Pulmonary Sleeve Resection

Anatomy and Physiology

Understanding the branching of the bronchial tree and pulmonary vasculature is integral to understanding surgical techniques for lung resection. The right lung comprises three lobes, while the left lung has two lobes. The right-sided airway has a relatively short right mainstem bronchus with the first branch into the right upper lobe (RUL) followed by bronchus intermedius (BI). The bronchus intermedius then branches into the right middle lobe (RML) anteriorly and right lower lobe (RLL). The left side has a longer (approximately 4 to 5 cm) and more horizontally oriented left mainstem bronchus, which divides into a left upper lobe (LUL), and a left lower lobe (LLL) bronchus.[9] In terms of anatomic location, pulmonary sleeve resection (PSR) is most commonly performed at the RUL bronchus (approximately 75%) due to the advantage of a relatively longer BI for reconstruction.[2][9] The other less common sites are on the left - LUL (16%) and LLL (8%).[9]

A standard PSR is considered when a formal lobe is resected with a portion of the bronchus followed by re-anastomosis of the bronchi's cut-ends. Extended sleeve resection is considered with multiple lobes resected, for example, RUL and RML bi-lobectomy with bronchial reconstruction.[1] In contrast, a pneumonectomy completely removes one-side of the lung without reconstruction of the bronchus.[9] Segmentectomy and lobectomy combined can also be performed as an atypical type of PSR.[10] There are four types of extended SL categorized by anatomic location of excision and reconstruction.[1] PSR may also require an additional arterioplasty or venoplasty. A "double sleeve" terms have also been described to indicate combined vascular and bronchial resections.[7]

Indications

Usually, for locally advanced lung cancer, the tumor or lung lesion extends into a portion of the main bronchus. After resecting the bronchial portion, there must be sufficient disease-free bronchial tissue to be re-anastomosed to preserve lung parenchyma on the affected side. Pulmonary sleeve resection (PSR) can be performed for central tumors, benign or low-grade.[10]

Lung cancer staging has evolved over the past decade. The most current edition is the 8th edition with the American Joint Committee on Cancer (AJCC) and Union Internationale Contre le Cancer (UICC) published in 2017. The TNM classification (tumor[T], lymph node[N], and metastasis[M]) describes a specific classification of lung tumors based on location, lymph node involvement, and areas of metastasis.[11] Typically, early-stage I to IIb lung cancer and either N0 or N1 (hilar) nodal disease are considered eligible for PSR. With advancements in preoperative neoadjuvant treatment, a select group of patients with micrometastases to single-station N2 disease may benefit from PSR after successful downstaging with induction treatment.

Examples of pathologies requiring PSR include carcinoid tumors, non-small-cell lung cancer (NSCLC). Other pathologies may also be indicated as squamous cell carcinoma, myofibroblastic tumor, adenoma, metastatic sarcoma, or granular cell tumors.[7]

Contraindications

Generally, advanced stage lung cancers are not amenable to local surgical resection. Using the most recent AJCC 8th edition classification, this will include tumors with metastasis to mediastinal lymph nodes and T4 tumors invading mediastinal structures.[11] If M1 (distant metastases) or N3 disease (contralateral nodal metastases) exists, surgery is not recommended.[1]

Anatomic considerations are the most important when planning surgical intervention for pulmonary sleeve resection (PSR) versus pneumonectomy. Patients should only undergo PSR if this achieved complete excision of the tumor (R0). Residual tumor after resection will place patients to be at risk for locoregional recurrence.

If patients have unfavorable pre-operative testing such as cardiac disease or preoperative pulmonary function test demonstrated poor surgical candidacy, formal major operative lung resection should be discouraged.

Equipment

Equipment for the pulmonary sleeve resection (PSR) includes but is not limited to the following:

• Operating room
• Flexible bronchoscope
• Sterile drapes
• Sterile gowns
• Sterile supplies 
• Thoracic/rib retractor
• Surgical knives
• Surgical clamps
• Absorbable and non-absorbable sutures
• Surgical staplers
• Chest tubes/drains

Equipment for the pulmonary sleeve resection procedure should be available in a thoracic surgery operating room with appropriate instruments and staff.

Personnel

Personnel needed to perform pulmonary sleeve resection (PSR) includes but is not limited to the following:[12]

• Trained thoracic surgeon
• Anesthesiologist with thoracic surgical experience
• First surgical assistant
• Surgical technician
• Surgical nurse

Post-operative care should ideally be in a specialized intensive care unit where intensivists and nurses are familiar with post-operative thoracic patients' specialized care.

Preparation

Pre-operative workup is included to ensure patients are adequate surgical candidates. This includes a physical examination, pulmonary function testing, bronchoscopy, computed tomography (CT), and 18F-fluorodeoxyglucose PET scan.[1] 

A cardiac workup should be recommended if a patient has pre-operative risk factors, such as a long history of smoking. Invasive mediastinal staging such as endobronchial ultrasound (EBUS) or mediastinoscopy should be performed to evaluate for the nodal disease if clinically suspected.[10] 

Depending on the indication for lung tumor resection, patients may undergo neoadjuvant chemotherapy and possibly radiation before undergoing pulmonary sleeve resection (PSR).[7]

Technique or Treatment

Pulmonary sleeve resection (PSR) is considered more technically difficult than pneumonectomy because of the reconstruction required. The preferred incision is an open thoracotomy approach with the patient in a lateral decubitus position. All patients should be intubated, require general anesthesia, Foley catheter placement, and adequate intravenous access. Arterial line placement is also preferred to measure arterial blood gases during the procedure. Lung isolation can be performed with a single-lumen endotracheal tube and bronchial blocker or double-lumen endotracheal tube.

SL and PSR require a few principles:[13]

• Complete resection of the tumor with clear margins (for lung cancer)
• End-to-end re-anastomosis with absorbable braided or monofilament suture
• Covering anastomosis with some form of vascularized tissue

After resection of the affected lobe, bronchial margin tissue is sent for a frozen section to confirm a disease-free area before proceeding with bronchoplasty. After performing the bronchial anastomosis, it is also recommended to buttress the bronchoplasty with a vascularized flap. Various coverings can be harvested, including intercostal muscle flap, pericardial fat pad, or thymic fat wrap. Mediastinal lymphadenectomy should be performed. Usually, a chest tube will be left in place, and an intercostal nerve block is performed with a local anesthetic. Bronchoscopy is usually performed at the end of the procedure to evaluate the bronchial anastomosis and evacuate pulmonary secretions accumulated during the procedure.[7]

Recently, minimally invasive thoracic surgical techniques have advanced in all facets of lung resection surgery. Although technically more challenging, these advanced thoracic surgical techniques can be applied to PSR as experience grows. Minimally invasive techniques include VATS or robotic thoracic surgery.[7] Instead of a thoracotomy incision, VATS can be performed using several thoracoscopic ports.[14] Robotic SL can be performed using robotic ports and system and must be performed in centers experienced in robotic thoracic surgery.[15][16]

Complications

Mortality after pulmonary sleeve resection (PSR) is about 3%. This is slightly less than the estimated mortality of 6% after pneumonectomy.[2]

Post-operative complications require careful evaluation, with imaging playing an important part, including a chest x-ray and computed tomography (CT). Bronchoscopy and esophagoscopy may also be utilized.[9]

In one study comparing pneumonectomy and sleeve lobectomy (SL), the SL outcomes appear to be associated with the pathologic stage of NSCLC.[6] For example, if the resection is N0, survival is 60%, but if the pathologic stage is N1, it falls to 30%.[2]

Some early complications include:[9][17][18]

• Bronchial anastomotic dehiscence 
• Lung/bronchial torsion - mainly involves the RML after RUL
• Pneumonia
• Persistent air leak
• Chylothorax
• Hemothorax
• Wound infection
• Thoracic empyema
• Pulmonary embolism
• Phrenic never palsy or paralysis
• Pulmonary infarction
• Pulmonary hernia through a thoracotomy incision
• Atelectasis requiring bronchoscopy
• ARDS
• Prolonged mechanical ventilation
• Atrial fibrillation

Some late complications include:[9]

• Local tumor recurrence (for lung cancer)
• Bronchial anastomotic stenosis
• Esophagopleural fistula
• Bronchopleural fistula

Bronchial dehiscence is an early complication, which may occur in up to 6% after SL. CT findings can show a defect in the bronchial wall and unresolving extraluminal air and fluid levels.[9] Anastomotic complications can be related to technical failures such as devascularization/ischemia or excessive tension.[12] Induction chemotherapy does not appear to increase anastomotic complications after SL for central NSCLC.[19][20]

Bronchial anastomotic stenosis is a late complication (up to 18%) of PSR.[13]

Local, regional recurrence of tumors was estimated to be 8% in SL than 10% after pneumonectomy; however, this did not adversely affect long-term survival, which an improved 5-year survival noted in the SL group.[21]  

For minimally invasive surgical techniques, preoperative comorbidity, older age, and surgeon's experience have been described as potential risk factors for postoperative complications.[16]

Clinical Significance

Pulmonary sleeve resection (PSR) techniques allow patients with locally advanced lung cancer to undergo surgical resection, otherwise not suitable candidates for pneumonectomy. It is now well recognized that even patients with normal preoperative lung function might benefit from PSR, as compared to pneumonectomy. It is thus an important surgical option for any well-trained thoracic surgeon.[2] Long-term survival and quality of life appear to be improved compared to pneumonectomy.[2][5] Some retrospective comparisons demonstrate early post-operative complications with SL, but long-term disease-free survival rates appear to favor SL when feasible compared to pneumonectomy.[3][18] Thus, the preferred technique for locally advanced lung cancer if anatomically amenable is PSR or SL.[2][10] 

A large meta-analysis demonstrated improved 5-year survival in patients undergoing SL of 50% compared to 30% for pneumonectomy. Improved operative mortality of 3%, compared to 6% for pneumonectomy. Also, the locoregional recurrence of tumors is improved by 17% compared to 30% for pneumonectomy.[5] At least, local recurrence does not seem to be increased for SL compared to pneumonectomy.[2] However, SL may increase the operative duration and increase the extent of bleeding compared to pneumonectomy.[6]  

Recent advances in thoracic surgical procedures have demonstrated that minimally invasive techniques can be applied to perform PSR at certain institutions.[7][8] Caso et al. recently published a small case series demonstrating the feasibility and technical aspects of PSR using minimally invasive thoracic surgical techniques.[7] VATS SL is equally safe and effective compared to the traditional open thoracotomy approach, albeit with a longer operating time.[14][22] Even a small case series of robotic SL for centrally located NSCLC demonstrated equivalent morbidity and mortality and similar oncologic survival, compared to open and VATS.[23][24] With a steep learning curve, more experience will be necessary before using these newer surgical techniques becomes widespread.

Enhancing Healthcare Team Outcomes

An enhanced recovery pathway is recommended for thoracic patients undergoing major resection, including pulmonary sleeve resection (PSR). A multidisciplinary approach to pain control and rehabilitation is key to achieving good surgical outcomes and decreasing complications.[14] [Level 5]

Overall, sleeve lobectomy appears to be safe, effective, and an effective surgical option compared to pneumonectomy for non-small-cell lung cancer (NSCLC) over the past 20 years. Most case series reported are from high-volume thoracic surgical centers with experienced thoracic surgeons and skilled peri-operative teams.[2] [Level 3]

Nursing, Allied Health, and Interprofessional Team Interventions

Surgical resection and reconstruction of the bronchus require an experienced multidisciplinary team of surgeons, anesthesiologists, and operative staff to ensure optimal results. This includes patient selection, planning, and execution.[12] [Level 5]

Nursing, Allied Health, and Interprofessional Team Monitoring

The increasing technical aspect of pulmonary sleeve resection requires a multidisciplinary team educated in the pre-operative, intra-operative, and postoperative intensive care unit necessary for best results. Some aspects requiring excellent communication between all levels of healthcare providers and knowledge include ventilatory modes, hemodynamic assessments, fluid balance, and pain control.[12] [Level 5]

Rapid recognition and management are required for the variety and range of severity of postoperative pulmonary complications.[17] [Level 5]