19

Combined bronchial and pulmonary artery sleeve resections

Abel GÓmez-caro and Laureano Molins

INTRODUCTION

In centrally located lung cancer, resection is frequently associated with massive parenchyma extirpation and high rates of morbidity and mortality. Pneumonectomy (PN) has a significantly greater incidence of mortality compared with lesser pulmonary resections and results in substantial declines in lung function and quality of life, precluding adjuvant treatments or further lung resection. In the search for alternative strategies, sleeve lobectomy (SL) has become the gold standard for centrally located lung tumors that otherwise would not be resectable by simple lobectomy. Sparing lung function may allow patients with very limited lung function and those treated with chemoradiotherapy to overcome prohibitive surgical risk and be candidates for intervention. About 10%–14% of all lung tumors and nearly 60% of central tumors may be amenable to sleeve resection with combined pulmonary artery (PA) and bronchial reconstruction techniques. Several thoracic surgery teams have developed an aggressive parenchyma-sparing policy, with a reported PN:SL ratio of at least 1:3, decreasing the PN rate to 5%.

Management of centrally located non-small-cell lung cancer may combine various surgical techniques to avoid PN without compromising the long-term oncological results. Surgical options include PA reconstruction or replacement, alleviation of bronchial mismatch, and in some cases, resection of more than one lobe and airway anastomoses in segmental bronchi.

PREOPERATIVE EVALUATION

Preoperative assessment of potential surgical candidates includes taking the clinical history; performing a physical examination; standard blood tests; chest radiographic analysis; bronchoscopy; and thoracic, abdominal, and cerebral computed tomography scan, as well as 18F-fluoro-D-glucose positron emission tomography. Suggestion of ipsilateral mediastinal lymph node metastases (N2 disease) requires histologic confirmation using the most appropriate invasive methods; if confirmed, neoadjuvant treatment is needed before the candidate can be considered for resection, based on response to therapy. Functional tolerance of PN must be established before SL can be attempted. In very carefully selected cases with high probability of complete resection without neoadjuvant therapy, the SL strategy could be considered even with poor lung function that precludes PN. The predicted postoperative forced expiratory volume in 1 second is estimated either with the 19-segment method, which multiplies baseline function by the percentage of lung segments that remain after resection, or with isotopic scanning where needed.

ANESTHESIA

Systematic bronchoscopy is done before surgery and repeated in theater by the operating surgeon to assess intraluminal tumor extension from segmental or main bronchi in order to macroscopically anticipate the potential site of anastomoses. If laser or mechanical resection is needed, rigid bronchoscopy should be performed. Double-lumen tube intubation is preferred over a bronchial blocker in these operations. If extended SL (lobe plus one or two segments) is carried out, jet ventilation may be employed if desaturation occurs during the procedure and is useful to identify the segmental plane if extended SL is needed. Epidural catheterization is routinely used, if not contraindicated, to improve postoperative care and physiotherapy. Antibiotics may be started if there is evidence of ongoing infection; if not, regular prophylactic protocol is followed.

SURGICAL TECHNIQUE

Posterolateral thoracotomy with or without serratus dorsi muscle sparing is the preferred approach. Comfortable and excellent exposure is essential for technically demanding procedures such as bronchial and PA reconstruction. If vascular reconstruction is required positioning the clamps also requires adequate exposure and precise surgical technique, following accepted vascular principles in order to avoid postoperative anastomotic complications.

1. During thoracotomy, if bronchovascular reconstruction is planned, an intercostal flap including the parietal pleural is harvested and preserved before any rib spreading, to be used to cover the anastomosis and to separate the PA and bronchial sutures. An exploration of the thoracic cavity is completed before performing any irreversible steps in the procedure. Technical and oncological feasibility of the parenchymal-sparing technique is evaluated preoperatively in the outpatient clinic, with the final decision made by the surgeon during the procedure.

Left-side double-sleeve resection

PA reconstruction—lateral resection, end-to-end anastomoses, patch reconstruction, or replacement—is most frequent on the left side (60%-70% of cases), mainly because of the short left main PA and its relation to the mainstem bronchus. Lateral PA resection, patches, or end-to-end anastomoses may be performed on the right side, but replacement by conduit is rarely required. In general, lateral resection is performed when the branch take-off or less than 25% of the PA caliber is tumor involved. Although lateral clamping is the simplest procedure, systemic heparin and central clamping are safer and more easily achieve an adequate artery caliber and healthy anastomosis. When more than about a third of the artery is involved, reconstruction should be performed using either a patch (autologous or bovine pericardium, autologous vein, etc.) or end-to-end anastomosis, depending on the surgeon’s experience or preferences. In our experience, end-to-end anastomosis tends to be preferred because it is simple, quick, and easily performed along with the bronchial sleeve resection. A long artery segment invaded by the tumor may require PA replacement with biological conduit (see Figure 19.1).

1. On either side, when the PA is involved, intrapericardial control of the main PA should be achieved. Lymph nodes of the aortopulmonary window may complicate the main artery and bronchus dissection. The superior pulmonary vein is encircled intraor extrapericardially and divided, allowing full exposure of the proximal PA and better exposing the artery to permit optimal clamp placement for proximal control. The left main PA is clamped as far proximally as possible, with distal control achieved by clamping the artery within the fissure. Fused fissures and inflamed tissues are frequent in these cases, and may result in persistent postoperative air leak that can cause concern regarding anastomotic failure. Careful surgical technique is required to avoid this problem, allowing the surgeon to sleep better at night. These central tumors usually extend throughout the fissure and may involve the superior segment of the lower lobe. When an extended SL (lobe plus one or two segments) is required, the intersegmental plane must be identified, with or without the use of jet ventilation in order to complete the anatomic segmentectomy. The segments involved are removed en bloc with the lobe by developing the intersegmental plane, usually with electrocautery and scissors. We avoid the use of mechanical staplers in order to optimize reexpansion of remnant lung in an attempt to fill the entire thoracic cavity. Once the specimen is removed, the raw surface of the lung parenchyma is checked for bleeding and air leaks and may be reinforced with pulmonary sealant (see Figure 19.2 ).
   
2. When the PA segment is involved by the tumor (<25% of all sleeve reconstructions), it must be resected en bloc with the specimen. Systemic heparin sodium (5000 units/h) is intravenously administered before any PA clamping and not reversed during operation. Soft atraumatic vascular clamps are used on the proximal PA (Satinsky curve clamp) and distal (bulldog or femoral clamp) disease-free segments of the PA. Proximal clamp placement must provide sufficient space to allow for construction of the anastomosis. If an extensive PA reconstruction is planned, division of the ligamentum arteriosum prior to placing the proximal clamp greatly facilitates mobilization of the proximal portion of the PA, leaving enough space for the anastomosis. The phrenic and vagus nerves and, specifically, the left recurrent laryngeal nerve should be identified and preserved, if possible, but there should be no hesitation in sacrificing these structures if doing so will permit a complete resection. Ideally, one should avoid taking both the phrenic and the vagus nerves. If resection of the vagus nerve is necessary, one should try to take it distal to the take-off of the left recurrent laryngeal nerve. To avoid injuries after both anastomoses are complete, systematic mediastinal dissection with en bloc lymph node resection of station 7 is performed before the reconstruction and clamping (see Figure 19.3 ).
   
3. Once the fissure is opened, the PA and bronchus are circumferentially divided using a scalpel. The distal bronchial opening is always close to the origin of segmental bronchi (if not oncologically precluded); a trapezium-like section, involving less of the distal bronchus wall, is recommended to minimize the tension of the anastomoses (see Figure 19.4a). Bronchial and arterial margins are assessed routinely by frozen section to ensure R0 resection. The bronchial anastomosis should be performed prior to the vascular reconstruction. En bloc resection of the tumor, lung parenchyma, and PA is performed. The PA section should be placed at least 5 mm distal to the proximal clamp to allow for construction of the anastomosis (see Figure 19.4b).
   
4. Avoidance of excessive tension on both the bronchial and vascular anastomoses is essential and should not be a problem. Bronchial tension can be decreased with several maneuvers, including the routine use of division of the inferior pulmonary ligament. A U-shaped pericardial release incision around the inferior pulmonary vein allows for an extra 1–2 cm and causes no additional morbidity. If necessary for better exposure, rolled packing can be placed at the bottom of the thoracic cavity to lift the lower lobe and facilitate anastomosis. If tension tears the tissues (damaged by inflammation, previous chemoradiotherapy, fissure dissection, etc.) during PA anastomoses, a PN or PA replacement should be considered at this stage. Completion PN in a reoperation has a high incidence of complications and mortality. Bronchus manipulation must be very gentle to protect the tissues and bronchial blood supply. Use of the electrocautery of surrounding tissues should be avoided and bronchial arteries must be spared during dissection and lymphadenectomy. The bronchial anastomosis is begun on the membranous aspect using an absorbable monofilament 4-0 suture with a double needle. The initial stitch is placed in the middle of the membranous portion of the distal bronchial segment and main bronchus to avoid torsion of the bronchial axis, with running suture leading away from the surgeon until the cartilaginous junction. The other needle is used at this point and membranous portion is completed. Corner stitches are placed and tension of the running suture is checked and tied with the knots outside. The first stitch (again, double needle and absorbable monofilament 4-0) is placed at the middle of the cartilaginous portion and the anastomosis is completed by interrupted stitches every 2–3 mm, alternating sides to avoid telescoping. The cartilage sutures should encompass the entire bronchial wall and involve approximately a 3–4 mm length of bronchus to ensure a solid anastomosis (see Figure 19.5 ). Extremely large caliber discrepancies between the proximal and distal bronchial segments are uncommon in routine SL, but are a frequent finding in extended SL. These can be reconciled by narrowing the proximal stump by passing 4-0 absorbable monofilament sutures through the membranous portion and adjacent ends of the stump’s cartilaginous ring to achieve plication and substantial narrowing. We prefer this small variation over telescopic suture, which could result in healing problems during the postoperative course. In general, we consider this hybrid anastomosis (running and interrupted suture) quicker, safe, and equivalent to using all interrupted sutures to adjust the caliber discrepancies. After filling the thoracic cavity with saline, we routinely check the suture line for air leaks using a peak airway pressure of 30 mmHg, and we perform bronchoscopy prior to leaving theater. Any air leak on the bronchial suture should be reinforced using interrupted sutures, ignoring the needle hole leaks. If the bronchial anastomosis is not perfect, this is the moment to redo or correct. A few hours or days later, correction will be more difficult for both the surgeon and the patient (see Figure 19.5a and b).
   
5. PA anastomoses are performed using systemic and local heparin to avoid in situ thrombosis. If distal clamping is very tight after bronchial anastomosis, the clamp can be removed and the inferior pulmonary vein can be clamped discontinuously to avoid intralobar venous thrombosis. After 20 minutes, when the bulldog clamp is removed, there is very little backflow due to the surgical atelectasis, and distal anastomosis can be carried out without further maneuvers. End-to-end anastomosis is started using a nonabsorbable monofilament 5-0 to 6-0 running suture, beginning in front of the principal surgeon and at the bottom of the anastomosis. The PA is then refilled by local heparin-saline and the proximal clamp is partially opened to allow 25%-50% flow reperfusion, while a gentle ventilation of the spared lobe quickly enhances lung perfusion. The anastomosic suture is tied after air purge during the low-flow reperfusion, and the clamp is totally removed after 10-15 minutes. A pedicled intercostal flap is used to wrap the bronchial anastomoses and split vascular anastomoses, especially in the case of a double sleeve, large caliber discrepancies, and neoadjuvant chemoradiotherapy. Close surveillance of the spared lobe is needed during closing to detect thrombosis or any other technical complications. As the PA is a low-pressure system, a small arterial leak may go unnoticed in the operating room. In our experience, postoperative anticoagulation or antiplatelet therapy is not needed for PA reconstruction when using biological materials; we start it only when indicated because of associated diseases (see Figure 19.6 ).

Stay updated, free articles. Join our Telegram channel

Join