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Biportal fissureless video-assisted thoracoscopic surgery lobectomy

Alessandro Brunelli

HISTORY

The first reports, from Italy and North America, regarding video-assisted thoracoscopic surgery (VATS) lobectomy performed according to modern technical and oncologic principles were published simultaneously. ¹ , ²

It took several years and significant technological improvements (dedicated VATS instruments and high definition [HD] video systems, among others) to facilitate the diffusion of this technique. Yet, a recent report from the Society of Thoracic Surgeons (STS) database showed that only about 30% of all lobectomies were performed by VATS, and in Europe this proportion was less than 10%. ³ Despite favorable outcomes and comparable oncologic results, there are still barriers that slow down adoption of this approach.

The Cancer and Leukemia Group B (CALGB) 39802 trial of the American Society of Clinical Oncology has defined VATS lobectomy by the presence of the following criteria: no rib spreading, one 4-8 cm utility incision, one to three additional ports, video guidance, individual dissection and transection of the hilar structures, and standard node sampling or dissection. ⁴ These criteria have set standards allowing for comparative analyses and pooling of data from different centers.

Several papers have now confirmed the validity of VATS lobectomy as a safe, economically and oncologically sound technique. However, the surgeon must use their wisdom and employ an evidence-based approach to recognize its limitations and applicability in all lung resections and all thoracic patients.

PRINCIPLES AND JUSTIFICATION

VATS anatomic lung resections are governed by the same principles as those for open surgery. When VATS lung resections are performed for malignant disease, preoperative surgical staging of the mediastinum with positron emission tomography and endobronchial ultrasound or mediastinoscopy are of paramount importance. What matters is not the ability to perform a VATS procedure but the ability to offer the correct treatment with it. The computed tomography scan remains a useful tool to map the hilar structures, define their anatomic relationship, and provide additional information regarding any potential intraoperative challenges. The slightest hint of being out of one’s depth should encourage the wise surgeon to revert to the procedure with which they are most comfortable. Therefore, in the modern era of VATS, a quality measure should be the number of planned conversions versus unplanned ones.

A recent consensus statement from 50 VATS lobectomy experts states that VATS lobectomy is indicated for tumors of a size less than 7 cm and for N0/N1 disease. VATS lobectomy is contraindicated when there is the suspicion of chest wall involvement and relatively contraindicated if tumor invades hilar structures. ⁵

Clearly, the inability to ventilate one lung and to provide a complete resection remains the main contraindications for VATS resections.

In experienced centers, previous chest surgery, the presence of bulky lymph nodes, endobronchial pathology, pericardial or diaphragmatic invasion, or neoadjuvant chemo radiotherapy are no longer absolute contraindications.

The importance of remaining safe and oncologically sound cannot be emphasized enough against the urge to record a successful VATS resection.

In a recent large multicenter study analyzing the occurrence of intraoperative major complications during VATS lobectomy, the conversion rate was 5.5% (49% for complications, 29.0% for technical reasons, and 22.0% for oncologic causes). Twenty-three percent of the in-hospital mortalities were related to the major intraoperative complications. ⁶ Vascular injuries were reported in 2.9% and led to conversion in nearly 80.0% of cases. The probability for conversion for non-oncological reasons decreased with experience (2.4% every ten cases). This information may represent a reference to assess quality of surgical care and can be used during preoperative counseling.

PREOPERATIVE ASSESSMENT AND PREPARATION

Preoperative evaluation for VATS anatomic lung resection follows the same principles as for the open approach. The American College of Chest Physicians functional algorithm is used. ⁷

A preliminary cardiologic evaluation is performed in all patients.

Those patients with low cardiologic risk or with optimized cardiologic performance may proceed with the rest of functional workup. Forced expiratory volume in 1 second (FEV1) and diffusion capacity of the lung for carbon dioxide (D_LCO) are systematically measured in all patients. Patients deemed at low cardiologic risk and with both predicted postoperative forced expiratory volume in 1 second (ppoFEV1) and predicted postoperative diffusion capacity of the lung for carbon dioxide (ppoD_LCO) greater than 60% are regarded at low risk for surgery (risk of mortality lower than 1%). Patients with either ppoFEV1 or ppoD_LCO between 30% and 60% should undergo a low technology exercise test as a screening test. If the performance on the low technology exercise test is satisfactory, patients are regarded at moderate risk (morbidity and mortality rates may vary according to the values of split lung functions, exercise tolerance, and extent of resection). A cardiopulmonary exercise test is indicated when ppoFEV1 or ppoD_LCO are lower than 30% or when the performance at the stair climbing test or shuttle walk test is not satisfactory (i.e., altitude reached at stair climbing test <22 m or a shuttle walk distance <400 m). A maximal oxygen consumption (VO₂ max) of less than 10 mL/kg/min or 35% predicted indicates high risk for mortality when undergoing a major anatomic resection.

However, current functional algorithms are based on data that included patients operated on through an open approach. Several reports have now shown a reduction in morbidity rates in patients operated on through VATS. ⁸ – ¹¹ This is probably explained by the minimal impact of this operation on the chest wall mechanics. This effect is even more evident in patients with compromised pulmonary function. For instance, in patients with an FEV1 of less than 60% or a D_LCO of less than 60%, FEV1 and D_LCO remained associated with complications only in patients undergoing thoracotomy but not thoracoscopy. ¹²

Similarly, in patients submitted to lobectomy and with FEV1 of less than 60% registered in the STS database, those operated on through thoracotomy had an increased pulmonary complication rate compared with VATS patients. No significant difference was noted in patients with an FEV1 of more than 60% predicted. ¹³

These findings are confirmed by a recent investigation showing lower respiratory complications and shorter hospital stay after VATS lobectomy compared with thoracotomy in chronic obstructive pulmonary disease patients. ¹⁴

A recent analysis from the STS database ¹⁵ showed that patients with a ppoFEV1 of less than 40% had significantly lower morbidity and mortality rates after VATS lobectomy than their case-matched counterparts operated on through thoracotomy (21.9% vs. 12.8% and 0.7% vs. 4.8%, respectively). Similarly, patients with a ppoD_LCO of less than 40% had also reduced morbidity and mortality rates after VATS compared to thoracotomy. (10.4% vs. 14.9% and 2% vs. 5.2%, respectively).

In addition to these important findings, other studies have shown better preservation of pulmonary function compared to preoperative values in patients undergoing VATS lobectomy compared to thoracotomy. ¹⁶ , ¹⁷

A recent study from the European Society of Thoracic Surgeons database has showed that low aerobic capacity (VO₂ max) before surgery is not associated with increased risk of cardiopulmonary complications or mortality after VATS lobectomy, confirming the beneficial effect of this approach in high risk patients and questioning the traditional operability criteria in this subset of patients. ¹⁸

It appears likely that, with the increasing number of patients operated on through VATS, we will be able to verify whether traditional pulmonary thresholds of operability (mostly derived from series of patients operated on through thoracotomy) should be updated.

ANESTHESIA

The anesthetic technique used for VATS lobectomy does not differ from that used for any major thoracic surgical procedure. Induction is performed intravenously and endobronchial intubation takes place following administration of a nondepolarizing neuromuscular blocking drug. Maintenance is with an inhalational agent such as isoflurane.

The patient is then positioned in the lateral decubitus position. It is important to flex the table at the level of the inferior scapular angle to provide maximum spread of intercostal spaces for access. This position facilitates dropping the pelvis away from midline to prevent hindrance of free movement of the camera and other surgical instruments introduced from the inferior port.

One-lung ventilation is necessary to provide an adequate and quiet operating field. There is controversy regarding the use of left-sided tubes. Most believe they should always be used to prevent collapse of the right upper lobe, as it almost always originates close to the carina. Contralateral lung intubation is necessary, however, if major maneuvers are anticipated on the bronchial tree. The successful endobronchial tube position is confirmed with a flexible bronchoscope before the patient is turned to the lateral position.

The choice of double lumen tube or bronchial blocker rests with the team and institutional preference. A double lumen tube is generally preferred because it provides selective ventilation of the contralateral lung, while allowing more rapid collapse of the ipsilateral lung.

Following completion of the resection the residual lung parenchyma should not be reinflated or tested for air leaks before adequate and thorough suctioning of the bronchial tree has taken place. Providing no further actions are required, the chest is closed and spontaneous ventilation is reestablished in the usual manner. Extubation should be accomplished in the operating room and postoperative care is monitored in a high dependency unit.

OPERATION

General principles

A standard set-up is with one monitor placed on each side of the table in front of the surgeon and the scrub nurse.

I perform VATS lobectomies using a 10 mm, 30-degreeangled HD video thoracoscope. The 30-degree scope allows a superior view within the chest cavity.

The surgeon and the assistant are positioned on the anterior (abdominal) side of the patient. The surgeon can change position and place themselves cranially or caudally with respect to the assistant depending on the different steps of the operation.

The scrub nurse is opposite the assistant and follows the operation on a separate screen while still positioned face to face with the operating surgeon.

Initially, a 3.5-4.0 cm anterior utility incision is made without any soft tissue retractor or rib spreading. The wound is protected by a plastic soft tissue retractor kept in place by a ring in the chest cavity and one outside the skin (Alexis retractor, Applied Medical Resources Corporation, Rancho Santa Margarita, California, United States). This incision is usually placed at the 4th-5th intercostal space, between the tip of the scapula and the breast in the anterior axillary line.

Initial inspection is of paramount importance in order to identify any unexpected pathology and adhesions, as well as to assess the level of the diaphragm. A second 2.0-2.5 cm port is positioned more posteriorly at the level of the 7th intercostal space, just anterior to a straight line down from the tip of the scapula.

Typical placement of right and left biportal incisions is shown in Figure 15.1.

The camera is usually placed in the utility incision for the upper lobes, whereas it is usually placed in the inferior port for the middle and lower lobes. The camera position can be changed from one port to another if necessary, particularly during specific steps of the operation (parenchymal division, lymphadenectomy, etc.).

Most of the hilar dissection can be performed bluntly, either with a dissecting instrument (peanut) or a thoracoscopic suction device, which also keeps the field dry during dissection. The dissection can be complemented with monopolar diathermy with a long shielded tip. We recommend use of endoscopic forceps with axial handles to assist during this step. An elastic vascular loop is advised for gentle retraction of vessels when the endo-stapler is negotiated around them.

Lobar hilar elements and fissures are divided sequentially, with appropriate endoscopic staplers. For each anatomic lobectomy, the specific pulmonary vein is usually the first structure to be transected.

We use the so-called fissureless or fissure-last approach, in which the fissure is developed at the completion of the procedure after all the hilar elements have been transected. This approach minimizes visceral pleura and parenchymal injury, thus preventing alveolar air leaks. High energy devices can also be used to transect smaller pulmonary artery branches up to the size of 3-4 mm and for lymphadenectomy. At the conclusion of the operation, a single, apical 24 Fr chest tube is placed, generally through the inferior port in a midline position.

Right upper lobectomy

The camera is generally introduced through the utility incision, which facilitates the anterior view of the hilar structures. The lung is reflected posteriorly with endoscopic grasping clamps, usually introduced through the inferior port, and the pulmonary veins are identified. Blunt dissection is performed to identify the superior pulmonary vein and the bifurcation of the upper and middle lobe veins. Once the upper lobe veins have been clearly defined, they are dissected free with the use of a thoracoscopic DeBakey clamp, introduced through the inferior port. Division is accomplished with an endovascular stapler introduced through the inferior port, with the anvil positioned behind the superior pulmonary vein, which is then divided (see Figure 15.2). This procedure reveals the underlying pulmonary artery. In a similar manner, the pulmonary arteries to the upper lobe are mobilized and divided, beginning with the truncus anterior. The truncus anterior is first dissected using the DeBakey clamp and subsequently divided using an endoscopic vascular stapler, both introduced through the utility incision (see Figure 15.3 a-b). The posterior ascending segmental artery may be isolated and divided at this time or after division of the bronchus by using endoscopic vascular clips (Hem-olok system), a high energy device or a vascular stapler. The lung is retracted medially and dissection along the posterior pleura is performed at the level of the bronchial bifurcation, which facilitates bronchial dissection later from the anterior approach. Subcarinal lymphadenectomy can be performed at this stage. Changing the position of the camera from the utility incision to the inferior port may facilitate this step by allowing a better view of the posterior mediastinal pleura.

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