A surgical incision opens an aperture into the thorax to permit the work of the planned operation to proceed. If placed correctly, the operation proceeds with unimpeded visualization of the important anatomy. If placed incorrectly, it can lead to frustrating delays and difficulty in the operation. Dr. Robert E. Gross’ admonition, “If an operation is difficult, you are not doing it properly,” applies directly to the incision used.^* This chapter is designed for both the novice and those who have already gained some experience with thoracic incisions. The artwork is designed to explain important relationships for the inexperienced. We also have provided subtle pearls that will rekindle an appreciation of different incisions for the more experienced. More important, we have tried to explain the logic behind the incisions.

Each incision is described in terms of its current general use, technical details, advantages, and disadvantages. We also provide details of chest wall anatomy, with particular attention to structures that can be injured while developing the incision. Finally, we provide surface anatomy landmarks that can be used to place the incision properly.

As the thoracic surgeon gains experience, these incisions frequently will be modified to accommodate the primary surgical objective of a given operation. Furthermore, as technology progresses, these standard incisions may begin to change. For instance, in the modern era of video-assisted techniques, even classic open incisions are decreasing in length as surgeons become more comfortable with the concept of centering the incision on the anatomy that is critical for the operation to progress. In this regard, these standardized incisions can be thought of as building blocks, similar to the notes of a musical chord. It is our belief that the more the surgeon understands the strengths, weaknesses, and possibilities of each incision, the quicker he or she will learn to use the full variety of possible incisions tailored to the individual patient.

General Use

Posterolateral thoracotomy is the standard workhorse for most thoracic surgeons. It offers excellent direct visualization of the entire thoracic cavity, including the posterior diaphragmatic sulcus and apex of the hemithorax. The incision generally is centered over the fifth intercostal space, which corresponds to the greater fissure of the lung. This provides an unobstructed view of the base of the fissure, the pulmonary artery, and the hilum. The incision generally is used for anatomic lung resections, including pneumonectomy and lobectomy. It offers the easiest access for radical lymphadenectomy. An extended posterolateral thoracotomy is used for Pancoast resection, extrapleural pneumonectomy, and aortic transection.

Technique

The patient is placed in a standard lateral decubitus position, with the ipsilateral arm extended forward. The inferior tip of the scapula is palpated and generally marked. The incision begins approximately 3 cm posterior to the scapula tip and approximately halfway between the scapula and the spinous process. The incision curves around the tip to lie along the top margin of the sixth rib (fifth intercostal space). In general, it extends to the anterior axillary line (Fig. 2-1). The soft tissue and Scarpa’s fascia are divided. The latissimus dorsi muscle is divided. The auscultatory triangle, the space bounded by the lower border of the trapezius, the serratus anterior, and the medial margin of the scapula can be identified at this time. The serratus anterior muscle can be spared by freeing it from the soft tissue of the auscultatory triangle and the muscle rotated forward. Preservation of the serratus anterior muscle helps to preserve the motion of the shoulder girdle and quickens recovery time. An intact serratus anterior muscle can limit the spread of the fifth and sixth ribs. This can be overcome by detaching the lower slips of attachment of the muscle from the eighth, seventh, and sixth ribs (Fig. 2-2).

If the ribs are to be preserved, the attachment of the intercostal muscles is divided from the top of the sixth rib. It is important to stay on the top surface of the lower rib to avoid injury to the neurovascular bundle of the upper rib. This is best done by proceeding from posterior to anterior along the line of the external intercostal fibers. For maximal spread of the ribs, it is important to take down these attachments as far forward as the costochondral junction and as far posterior as the transverse processes of the vertebral body. Both these landmarks can be palpated by a finger passed just superficial to the intercostal muscle layer. In general, there is no need to disrupt the erector spinae ligament, which passes perpendicular to the posterior rib behind the posterior axillary line.

Either removing the rib or “shingling” the posterior rib can achieve additional spread of the ribcage. To remove the rib, the periosteum is raised initially by cautery, and then the plane between the cortical bone and the periosteum is dissected with a periosteal elevator. The neurovascular bundle is pushed out of the inferior groove of the rib with the elevator. The elevator is passed from posterior to anterior above the rib and from anterior to posterior below the rib to take advantage of the angle of the superficial intercostal muscle fibers as they insert into the bone. The direction of these fibers can be remembered simply by thinking of the angle of your arm when you place your hand in your pocket. After the periosteum is raised, the rib is cut, usually with a guillotine rib cutter. This device cuts the bone to one side and thus needs to be turned to remove the entire stripped portion of bone.

“Shingling” a rib involves removal of approximately a centimeter length of rib just anterior to the erector spinae ligament to allow further distraction of the fifth and sixth ribs without a subsequent midshaft fracture of the rib (Fig. 2-3). These small bony defects are much less painful than midshaft fractures. It is important to free the intercostal neurovascular bundle from beneath the inferior groove of the posterior segment of the remaining rib to prevent neuropraxia of the nerve. Increasing the distraction of the ribs can stretch the nerve if it remains fixed to the undersurface of the posterior fragment. Freeing this nerve provides additional visualization of the thorax without nerve injury. Closure begins with placement and securing of chest tubes. Paracostal sutures then reapproximate the spread ribs. If no rib has been taken, generally four sutures suffice. If a rib has been removed, six to eight sutures are commonly required to prevent a chest wall hernia. If a midshaft rib fracture has occurred, the paracostal sutures should be placed to prevent movement of the fracture. Fracture ends sometimes are best treated by removing the jagged portion of the rib with a rib cutter, with the end result similar to a “shingle.” The ribs should be approximated but not brought tightly in apposition to each other because this frequently causes the bones to fuse subsequently, which can limit surgical choices for redo thoracotomies. The serratus anterior muscle is reapproximated to the soft tissue overlying the auscultatory triangle, and then the latissimus dorsi muscle is sewn back together. Approximation of the latissimus dorsi fascia with minimal bulky muscle will minimize pain and provide a superior cosmetic result. Two additional layers of closure reapproximate Scarpa’s fascia and the skin.

Advantage

The posterolateral thoracotomy incision provides the best unobstructed view of the entire hemithorax (Fig. 2-4).

Disadvantages

A generally long incision, the posterolateral thoracotomy is associated with more tissue injury to the extrathoracic musculature and soft tissue. It is also associated with a longer recovery time than almost any other incision (with the exception of the clamshell incision, which is generally slightly more morbid). It takes more time to open and close this incision compared with minimally invasive incisions. Epidural catheters have improved acute postoperative pain control and are especially helpful in the face of impaired lung function.

Chest Wall Anatomy

Key bony landmarks (Fig. 2-1) include the tip of the scapula,¹ the sixth rib (identified as the first rib contributing to the costal margin), the fifth rib (identified as the last rib inserting directly on the sternum), the erector spinae ligament, the costochondral junction, and the transverse process of the sixth vertebral body. Soft tissue landmarks include the latissimus dorsi muscle (innervated by the thoracodorsal nerve) and the serratus anterior muscle originating from the eighth to second ribs and innervated by the long thoracic nerve. A small vascular perforator enters each of the slips of the serratus anterior muscle where they insert on the rib. Both the thoracodorsal nerve and the long thoracic nerve can be injured. Ribs can be fractured if the distraction exceeds the ability of the rib to displace owing to muscle attachments.

Surface Landmarks

Tip of the scapula, the xiphoid tip, the costal margin, the sixth rib insertion onto costal margin, the fifth rib insertion into the sternum, the anterior border of the latissimus dorsi muscle, and the posterior border of the pectoralis major muscle.

General Use

Although a popular incision in the 1950s for upper lobectomy, the anterolateral thoracotomy was supplanted subsequently by better visualization afforded by posterolateral thoracotomy. Video-assisted techniques have spawned a rekindled interest in this incision. It provides excellent visualization for middle lobectomies and work within the anterior chest. It is smaller and better tolerated than a full posterolateral thoracotomy. Furthermore, small utility incisions used for video-assisted thoracic surgery (VATS) lobectomy can be converted easily to a more conventional anterolateral thoracotomy for quick improvements in visualization without resorting to a posterolateral thoracotomy.

Technique

These incisions generally are placed in the fourth or fifth intercostal space (Fig. 2-5). The fourth interspace (over the top of the fifth rib) provides excellent visualization of the anterior mediastinum and hilum at the level of the superior pulmonary vein. The fifth intercostal space (over the top of the sixth rib) provides better visualization for a middle lobectomy because it provides visualization of both the lower portion of the superior pulmonary vein and the top portion of the inferior pulmonary vein (Fig. 2-6).

The patient is placed in the same lateral decubitus position as for a posterolateral thoracotomy. The arm is placed in a more classic “swimmer” position with 90-degree abduction of the upper arm to allow easier access to the fourth intercostal space.

The incision starts approximately 1 cm posterior to the pectoralis major muscle and runs along the top of the rib for approximately 10 to 15 cm. The skin and Scarpa’s fascia are divided. The posterior border of the pectoralis major muscle is frequently seen but not divided. The latissimus dorsi muscle is not seen. The serratus anterior muscle is divided along the course of its fibers and not rotated. The intercostal muscle is lifted from the top of the inferior rib. The intercostal muscle can be further undercut beneath the more superficial soft tissues by bluntly developing a plane just superficial to the intercostal muscle and then dividing it while not dividing the more superficial soft tissues. It is important to remove the intercostal muscle from the top portion of the lower rib to avoid injury to the neurovascular bundle of the upper rib. Although ribs can be removed or “shingled,” this is rarely needed because the intercostal space gets larger as the ribs pass anteriorly. Thus there is a greater natural distraction of ribs at the anterior axillary line compared with the posterior axillary line.

Advantages

The anterolateral incision is smaller and associated with a quicker recovery compared with the posterolateral incision. The latissimus dorsi muscle is not divided, leaving better shoulder function postoperatively and preserving future use of a latissimus dorsi flap if the patient is at risk of developing a bronchopleural fistula.

Disadvantages

Although the incision provides good visualization of the anterior hemithorax, visualization of the posterior hemithorax and inferior portions of the chest are impaired. These disadvantages can be offset by the use of thoracoscopy, hence the frequent use of this incision in VATS procedures. Quick extension of the incision is hampered by the potential of injury to the long thoracic nerve posteriorly and the bulk of the pectoralis major muscle anteriorly.

Chest Wall Anatomy

Key bony landmarks include the sixth rib (identified as the first rib contributing to the costal margin), the fifth rib (identified as the last rib inserting directly on the sternum), and the costochondral junction. The most important soft tissue landmark is the long thoracic nerve that innervates the serratus anterior muscle and runs just beneath the anterior border of the latissimus dorsi muscle. Since the serratus anterior muscle is divided along its fibers and not rotated, this nerve can be injured by posterior extension or misplacement of the incision.

Surface Landmarks

Posterior border of the pectoralis major, the sixth rib insertion onto the costal margin, the fifth rib insertion into the sternum, and the anterior border of the latissimus dorsi muscle.

General Use

An axillary thoracotomy can be thought of as an anterolateral thoracotomy incision in the first, second, or third interspace (Fig. 2-7). It provides access to the apex of the hemithorax and is particularly useful for mobilizing a scarred apical segment from the parietal pleura during thoracoscopic procedures,² visualization of the posterior portion of the apex of the lung during bullectomy, and mobilization of the thymus when using a thoracoscopic approach. Because the apex of the lung lacks the bulk of the lower portion, it is easily displaced, and the anterior, middle, and posterior upper mediastinum can be visualized easily. This same incision is used for first rib resection via an axillary approach.

Technique

The ipsilateral arm needs to be put into true swimmer’s position, with a 90- to 120-degree angle between the thorax and the humerus. Deep palpation of the axilla should identify the second and third intercostal space and even the first intercostal space in very thin patients. In general, the third intercostal space between the third and fourth ribs is the easiest position for this incision in males and the second intercostal space in females. The incision extends across the base of the axilla, between the anterior border of the latissimus dorsi muscle and the posterior extent of the pectoralis major muscle. This is the auscultatory triangle. It has no underlying muscles. It contains clavipectoral fascia and underlying lymphatics and lymph nodes. It is important to ligate or cauterize these lymphatics to avoid postoperative lymphoceles. Once one enters the thorax, the incision lies to the anterior side of the hilum at the level of the azygos–caval junction (Fig. 2-8). This is one rib interspace above the superior pulmonary vein.