1� 2005 European Association for Cardio-thoracic Surgery

doi:10.1510/mmcts.2004.000422

Robotic video-assisted thoracoscopic thymectomy�

Federico Rea*, Giuseppe Marulli, Luigi Bortolotti

Division of Thoracic Surgery, University of Padua, via Giustiniani 2, 35128 Padua, Italy

Presentation of a minimally invasive surgical technique for thymectomy in patients affectedby myasthenia gravis (MG): robotic video-assisted thoracic surgery (VATS) is a surgical tech-nique applied to perform thymectomy and remove the entire mediastinal fat through a lefttranspleural approach.

Keywords: Thymectomy, myasthenia gravis, robotic surgery

Introduction and history

Myasthenia gravis (MG) is an autoimmune diseasethat affects neuromuscular transmission and deter-mines chronic weakness and fatigue at various levelsof striated muscles.

Since 1941, when Blalock w1x first reported results oftranssternal thymectomy in patients affected by MG,thymectomy has played a significant role constitutinga widely accepted therapeutic option in the integratedmanagement of MG.

Multiple techniques are described to remove the thy-mus in MG: transcervical thymectomy (basic or exten-ded) w2x, video assisted thoracoscopic thymectomy(VATS) w3–5x (classic or extended), transsternal thy-mectomy w6x (standard, extended or maximal), infra-sternal mediastinoscopic thymectomy w7x.

Basic techniques for thymectomy enable a radicalresection of the thymic gland through a single surgicalapproach; extended techniques associate more thanone access (i.e. transcervical plus transsternal incisionfor maximal thymectomy proposed by Jaretzki w8x):the rationale of extended techniques is to obtain acomplete resection of the visible thymus, the sus-pected thymus and cervical-mediastinal fat tissue (in

� Authors declare to have no conflict of interest and to beresponsible for any falsehoods or omissions.

* Corresponding author: Tel.: q39-049 821 2237, fax: q39-049 8212249.E-mail: federico.rea@unipd.it

which microscopic foci of thymic tissue may be con-tained) using a wide exposure.

In the last decade growing interest in minimally inva-sive surgical techniques has developed and recentlyrobotic surgery has affirmed itself as an evolution ofVATS.

The first surgical application of robotic technique wasdescribed by Loulmet and Reichenspurner in 1999:they performed a coronary by-pass w9–10x.

Subsequently robotic instruments were applied in oth-er fields too and, in 2001, Yoshino w11x described thefirst robotic thymectomy in the treatment of smallthymoma.

In 2003, Ashton w12x and Rea w13x published a casereport on robotic thymectomy in MG using two differ-ent approaches: the former surgeon from ColumbiaUniversity adopted a right-sided approach with com-pletion of the operation through a left-sided approach,the latter from the University in Padua used a left-sided approach only.

Surgical technique

After neurological assessment, preoperative evalua-tion includes: a radiogram and computed tomographyof the chest (Photo 1) to verify feasibility of the sur-gical procedure. Surgery is performed in the followingmanner: the patient is under general anaesthesia andhas a double-lumen endotracheal tube for selectivesingle lung ventilation during the time of operation. In

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Photo 1. The CT-scan shows hyperplasia of the thymus andexcludes any neoplastic pathologies.

Schematic 1. Schematic planning in the surgical room: the patientis positioned on the surgical table, the ‘Da Vinci’ robotic systemwith the surgical cart and the surgeons console are displaced.

Photo 2. The thoracic ports are placed after the identification of the5th and 3rd intercostal space and the arms of the ‘Da Vinci’ surgicalsystem are attached to the ports and are operative.

Video 1. The surgeon sits at the console containing a display show-ing the images obtained with the endoscopic camera and anymanipulators the surgeon uses to control the movements of surgicalendoscopic instruments. This system is equipped with an intuitive3-dimensional vision, a scale motion with tremor filtering and theEndoWrists with articulated movements permitting a full sevendegree of freedom.

Video 2. The mediastinal surface of the left pleural space isexplored and the anatomic structures are identified: the pericardi-um, the phrenic nerve and the mammary vessels.

Video 3. The operation starts with the removal of all the pericardio-phrenic angle fat tissue.

the surgical room (Schematic 1) the patient is posi-tioned left side up, 30 degrees on a bean bag. Thearms of the ‘Da Vinci’ surgical system (MMCTSLink17) are placed as follows: a camera port for the 3-dimensional 0 degree stereo endoscope is introducedthrough a 15 mm incision in the 5th intercostal spacein the anterior portion of the midaxillary region; two

additional thoracic ports are inserted through twoadditional 5 mm incisions in the 5th intercostal spaceon the midclavicular line and in the 3rd intercostalspace on the anterior portion of the midaxillary region(Photo 2).

The left arm has an EndoWrist instrument that graspsthe thymus; the right arm is an Endo-Dissector devicewith electric cautery function used to perform the dis-section (Video 1).

During surgery the hemithorax is inflated through thecamera port with CO2 ranging in pressure from 6 to10 mmHg. CO2 inflation is very useful to obtain a clearview within the chest and to allow an easier dissectionas it extends the mediastinal space.

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Video 4. Following the removal of the pericardio-phrenic angle fattissue, an incision is made from the bottom to the top of the retro-sternal part of the mediastinal pleura.

Video 5. The thymic tissue is dissected from the retrosternal space.

Video 6. Isolation of the thymus from the pericardial surface is alsoperformed from the bottom to the top.

Video 7. At the apical level the pleural incision is made to reach thearea that comprises the mammary vessels and the phrenic nerve.

Video 8. Mobilization and dissection of the thymus gland is per-formed from the aorto-pulmonary surface.

Video 9. The thymic gland is divided from the right mediastinal pleu-ra and the right inferior horn is dissected.

Video 10. The cervical fat is dissected from the retrosternal andjugular region to identify the upper horns of the thymus.

After careful exploration of the mediastinal pleuralspace (Video 2), the dissection of the fat tissue startsinferiorly at the left pericardiophrenic angle (Video 3).

The thymic gland is then divided from the retrosternalarea (Videos 4, 5) and the left inferior horn of the thy-mus is subsequently isolated and dissected from thepericardium (Video 6).

At the top of the mediastinum, the pleura is incisedin the area delimited by the mammary vessels in theanterior limit and by the phrenic nerve in the posteriorlimit (Video 7). At this point the lower part of the thy-mus is mobilized upwards and thymic tissue is dis-sected from the plane of the aorto-pulmonary window(Video 8). The dissection continues in the right sidewith the visualization of the right mediastinal pleuraand the right inferior horn (Video 9).

The isolation proceeds up to into the neck until thesuperior horns are identified and divided from the infe-rior portion of the thyroid gland (Videos 10, 11, 12).

The innominate vein is identified and the dissectioncontinues along the border of the innominate vein upto the point where the thymic veins are identified,clipped and divided (Video 13).

The dissection finishes in the lower right side (Video14).

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Video 11. The cervical left horn of the thymus is identified in theneck region. In this particular step it is important to carefully locatethe innominate vein.

Video 12. When the innominate vein is isolated, the cervical hornswith an apical traction are dissected.

Video 13. The thymic veins are visualized, doubly clipped and cut.

Video 14. Dissection of the thymic tissue from the right mediastinalpleura is completed to remove the fatty tissue of the right pericar-dio-phrenic angle.

Video 15. The entire specimen is finally mobilized and an Endo-Bagis introduced in the pleural space through the inferior port. The thy-mus is placed in the Endo-Bag and taken out. A chest tube isplaced and the lung is inflated under optical view.

Photo 3. Surgical specimen: the thymic gland and mediastinal fatare removed en-bloc.

The thymus gland, the anterior mediastinal and theneck’s fatty tissue are radically resected and thespecimen is placed in an Endo-Bag so it can beremoved by trocar incision. After the haemostasis, a28F drainage tube is inserted through the wound ofthe 5th intercostal space, the lung is reinflated and theother wounds are closed (Video 15, Photo 3).

The patient is extubated in the operating room and,subsequent to an adequate period of observation,returns to the floor of surgical thoracic ward.

The chest drainage tube is removed 24 h after surgeryand, if neurological evaluation is satisfactory, thepatient is discharged 48–72 h after surgery.

Results

● Thymectomy in MG is an effective therapy that pro-duces good clinical results.

● In literature the remission rate is comparable for thevarious surgical techniques proposed (Table 1).

● The transsternal approach is a widespread surgicaltechnique for thymectomy. The main advantages

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Table 1. Comparison of clinical results after thymectomy using different approaches.

Author No Approach Follow- Remission Improvementpatients up (years) rate (%) (%)

Masaoka w6x, 1996 375 Transsternal 7.9 47 42Papatestas w15x, 1987 962 Transcervical– 10.0 32 –

TranssternalCalhoun w2x, 1999 100 Transcervical 5.0 35 50Mineo w3x, 2000 31 VATS 3.3 36 60Mack w4x, 1996 33 VATS 1.9 18 70Mantegazza w5x, 1998 104 VAT extended 3.7 26.7 43Personal experience 24 Robotic VATS 1.5 12.5 66.7

Photo 4. The cosmetic results can be seen from the frontal viewand the lateral view.

are: an optimal exposition and dissection of the thy-mus and perithymic fat tissue and lower risks ofvascular and nervous injuries. Some disadvantagesinclude invasiveness of the approach and a longerhospitalization.

● The transcervical thymectomy, popularized by Coo-per et al. w14x, is a minimally invasive technique thatis easily accepted by young patients and neurolo-gists. The advantages are a short hospitalization,fewer complications and lower costs. The main crit-icism to this approach is related to the small spaceof access causing a crowding of instruments thusmaking surgical manoeuvres difficult and impossi-ble to perform a thymectomy that extends to theperithymic fat tissue.

● VATS thymectomy through the left- or right-sidedapproach is a minimally invasive technique that per-mits a good visualization of the anterior mediasti-num, achieving an extended thymectomy. Thedisadvantages are the 2-dimensional view of theoperative field and the limited manoeuvrability ofthe endoscopic instruments.

● The robotic approach combines the advantages ofminimally invasive techniques (fewer complications,minimal thoracic trauma, decreased postoperativepain, early improved pulmonary function, shorterrecovery period and optimal cosmetic results wPho-to 4x) and the specific advantages as an intuitive 3-dimensional vision, a scale motion with tremorfiltering and the endo-wrists with articulated move-

ments permitting a full seven degree of freedom.These characteristics allow an accurate dissection,easier than classic VATS, particularly in the neckwhere the dissection is more difficult. The disad-vantages of this approach include the initial highcosts of the robotic system, the early increasedoperative time and the learning curves associatedwith robotic technology.

● Between April 2002 and October 2003, 24 patientsunderwent thoracoscopic thymectomy with the ‘DaVinci’ surgical system at the Division of ThoracicSurgery of Padua. The operative time was 129 min(ranging from 60 to 240 min), no intraoperative mor-tality or complications were experienced; no con-version to median sternotomy and no moreaccesses were required. Post-operative complica-tions occurred in two cases (8.3%): one patient hada chylothorax, another patient had a haemothoraxcaused by bleeding from one access and both weretreated conservatively. Mean time of hospitaliza-tion after surgery was 2.7 days (ranging from 2 to14 days).

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