Overview
Definition:
Carinal resection involves the surgical removal of the carina, the point where the trachea bifurcates into the left and right main bronchi
it is a complex procedure often performed en bloc with the trachea and/or main bronchi, frequently as part of extended resections for centrally located malignancies.
Epidemiology:
Carinal resection is indicated in a small subset of patients with thoracic malignancies, primarily non-small cell lung cancer (NSCLC) invading the carina, but also for adenoid cystic carcinoma of the trachea, esophageal cancer with tracheal invasion, or recurrent tumors
Incidence is low, reflecting the rarity of such extensive local invasion.
Clinical Significance:
This procedure is technically demanding and carries significant morbidity and mortality due to the critical anatomical location of the carina and its intimate relationship with vital structures like the recurrent laryngeal nerves, vagus nerves, phrenic nerves, and major mediastinal vessels
Successful execution requires meticulous planning, multidisciplinary collaboration, and advanced surgical expertise to achieve oncologic clearance while preserving pulmonary function and quality of life.
Indications
Oncologic Indications:
Primary non-small cell lung cancer (NSCLC) involving the carina or requiring en bloc resection of the carinal lymph nodes
Adenoid cystic carcinoma of the trachea with carinal extension
Esophageal cancer with direct carinal or tracheal invasion
Recurrent or metastatic tumors involving the carina.
Non Oncologic Indications:
Benign tracheal tumors or strictures necessitating carinal resection and reconstruction
Severe post-intubation tracheal stenosis involving the carina
Traumatic injury to the carina.
Reconstructive Considerations:
Extent of resection determines the need for reconstruction, ranging from primary anastomosis for limited resections to complex reconstructive techniques using autologous tissues (e.g., pericardial, pleural, fasciocutaneous flaps) or prosthetic materials for larger defects
Consideration of airway patency and physiological impact is paramount.
Preoperative Preparation
Patient Evaluation:
Comprehensive assessment of cardiopulmonary reserve, nutritional status, and comorbidities
Detailed staging of malignancy with CT, PET-CT, and bronchoscopy with biopsy to assess carinal involvement and resectability
Pulmonary function tests (PFTs) are crucial.
Bronchoscopic Assessment:
Rigid bronchoscopy is essential to evaluate the extent of tumor involvement, assess mobility of the carinal plane, and determine the feasibility of resection
Biopsies confirm histology and grade
Assessment for contralateral lung involvement is vital.
Multidisciplinary Team Discussion:
Involves thoracic surgeons, medical oncologists, radiation oncologists, pulmonologists, anesthesiologists, and intensivists
Decision-making regarding neoadjuvant therapy, surgical approach, extent of resection, and reconstructive strategy is collaborative.
Anesthetic Management:
Requires specialized anesthetic techniques, including the use of a double-lumen endotracheal tube or a single-lumen tube with bronchoscopic intubation, high-frequency jet ventilation, and careful hemodynamic monitoring to manage potential intraoperative complications like pneumothorax or tracheobronchial injury.
Surgical Principles And Technique
Approach:
Typically a median sternotomy or a posterolateral thoracotomy (right or left, depending on tumor location)
A combined sternotomy and thoracotomy (clamshell incision) may be necessary for extensive dissections
Minimally invasive approaches are generally not feasible for complex carinal resections.
Dissection Strategy:
Careful dissection of the mediastinal lymph nodes (stations 2, 4, 7, 11)
Mobilization of the trachea and main bronchi proximal and distal to the planned resection
Identification and preservation of critical structures like the vagus and recurrent laryngeal nerves is paramount, though sometimes sacrifice is unavoidable.
Resection Margins:
Achieving negative surgical margins is the primary oncologic goal
For malignant tumors, a margin of at least 2 cm from the gross tumor is desirable
Frozen section analysis of margins is essential during surgery.
Reconstruction Techniques:
Primary tracheobronchial anastomosis is preferred for shorter resections
For longer resections, various reconstruction methods are employed, including direct anastomosis with appropriate tension relief, use of tracheoplasty techniques, or autologous grafts (e.g., pericardial tube, radial forearm free flap, pectoralis flap) to bridge larger gaps
Prosthetic materials are used with caution due to infection risk.
Postoperative Care
Intensive Care Monitoring:
Close monitoring in an ICU setting is required, including continuous pulse oximetry, arterial blood gas analysis, and hemodynamic monitoring
Respiratory support with mechanical ventilation may be necessary initially.
Airway Management:
Securing airway patency is critical
Humidification of inspired air to prevent crusting and mucus plugging
Aggressive pulmonary toilet with suctioning is essential
Chest physiotherapy and incentive spirometry are encouraged
Bronchoscopy may be needed to assess the anastomosis or clear secretions.
Nutritional Support:
Adequate nutritional support, often via enteral feeding tubes (nasogastric or gastrostomy), is crucial for wound healing and overall recovery
Patients with esophageal involvement may require parenteral nutrition initially.
Complication Surveillance:
Vigilant surveillance for anastomotic dehiscence, infection (bronchial stump, mediastinitis), bronchopleural fistula, mediastinal bleeding, vocal cord paralysis, and respiratory compromise
Early identification and management are key.
Complications
Early Complications:
Anastomotic dehiscence, leakage, or stenosis
Tracheobronchial stump dehiscence
Bronchopleural fistula
Mediastinitis
Suture line infection
Hemorrhage
Pneumonia
Acute respiratory failure
Atelectasis.
Late Complications:
Chronic tracheobronchial stenosis
Vocal cord paralysis (if recurrent laryngeal nerve sacrificed)
Recurrent disease
Persistent cough or dyspnea
Poor wound healing
Stricture formation at the anastomosis.
Prevention Strategies:
Meticulous surgical technique, adequate vascularity of the airway margins, tension-free anastomosis, appropriate use of reconstructive materials, judicious use of drains, prompt management of airway secretions, aggressive pulmonary toilet, and appropriate antibiotic prophylaxis.
Prognosis
Factors Affecting Prognosis:
Histological type and stage of malignancy, completeness of resection (R0 vs
R1/R2 margins), need for nerve sacrifice, extent of carinal involvement, patient’s cardiopulmonary reserve, and incidence of postoperative complications
Adjuvant or neoadjuvant therapy can influence outcomes.
Outcomes:
For benign conditions, outcomes can be favorable with successful reconstruction
For malignant disease, long-term survival is highly dependent on achieving complete oncologic resection
Morbidity and mortality rates are significant, with mortality ranging from 5-15% in experienced centers, but can be higher in less experienced hands or for more extensive resections.
Follow Up:
Regular follow-up with clinical examination, bronchoscopy, and imaging (CT scans) is essential to monitor for recurrence, assess airway patency, and manage late complications
The frequency and duration of follow-up are tailored to the individual patient and their underlying condition.
Key Points
Exam Focus:
Carinal resection is a complex procedure for advanced thoracic malignancies involving the carina
Indications include invasive lung, tracheal, or esophageal cancers
Key surgical principles include achieving R0 margins, preserving critical structures, and adequate reconstruction
Postoperative care focuses on airway management and complication surveillance.
Clinical Pearls:
Preoperative bronchoscopy is indispensable for assessing carinal involvement and resectability
Multidisciplinary team approach is vital
Tension-free anastomosis and careful airway management are critical for successful outcomes
Reconstruction strategies vary widely based on defect size.
Common Mistakes:
Inadequate preoperative staging leading to unresectable disease
Failure to achieve negative margins
Excessive tension on the anastomosis
Poor airway management postoperatively
Underestimating the complexity and potential complications
Inadequate reconstruction leading to stenosis or airway compromise.