Overview
Definition:
A segment 5/8 wedge resection is a surgical procedure involving the removal of a wedge-shaped portion of the lung parenchyma that includes segments 5 and 8 of a lung lobe
Segment 5 is the anterior basal segment, and segment 8 is the superior segment of the lower lobe
This procedure is a form of lung-sparing surgery, typically performed for smaller peripheral lung lesions when a lobectomy or pneumonectomy is not indicated or desired
It aims to excise diseased tissue while preserving as much functional lung as possible.
Epidemiology:
The frequency of segment 5/8 wedge resections is dictated by the incidence of peripheral lung lesions amenable to this limited resection
These lesions often represent early-stage lung cancers, benign tumors, or localized inflammatory processes
Data specific to the epidemiological burden of conditions requiring precisely a 5/8 segmentectomy is not typically tracked separately from other limited resections.
Clinical Significance:
Segment 5/8 wedge resection is crucial for managing select cases of lung malignancy where cure can be achieved with minimal lung volume loss
It is particularly important for patients with compromised pulmonary function who may not tolerate a more extensive resection like a lobectomy
The goal is to achieve oncologic control while optimizing post-operative respiratory function, a key consideration for patient outcomes and quality of life.
Indications
Surgical Indications:
Indications include solitary pulmonary nodules suspicious for malignancy in patients with marginal pulmonary reserve
Stage IA non-small cell lung cancer (NSCLC) with a size ≤ 2 cm, lacking high-risk features
Recurrent or metastatic disease confined to segment 5 or 8
Benign lung tumors or cysts
Localized infectious processes unresponsive to medical therapy.
Patient Selection:
Careful patient selection is paramount
Patients must have a clearly defined lesion primarily confined to segments 5 and 8
Assessment of pulmonary function (spirometry, DLCO) is essential to determine suitability for lung resection
Cardiac status and overall comorbidity burden must be evaluated to ensure operative safety.
Contraindications:
Absolute contraindications include unresectable disease, extensive metastatic disease, or significant cardiopulmonary compromise that would preclude any surgical intervention
Relative contraindications may include poorly defined lesions extending beyond the target segments or inability to achieve negative margins.
Preoperative Preparation
Imaging Assessment:
Preoperative imaging, including CT scan with contrast and PET-CT, is vital to define the lesion, its relationship to bronchi and vessels, and to rule out nodal involvement or distant metastases
Bronchoscopy may be performed to assess the airway and obtain biopsies.
Pulmonary Function Tests:
Pulmonary function tests (PFTs) are mandatory to assess predicted postoperative lung function
Forced expiratory volume in 1 second (FEV1) and diffusion capacity of the lungs for carbon monoxide (DLCO) are key parameters
Predicted postoperative FEV1 and DLCO are calculated to estimate functional reserve.
Medical Optimization:
Patients should be counseled on smoking cessation
Optimization of medical conditions such as COPD, heart failure, and diabetes is crucial
Nutritional assessment and support may be necessary for malnourished patients.
Informed Consent:
Thorough discussion with the patient and family regarding the procedure, potential risks and benefits, alternative treatment options, and the possibility of conversion to a more extensive resection (e.g., lobectomy) if intraoperative findings warrant it.
Procedure Steps
Surgical Approach:
The procedure can be performed via thoracotomy (open) or video-assisted thoracoscopic surgery (VATS)
VATS is increasingly preferred due to less postoperative pain, shorter hospital stays, and faster recovery
VATS involves small incisions for instruments and a camera.
Anatomic Segmentation:
Accurate identification of the segmental anatomy of the lower lobe is critical
Bronchi and pulmonary vessels supplying segments 5 and 8 are meticulously dissected and ligated
Anatomical knowledge is key to prevent unintended resection of healthy lung tissue.
Resection Technique:
A wedge-shaped portion of lung tissue containing the lesion is resected
The margins are typically inked to ensure clear boundaries
Stapling devices are commonly used for hemostasis and airway closure
For smaller lesions, careful dissection and suture closure may be employed.
Airway And Vascular Control:
Systematic ligation and division of the segmental bronchus and accompanying pulmonary artery branches for segments 5 and 8 are performed prior to parenchymal transection
Careful attention is paid to venous drainage.
Closure:
After adequate hemostasis and air leak assessment, chest tubes are placed for drainage and lung re-expansion
The chest wall incisions are closed in layers.
Postoperative Care
Pain Management:
Aggressive pain control is essential to facilitate early mobilization and deep breathing exercises
Multimodal analgesia, including patient-controlled analgesia (PCA), epidural analgesia, or regional blocks, is often utilized.
Pulmonary Toilet:
Early mobilization, incentive spirometry, and effective coughing techniques are crucial to prevent atelectasis and pneumonia
Chest physiotherapy may be beneficial.
Chest Tube Management:
Monitoring chest tube output and drainage system function is important
Chest tubes are typically removed when drainage is minimal and there is no air leak.
Monitoring:
Close monitoring of vital signs, oxygen saturation, respiratory rate, and urine output
Daily assessment of wound status and lung sounds
Early detection and management of complications are prioritized.
Complications
Early Complications:
Air leak (prolonged air leak > 5-7 days)
Hemorrhage or bleeding
Infection (pneumonia, empyema)
Atelectasis
Bronchopleural fistula
Persistent air leak
Injury to adjacent structures.
Late Complications:
Chronic pain
Scarring
Recurrence of malignancy
Respiratory insufficiency due to extensive resection or underlying lung disease.
Prevention Strategies:
Meticulous surgical technique, including secure stapling and ligation of airways and vessels
Careful patient selection to avoid excessive resection in compromised individuals
Prompt management of air leaks with chest tube suction and, if necessary, bronchoscopic intervention or reoperation
Postoperative physiotherapy and pain control.
Prognosis
Factors Affecting Prognosis:
For malignant lesions, the most critical factors are the tumor stage, histological type, and achievement of negative surgical margins
For benign lesions, prognosis is generally excellent
Patient comorbidities and overall pulmonary reserve also significantly impact long-term outcomes.
Outcomes:
For early-stage NSCLC, a segmentectomy (including wedge resection) can achieve oncologic outcomes comparable to lobectomy in selected patients, particularly with VATS
For benign conditions, recurrence is rare after complete excision.
Follow Up:
Postoperative follow-up typically involves regular clinical visits and imaging (chest X-ray, CT scan) to monitor for recurrence or complications
The frequency and duration of follow-up depend on the pathology and stage of the disease
For malignancy, oncologic follow-up protocols are strictly adhered to.
Key Points
Exam Focus:
Understand the indications for limited resection vs
lobectomy
Differentiate segment 5 from segment 8 anatomy
Recognize the importance of PFTs in patient selection
Be aware of common complications like prolonged air leak.
Clinical Pearls:
In VATS, intraoperative identification of segmental bronchi and vessels is facilitated by lung inflation maneuvers and dissection
For suspected malignancy, always confirm negative margins intraoperatively if possible
Consider recurrence risk when deciding on follow-up imaging.
Common Mistakes:
Resecting beyond the intended segments due to poor anatomical knowledge
Inadequate management of air leaks, leading to prolonged hospitalization
Not performing adequate PFTs, leading to postoperative respiratory failure
Over-resection in patients with limited pulmonary reserve.