart epicardial peripulmonary vein microwave ablation using the FLEX 10 catheter (AFx Inc, Fremont, CA), followed by supplemental on-pump endocardial lesions. The procedure was done using the da Vinci surgical robot (Intuitive Surgical Inc, Sunnyvale, CA). The mitral valve repair consisted of a No. 38 Cosgrove annuloplasty band implantation (Edwards Life Sciences, LLC, Irvine, CA). The postoperative recovery was uneventful, and the patient maintained normal sinus rhythm.
PURPOSE OF REVIEW: Currently, cardiac surgery is an evolving field. Not only has there been a technologic explosion, but there is also a strong interest in minimally invasive operations. Mitral valve surgery can now be performed with the use of sophisticated robotic systems through small incisions, and a review of recent advances is warranted. RECENT FINDINGS: Various groups have now documented that robotic valve surgery is feasible and safe. Despite an initial learning curve, facility with the procedure is gained with increasing experience. SUMMARY: Robotic mitral valve surgery is a procedure that is gaining widespread popularity. The patient of today and the future will demand minimally invasive operations. Initial clinical experience with robotic systems will allow further developments. Ultimately, this may result in completely endoscopic heart surgery.
BACKGROUND AND AIM OF THE STUDY: Reoperative cardiac surgery carries a greater morbidity and mortality than primary cardiac surgery. The study aim was to compare perioperative outcomes in patients undergoing mitral valve surgery who had already undergone a previous cardiac operation using either a minimally invasive video-assisted (MIVA) mini-thoracotomy or a redo median sternotomy (MS). METHODS: Between January 1996 and June 2003, 71 consecutive patients with prior cardiac surgery underwent mitral valve surgery. Of these operations, 38 were MIVA procedures, performed through a 5-cm right anterior thoracotomy using voice-activated robotic camera control (AESOP 3000). Outcome was compared with results in 33 consecutive patients who underwent a standard redo MS. RESULTS: The MIVA and redo MS cohorts differed in preoperative ejection fraction (46 +/- 2% versus 55 +/- 2%; p = 0.004) and percentage of urgent operations (33 versus 8.3%; p = 0.01). Operative mortality was similar in both groups (5.7% and 5.9% respectively; p = 0.976), as were cardiopulmonary bypass, operating room, and ICU times. Postoperative intubation time was shorter in the MIVA group than in the redo MS group (29.1 +/- 8.9 versus 38.0 +/- 9.9 h; p = 0.008), and blood transfusion requirements were also reduced (2.9 +/- 0.6 versus 5.5 +/- 0.7 units; p = 0.001) respectively. Length of hospital stay was significantly less in the MIVA group (7.1 +/- 1.3 versus 11.2 +/- 1.1 days; p = 0.001). CONCLUSION: Minimally invasive video-assisted mitral valve operations may be performed safely and efficiently in patients with prior cardiac surgery. Demonstrated advantages include fewer red blood cell and blood product transfusions, as well as decreased intubation time and length of hospital stay.
The rare finding of heterotopic ossification in a case of primary rectal adenocarcinoma is described along with a review of the literature. Immunohistochemistry for a bone morphogenic protein (BMP-2) and fibroblast growth factor (FGF-2), both of which induce and stimulate bone formation, was performed and revealed overexpression of BMP-2 by the tumor cells, elucidating a possible mechanism which up to now had been based merely on speculation.
Paroxysmal cold hemoglobinuria, a cold-reactive autoimmune disease associated with the Donath-Landsteiner antibody, has not been described in patients undergoing cardiac surgery. We report a case of mitral valve replacement in a woman with a positive Donath-Landsteiner antibody and a history of recurrent hemolysis and hemoglobinuria secondary to cold exposure. Successful perioperative management is described, as is a discussion of paroxysmal cold hemoglobinuria.