Ann Thorac Surg 2010;90:668-670. doi:10.1016/j.athoracsur.2010.02.029
© 2010 The Society of Thoracic Surgeons
Case Reports
Robotic-Assisted Resection of a Thymoma After Two Previous Sternotomies
Maheshwaran Sivarajah, MS,
Benny Weksler, MD*
Department of Surgery, Section of Thoracic Surgery, Thomas Jefferson University Hospital, Philadelphia, Pennsylvania
Accepted for publication February 15, 2010.
* Address correspondence to Dr Weksler, Section of Thoracic Surgery, Thomas Jefferson University Hospital, 1025 Walnut St, Ste 607, Philadelphia, PA 19107 (Email: benny.weksler{at}jefferson.edu).
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Abstract
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Robotic-assisted surgery has emerged as a new strategy for resection of thymomas. It may provide an option for patients who have had prior thoracic procedures, reducing the risks involved with another open procedure. We present a patient with a thymoma occurring after two prior sternotomies for cardiac procedures. A robotic-assisted thymectomy was performed successfully, with no complications. The minimally invasive approach of robotic-assisted resection of thymomas provides a safe alternative to redo sternotomy.
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Introduction
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Thymomas are rare intrathoracic neoplasms of the thymus with an annual incidence of approximately 0.15 per 100,000 person-years [1]. Surgical intervention remains the only curative treatment, traditionally performed through a median sternotomy, with complete resection of the tumor, thymus, thymic cervical extensions, and the surrounding perithymic fat. With the advent of improved optics and computer-assisted surgical systems, minimally invasive thymectomies by video-assisted or robotic techniques are becoming increasingly popular.
To date, to our knowledge, there are no reports of thymomas occurring after cardiac procedures, possibly because the thymus gland is removed to allow exposure of the pericardium and great vessels. The occurrence of a thymoma after a sternotomy for a cardiac procedure is potentially a difficult problem. A redo sternotomy carries well-established risks associated with injury, namely to the heart, great vessels, and patent venous or arterial grafts [2]. Some recommend groin cannulation before sternotomy to ensure arterial and venous access in case of a major complication during the redo sternotomy.
We present a patient diagnosed with an invasive thymoma after undergoing his first and second aortic valve replacements, 28 and 17 years previously, respectively. He was treated successfully with a robotic-assisted thymectomy without a redo sternotomy using the da Vinci Surgical System (Intuitive, Sunnyvale, CA).
A 74-year-old man was seen at our office with a 3-month diagnosis of myasthenia gravis and a history of an anterior mediastinal mass. He had a significant history of aortic valve endocarditis and aortic valve replacement with a porcine valve in 1981. In 1992 he underwent a second aortic valve replacement with a mechanical valve and coronary artery bypass grafting. In 2004 he had an incidental finding of a 3-cm anterior mediastinal mass, suspicious for a thymoma. The mass was monitored with serial chest computerized tomography (CT) imaging and slowly increased in size to 5 cm in its largest diameter in late 2008. The patient was not offered surgical intervention because of the risks involved with a third sternotomy.
In November 2008, he was diagnosed with myasthenia gravis after presenting with ptosis and an increased acetylcholine receptor antibody level of 96 nmol/L (normal range, 0 to 0.4 nmol/L). He was initially treated with pyridostigmine and prednisone but was admitted to our institution in June 2009 with worsening right-sided ptosis and head droop, along with bilateral facial weakness. A CT showed a mass, now measuring 6 cm in its largest diameter, in the anterior mediastinum (Figs 1 and 2).
After proper medical management of his worsening myasthenia, he underwent a robotic-assisted resection of the thymic remnant containing a 5.5-cm x 5-cm x 3-cm thymoma, pathologically staged as Masaoka stage IIb and World Health Organization type AB. Resection margins were histologically free of tumor. During the procedure, we found adhesion between the lung and the mediastinum that we were able to take down robotically.
More difficult was the dissection of the residual thymus from the aortic cannulation site and the innominate vein. Careful dissection was done by using monopolar electrocautery, guided by a superior optics and 3-dimensional visualization of the mediastinal structures. After complete resection of the mass and surrounding thymus, we placed the specimen in a Lap-Sac (Cook Medical, Bloomington, IN). To remove the large mass, we did a subperiosteal resection of a 3-cm segment of rib. The procedure took 126 minutes, with 111 minutes of robotic docked time.
The patient was discharged home on postoperative day 1 without any perioperative complications. He underwent adjuvant radiotherapy (50.5 Gy in 28 fractions). At the 6-month follow-up, the patient was asymptomatic, and his medications were reduced by 50%.
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Comment
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Robotic-assisted surgery provides the potential to perform complex surgical procedures within a small, often difficult to reach, anatomic area. Additionally, it has major affects on postoperative pain and function, hospital stay, and cosmesis. In a series of 14 patients with mediastinal masses who underwent minimally invasive operations with the da Vinci robotic system, 9 of whom underwent thymectomies, the median overall operative time was 166 minutes [3]. There were no intraoperative complications or surgical deaths. One patient required conversion to a standard thoracotomy.
In a subsequent series of 15 patients who underwent robotic-assisted thymectomy with the da Vinci robotic system, 7 of whom had thymomas and another 3 had myasthenia gravis and normal thymus, there were no conversions, intraoperative complications, nor deaths. The mean operative time was 96 minutes, with a mean robotic time of 48 minutes. The median hospital stay was 2 days with a median follow-up of 1 year. Patients who underwent an extended thymectomy through a median sternotomy had a mean operative time of 140 minutes with a mean hospital stay of 4 days [4]. In another series of robotic-assisted thymectomies in 21 patients with myasthenia gravis, the mean operative time was approximately 60 to 90 minutes, and 40% were discharged on the same day and an additional 40% within 24 hours [5].
Robotic-assisted procedures may become an invaluable tool in patients who have had previous sternotomies. Redo sternotomy is associated with an increased risk of cardiac injury and catastrophic hemorrhage, with elevated mortality and morbidity. A review of 612 redo sternotomies during an 11-year period performed largely for a coronary artery bypass grafting or valve replacement found that 56 patients had injuries at the time of the redo sternotomy, with the most commonly injured structure being a patent coronary artery bypass graft (46%), followed by the right ventricle (21.4%) and the great vessels (10%) [6].
In an additional review of 1847 patients undergoing reoperative cardiac procedures, 145 intraoperative adverse events were observed in 127 patients, including injuries to the bypass grafts in 47, heart in 38, great vessels in 28, and ischemia without graft injury in 22. A major risk factor for adverse events was previous cardiothoracic procedures (p = 0.012). Poor outcomes (stroke, myocardial infarction, death) were seen in 24 of the 127 patients (19%) [2].
Minimally invasive operations on chests undergoing reoperation is feasible but technically challenging. In a review of 40 patients who underwent video-assisted thoracic surgery and had prior thoracic procedures, conversion to an open procedure occurred in only 2 patients (5%) due to adhesions. The mean hospital stay was 5.1 ± 3.2 days, with no mortality or intraoperative complications [7].
The resection of anterior mediastinal masses in patients after a prior mediastinal operation may be feasible with modifications in patient positioning and port location [8]. We present a case in which the da Vinci surgical robotic system was successfully used in a patient with two prior sternotomies. Although the procedure was technically challenging, it was completed in about 2 hours and did not carry any complications. The patient was discharged home in 1 day.
Our series of 20 consecutive robotic mediastinal procedures (presented at the 23rd Annual Meeting of the General Thoracic Surgical Club), had an operative time of 126 ± 34 minutes and robotic time of 80 ± 28 minutes. Hospital stay was 1.7 days, and only one patient had a postoperative complication (atrial fibrillation).
In conclusion, robotic-assisted thoracic surgery is an effective alternative in patients with mediastinal masses and a history of sternotomies. Robotic exploration of a reoperated-on mediastinum may preclude the complications related to a redo sternotomy and appears to be safe if performed carefully in experienced hands. With the evolution of robotics and the advancements of instrumentation, we believe that patient morbidity, time to recovery, and long-term outcome will continue to improve.
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References
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- Engels EA, Pfeiffer RM. Malignant thymoma in the United States: demographic patterns in incidence and associations with subsequent malignancies Intl J Cancer 2003;105:546-551.[Medline]
- Roselli EE, Pettersson GB, Blackstone EH, et al. Adverse events during reoperative cardiac surgery: frequency, characterization and rescue J Thorac Cardiovasc Surg 2008;135:317-323.
- Bodner J, Wykypiel H, Greiner A, et al. Early experience with robot-assisted surgery for mediastinal masses Ann Thorac Surg 2004;78:259-266.[Abstract/Free Full Text]
- Savitt MA, Gao G, Furnary AP, Swanson J, Gately H, Handy JR. Application of robotic-assisted techniques to the surgical evaluation and treatment of the anterior mediastinum Ann Thorac Surg 2005;79:450-455.[Abstract/Free Full Text]
- Kernstine KH. Robotics in thoracic surgery Am J Surg 2004;188:89S-97S.[Medline]
- Ellman PI, Smith RL, Girotti ME, et al. Cardiac injury during resternotomy does not affect perioperative mortality J Am Coll Surg 2008;206:993-999.[Medline]
- Yim APC, Liu H-P, Hazelrigg SR, et al. Thoracoscopic operations on reoperated chests Ann Thorac Surg 1998;65:328-330.[Abstract/Free Full Text]
- Marshall MB. Thorascopic mediastinal resection after median sternotomy and mediastinotomy Ann Thorac Surg 2009;88:1371-1373.[Abstract/Free Full Text]
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Abstract
Introduction
