Robotics in cardiac surgery.

Minimally invasive surgery has revolutionized the surgical field over the last two decades. Robotic assisted surgery is the latest iteration towards less invasive techniques. Cardiac surgeons have slowly adapted minimally invasive and robotics techniques into their armamentarium. In particular, minimally invasive mitral valve surgery has evolved over the last decade and become the preferred method of mitral valve repair and replacement at certain specialized centres worldwide because of excellent results. We have developed a robotic mitral valve surgery program which utilizes the da Vinci telemanipulation system allowing the surgeon to perform complex mitral valve repairs through 5mm port sites rather than a traditional median sternotomy. In this rapidly evolving field, we review the evolution and clinical results of robotically-assisted mitral valve surgery and take a look at the other cardiac surgical procedures for which da Vinci is currently being used.

Thoracoscopic robot-assisted bronchoplasty.

BACKGROUND: In robotic surgery, the ideal position of the system, as well as the optimal working angles and the proper positioning of the thoraco ports position is very important. No robot-assisted bronchoplasty has been reported. Our study describes use of the da VinciTM surgical system (Intuitive Surgical, Inc.) for robotic sleeve upper lobectomy in a human fresh cadaver. METHODS: A male cadaver was placed in the left lateral decubitus position. After thoracoscopic upper lobectomy was performed through the working port and the two ports, the robotic system was then set up behind the cadaver. The working port allowed introduction of the optical scope and the robotic surgical arms were inserted into the thoraco ports. The right bronchus was dissected and wedge was cut out with the robotic scissors. After standard lymph node dissection, end-to-end bronchial anastomosis was performed with robotic instruments. Once the anastomosis was complete, air leakage was checked with saline solution placed in the pleural cavity. RESULTS: Thoracoscopic robot-assisted bronchoplasty was performed successfully. CONCLUSIONS: In evaluating various positions of the system we demonstrated that our technique is sufficient approaches to robotic bronchoplasty. This procedure offers specific advantages over conventional bronchoplasty with accuracy and safety.

Robotic mitral valve surgery: a United States multicenter trial.

OBJECTIVE: In a prospective phase II Food and Drug Administration trial, robotic mitral valve repairs were performed in 112 patients at 10 centers by using the da Vinci surgical system. The safety of performing valve repairs with computerized telemanipulation was studied. METHODS: After institutional review board approval, informed consent was obtained. Patients had moderate to severe mitral regurgitation. Operative technique included peripheral cardiopulmonary bypass, a 4- to 5-cm right minithoracotomy, a transthoracic aortic crossclamp, and antegrade cardioplegia. The successful study end point was grade 0 or 1 mitral regurgitation by transthoracic echocardiography at 1 month after surgery. RESULTS: Valve repairs included quadrangular resections, sliding plasties, edge-to-edge approximations, and both chordal transfers and replacements. The average age was 56.4 +/- 0.09 years (mean +/- SEM). There were 77 (68.8%) men and 35 (31.2%) women. Valve pathology was myxomatous degeneration in 105 (91.1%), and 103 (92.0%) had type II leaflet prolapse. Leaflet repair times averaged 36.7 +/- 0.2 minutes, with annuloplasty times of 39.6 +/- 0.1 minutes. Total robot, aortic crossclamp, and cardiopulmonary bypass times were 77.9 +/- 0.3 minutes, 2.1 +/- 0.1 hours, and 2.8 +/- 0.1 hours, respectively. On 1-month transthoracic echocardiography, 9 (8.0%) had grade 2 mitral regurgitation, and 6 (5.4%) of these had reoperations (5 replacements and 1 repair). There were no deaths, strokes, or device-related complications. CONCLUSIONS: Multiple surgical teams performed robotic mitral valve repairs safely early in development of this procedure, with a reoperation rate of 5.4%. Advancements in robotic design and adjunctive technologies may help in the evolution of this minimally invasive technique by decreasing operative times.

Robot-assisted surgery: training and re-training surgeons.

A renaissance in cardiac surgery is occurring. Cardiac operations are being performed through smaller incisions with enhanced technological assistance. Specifically, minimally invasive mitral valve surgery has become standard for many surgeons. At our institution, we have developed a robotic mitral surgery program with the da Vinci telemanipulation system, which has recently gained FDA-approval. Initial results are reported. Despite procedural success, implementation of new technology requires restructuring training programs and re-training senior surgeons. Ultimately, our desire for improved and less traumatic patient care will continue to drive this new technology into the future.

A carotid stenosis model in canines.

A carotid stenosis model was developed in canines in order to study the effects of systemic blood pressure and hemodilution on cerebrovascular perfusion and metabolism during cardiopulmonary bypass in the setting of significant coexistent inflow stenosis. Under general anesthesia, through a low midline neck incision, the carotid sheath was entered and the carotid artery was isolated and retracted medially. The vertebral artery could be identified posterolaterally. After ligating the vertebral artery with a 00 silk tie, carotid stenosis was created by tying bilateral carotid arteries over an 18-gauge needle using a 00 silk tie. The needle was then removed, leaving a tight stenosis. To determine the degree of stenosis, arteriograms were performed, revealing high-grade lesions of greater than 90% stenosis in the carotid arteries and absence of flow through the vertebral arteries. Cerebral blood flow studies during cardiopulmonary bypass (CPB) were performed, revealing a significant decline. Carotid arteries were harvested at the conclusion of the experiments, revealing tight lesions on direct inspection. The mean gradient measured across stenotic segments was >25 mm Hg. In conclusion, a carotid stenosis model can be created successfully in dogs by ligating the vertebral arteries bilaterally and simply using the shaft of a needle to standardize the lumen size of the carotid arteries. We found the diameter of an 18-gauge needle sufficient to produce stenoses of greater than 90% as evidenced by arteriograms.

Evolution of mitral valve surgery: toward a totally endoscopic approach.

BACKGROUND: Our study evaluates a series of video-assisted minimally invasive mitral operations, showing safe progression toward totally endoscopic techniques. METHODS: Consecutive patients with isolated mitral valve disease underwent either manually directed (n = 55) or voice-activated robotically directed (n = 72) video-assisted mitral operations. Cold blood cardioplegia, a transthoracic aortic clamp, a 5-mm endoscope, and a 5-cm minithoracotomy were used. This video-assisted minimally invasive mitral operation cohort was compared with a previous sternotomy-based mitral operation cohort (n = 100). RESULTS: Group demographics, New York Heart Association classification, and cardiac function were similar. Repairs were performed in 61.8% manually directed (n = 34), 75.0% robotically directed (n = 54), and 54% sternotomy-based (N = 54) mitral operations. The robotically directed technique showed a significant decrease in blood loss, ventilator time, and hospitalization compared with the sternotomy-based technique. Manually directed mitral operations compared with robotically directed mitral operations had decreased arrest times (128.0 +/- 4.5 minutes compared with 90.0 +/- 4.6 minutes; p < 0.001) and decreased perfusion times (173.0 +/- 5.7 minutes compared with 144.0 +/- 4.6 minutes; p < 0.001). In the minimally invasive mitral operation cohort, complications included reexploration for bleeding (2.4%; n = 3) and one stroke (0.8%), whereas the 30-day mortality was 2.3% (n = 3). CONCLUSIONS: Video-assisted mitral surgery provides safe and effective results when compared with conventional sternal approaches. These positive results show a safe and stepwise evolution toward a totally endoscopic mitral valve operation.

Robotic surgical training in an academic institution.

OBJECTIVE: To detail robotic procedure development and clinical applications for mitral valve, biliary, and gastric reflux operations, and to implement a multispecialty robotic surgery training curriculum for both surgeons and surgical teams. SUMMARY BACKGROUND DATA: Remote, accurate telemanipulation of intracavitary instruments by general and cardiac surgeons is now possible. Complex technologic advancements in surgical robotics require well-designed training programs. Moreover, efficient robotic surgical procedures must be developed methodically and safely implemented clinically. METHODS: Advanced training on robotic systems provides surgeon confidence when operating in tiny intracavitary spaces. Three-dimensional vision and articulated instrument control are essential. The authors' two da Vinci robotic systems have been dedicated to procedure development, clinical surgery, and training of surgical specialists. Their center has been the first United States site to train surgeons formally in clinical robotics. RESULTS: Established surgeons and residents have been trained using a defined robotic surgical educational curriculum. Also, 30 multispecialty teams have been trained in robotic mechanics and electronics. Initially, robotic procedures were developed experimentally and are described. In the past year the authors have performed 52 robotic-assisted clinical operations: 18 mitral valve repairs, 20 cholecystectomies, and 14 Nissen fundoplications. These respective operations required 108, 28, and 73 minutes of robotic telemanipulation to complete. Procedure times for the last half of the abdominal operations decreased significantly, as did the knot-tying time in mitral operations. There have been no deaths and few complications. One mitral patient had postoperative bleeding. CONCLUSION: Robotic surgery can be performed safely with excellent results. The authors have developed an effective curriculum for training teams in robotic surgery. After training, surgeons have applied these methods effectively and safely.

Robotic Nissen fundoplication: alternative surgical technique for the treatment of gastroesophageal reflux disease.

The first robotic Nissen fundoplication using the da Vinci robotic surgical system was performed on a 56-year-old woman with a 20-year history of severe gastroesophageal reflux disease refractory to medical management. The recovery was uneventful, and follow-up continues.

Robotic cardiac valve surgery: transcending the technologic crevasse!

"The man with a new idea is a crank until the idea succeeds."--Mark Twain. With the profound public stress for minimally invasive surgery that guided General Surgery, Cardiothoracic Surgery has progressed with warranted enthusiasm. The explosion of technological advancements in optics, instrumentation and cardiopulmonary bypass has permitted minimally invasive cardiac procedures to be performed with safety, efficiency, and efficacy. In this chapter, we review the evolution of minimally invasive cardiac valve surgery. The articles of leading minimally invasive valve surgeons, both European and American, are reviewed. The indications for minimally invasive surgery are explained. Furthermore, the present day state of "robotic" mitral valve surgery is described.

The evolution and early experience with robot-assisted mitral valve surgery.

Cardiac surgeons, with a warranted enthusiasm, have embraced minimally invasive surgery. The acceleration of technological advances in optics, instrumentation, and cardiopulmonary bypass has allowed safe, effective, and efficient minimally invasive cardiac procedures. In this Technology Focus section, we review the evolution and early experience with robot-assisted mitral valve surgery. The articles of leading minimally invasive cardiac surgeons, both American and European, are reviewed to define the development toward cardiac robotic surgery. The current state of robotic mitral surgery is described.

Anterior thoracotomy wound complications in minimally invasive direct coronary artery bypass.

BACKGROUND: The minimally invasive anterior thoracotomy for beating heart coronary bypass offers a modest 10-cm incision and avoids the morbidity of extracorporeal circulation. This study examines minimally invasive direct coronary artery bypass (MIDCAB) wound complications and contributing comorbid factors. METHODS: A retrospective, single-institution review of 165 consecutive MIDCAB cases performed between March 1996 and August 1999 examined all wound abnormalities. Two surgeons performed all cases. RESULTS: Wound complications occurred in 15 patients (9.1%), including three (1.8%) incisional hernias, four (2.4%) superficial dehiscences, three (1.8%) wound infections, three (1.8%) chronic pain syndromes, and two (1.2%) seromas. Two patients with incisional hernias required operative repair. The remaining wound abnormalities responded to conservative therapy. Two chronic pain syndrome cases resolved spontaneously, but the third required advanced pain management. In contrast to MIDCAB, the sternotomy wound complications proved significantly less prevalent (n = 5259, 1.1% vs 9.1%, p < 0.005). CONCLUSIONS: Although MIDCAB offers several advantages over standard approaches, these data suggest that anterior thoracotomy wound complications are not insignificant and may be underestimated by those exploring minimally invasive options.

Differences in myocardial and peripheral VEGF and KDR levels after acute ischemia.

BACKGROUND: Recent clinical use of vascular endothelial growth factor (VEGF) in the treatment of both myocardial and peripheral ischemia has suggested the possibility of tissue specific coregulation of VEGF and its receptors (eg, kinase domain region [KDR]). The present study was performed to detect the relationship between VEGF and KDR protein levels after acute myocardial and peripheral ischemia. METHODS: Eleven dogs were divided into two groups: peripheral ischemia (n = 6, ligation of major limb arteries) and myocardial ischemia (n = 5, circumflex artery ligation). Muscle biopsy specimens were taken from the perfusion territories of the occluded circumflex artery and limb arteries 3 hours and 6 hours after ligation. Protein levels were determined using Western blot analysis. RESULTS: In myocardium, VEGF levels increased on average eightfold from baseline (p < 0.05) both 3 hours and 6 hours after occlusion, whereas myocardial KDR levels dropped by about 60% at 3 hours and 80% at 6 hours (p < 0.05). With limb ischemia, both VEGF and KDR levels were significantly elevated at 3 hours. CONCLUSIONS: In acute ischemia, regulation of VEGF and KDR may be controlled differently in cardiac and skeletal muscle. Myocardial KDR levels showed a significant decrease from baseline compared with a significant rise with peripheral ischemia.

Myocardial revascularization in the elderly using beating heart coronary artery bypass surgery.

BACKGROUND: Beating heart or "off-pump" coronary artery bypass (OP-CAB) has become an accepted method of myocardial revascularization by reducing the perioperative morbidity related to cardiopulmonary bypass (CPB). However, the efficacy of OP-CAB has not been well established in the elderly patient population. METHODS: OP-CABs were performed in 53 patients aged 75 years and older, at Pitt County Memorial Hospital from January 1996 to October 1999, either through a median sternotomy or an anterior thoracotomy. These results were compared with 220 patients who underwent standard coronary artery bypass graft (CABG) operation using CPB during the same time period. RESULTS: Mean patient age for both groups was 79+/-0.5 years and preoperative risk factors were similar. There were no differences in postoperative myocardial infarction, atrial fibrillation, bleeding, neurologic complications, or renal failure. There were no deaths after OP-CAB, compared with the 7.6% operative mortality rate after CABG (p<0.05). The OP-CAB group had a significantly shorter postoperative length of stay (4.4+/-0.4 days vs. 8.4+/-0.6 days) and lower transfusion requirements (0.4+/-0.1 units packed red blood cells vs 1.9+/-0.2 units packed red blood cells) than the CABG group. CONCLUSIONS: Our data demonstrate that OP-CAB is a safe and efficacious method of myocardial revascularization in the elderly, and may actually be preferential in these patients when applicable.

Minimally invasive videoscopic mitral valve surgery: the current role of surgical robotics.

OBJECTIVE: Recently, the efficacy of video-assisted mitral valve surgery has been demonstrated. The evolution of this technology has been relatively rapid. In this article we review this development and predict the future of endoscopic and robotic-enabling technology for cardiac valve operations. METHODS: A new video-assisted mitral valve operation is described and results discussed. The majority of each valve operation was done through assisted vision and near endoscopically. Cardiopulmonary bypass was established via femoral cannulation, and blood cardioplegic arrest induced using a new percutaneous, transthoracic cross-clamp. A 5 to 6-cm minithoracotomy was used in each patient. Videoscopy was helpful for suture placement, chord reconstruction, leaflet resection, knot tying, and valve ring or prosthesis positioning. A voice-activated robotic arm was used to direct the camera in many instances. RESULTS: Thus far a total of 110 patients have undergone this operation successfully with a 0.9% operative mortality. Our early series (N = 31), published with cost data, is reviewed in detail. Cardiopulmonary perfusion and cross-clamp times for all 100 patients were longer than for conventional sternotomy patients at 158 +/- 3.9 and 110 +/- 3.6 minutes, respectively, versus 121 +/- 4.6 and 90 +/- 4.6 (N = 105); however, there have been less complications. Operative, perfusion, and arrest times have fallen progressively to 144 +/- 4.5 and 90 +/- 4.5, respectively (N = 55 Aesop 3000 cases). Complex repairs and replacements have become routine with anterior leaflet pathology addressed. Bleeding, ventilatory times, blood transfusions, and hospital stay have been reduced. One patient required reoperation for a technically failed repair and two renal patients had late endocarditis. We have used voice-activated, robotic (Aesop 3000) assistance for camera control in 51 of these patients. This addition has decreased camera motion artifact and lens cleaning, while providing direct "cerebral-eye" tracking of instruments for the surgeon. We were the first in the United States to apply the DaVinci articulated wrist robot to do a complete mitral repair and have done multiple repair with this articulated wrist device. CONCLUSIONS: From this and other work reviewed, we conclude that video-assisted and computer-assisted robotic techniques are safe and may be the pathway to truly endoscopic mitral valve operations. We are encouraged regarding the use of this new technology for mitral valve operations.