2: Thoracic Incisions

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.

Advantages

This approach provides adequate visualization of the upper mediastinum and posterior portion of the apex of the lung. Recovery time is very quick, and pain is modest. In general, the higher the interspace, the lower is the pain, most likely because there is less excursion of the ribs during respiration. Maximum excursion of the ribcage during forced respiration is at the level of the seventh and eighth ribs.

Disadvantages

The correct interspace for the incision needs to be considered carefully based on the goal of the operation. A second interspace incision will not allow proper visualization of the superior pulmonary vein. Incisions in the upper interspaces also do not allow much extension of the incision, if desired. Thoracoscopy can be used to place the incision, guided by direct inspection of the surface lung landmarks correlated with soundings at the skin level. This thoracoscopic port then can be used for chest tube placement at the conclusion of the procedure.

Chest Wall Anatomy

The major structures in danger of injury are the long thoracic nerve to the serratus anterior muscle, the thoracodorsal nerve to the latissimus dorsi muscle, and the intercostobrachial nerve (Fig. 2-7). The long thoracic nerve can be identified as it passes under the axillary vein at the level of the second rib. It travels inferiorly along the serratus anterior muscle parallel with the lateral thoracic artery. The thoracodorsal nerve can be identified posterior to the long thoracic nerve, just anterior to the border of the latissimus dorsi muscle. The higher the interspace chosen, the shorter is the length of the bordering ribs, and the higher is the probability of injury to these nerves, especially if the incision is extended posteriorly. If the incision is placed in the first intercostal space, the intercostobrachial nerve also can be injured, resulting in numbness to the medial side of the arm.

Surface Landmarks

Surface landmarks include the anterior axillary fold, which is the posterior border of the pectoralis major muscle, and the posterior axillary fold, which is the anterior border of the latissimus dorsi muscle. The entire axillae should be included in the skin preparation. The inferior edge of the hairline is often the superior extent of any incision.

General Use

This incision is used in rare circumstances where broad exposure is needed within both hemithoraces simultaneously (Fig. 2-9). Examples include double lung transplant, removal of bulky anterior mediastinal masses with lateral extensions beyond the midclavicular lines, and removal of bilateral multiple suspected metastases.³

Technique

The patient is placed supine on the OR table with rolls placed beneath the thorax in the shape of the letter I. This lifts the torso and allows extension of the incision toward the bed. The arms are extended above the head and suspended with the upper arms distracted from the thorax at approximately a 120-degree angle. The incision runs beneath each inframammary crease and crosses the sternum in the fourth intercostal space. The incision extends into the inferior portion of each axilla. The pectoralis major muscle is lifted off the top of the fifth rib anteriorly. The intrapleural space is entered by dividing the intercostal muscles at the midclavicular line. Dissection then extends medially on both sides to the level of the internal mammary vessels. These vessels lie just deep to the deep intercostal muscle and usually can be identified and clipped before division. If injured prior to control, a finger within the intercostal defect can compress the vessel against the anterior chest wall until the sternum is divided. The internal mammary stumps then can be oversewn more securely under direct vision. All adhesions between the thymus and the sternum are divided. Rib spreaders are placed on each side and often can be opened as far as possible.

Closure requires multiple paracostal sutures to reapproximate the fourth and fifth ribs. A no. 5 surgical steel wire in a figure-of-eight pattern is used to reapproximate the sternum. The pectoralis major muscle is sewn back onto the fifth rib. Scarpa's fascia and skin make up the final two layers.

Advantages

This approach provides the most extensive access of any thoracic incision to both hemithoraces and the anterior and midmediastinum. It provides better exposure of the thorax lateral to the midclavicular line than a median sternotomy and often can provide an important lateral angle of the midmediastinum when resecting a bulky tumor.

Disadvantages

Because this incision is associated with extensive disruption of muscle and bone, as well as extended length, recovery from this incision is more difficult than with all other thoracic incisions. Furthermore, the disruption of the intercostal and accessory muscles of respiration at the level of the fourth and fifth interspaces has a serious impact on chest wall excursion and breathing mechanics. As a result, this incision should not be considered for frail patients. Both the phrenic nerves are susceptible to injury, especially when mobilizing adhesions close to their insertions in the diaphragm or at the level of the manubrium. In addition, it provides poor exposure of the posterior mediastinum.

Chest Wall Anatomy

Important landmarks include clear identification of the fourth, fifth, and sixth ribs and their insertions into the sternum or costal margin. The sternomanubrial junction, or angle of Louis, denotes the second intercostal space.

Surface Landmarks

The incision runs through the inframammary crease but must cross the sternum at the level of the fourth intercostal space. Once the pectoralis major muscle has been lifted, the fourth intercostal space is easily brought into the base of the wound, but the skin incision should cross the sternum at the level of the planned osteotomy.

General Use

This incision is used widely for cardiac surgery, resection of anterior mediastinal masses, radical thymectomies, and dissections of the upper mediastinum. It also can provide access to both hemithoraces for bilateral pulmonary nodules or lung volume reduction surgery.

Technique

The most important goal of this incision is to be precisely in the vertical midline of the sternum. This begins with positioning on the OR table. The patient must be supine with a transverse roll beneath the most kyphotic portion of the back. The hips must be even. The sternal notch and tip of the xiphoid are marked, and vigorous palpation of the edge of the sternum in each intercostal space is used to mark the midline of the sternum. The skin incision should extend from the sternomanubrial junction to 2 cm below the tip of the xiphoid (Fig. 2-10). Dissection is carried down through Scarpa's fascia between the origins of the two pectoralis major muscles. Dissection is extended above the sternal notch. A transverse venous branch frequently crosses the sternal notch and should be cauterized. The clavicular– clavicular ligament can be palpated just deep to the undersurface of the manubrium and links the two heads of the clavicles. This is divided with cautery. The linea alba is divided for 2 cm caudal to the tip of the xiphoid process. A second transverse venous branch is found at the sternoxiphoid junction and needs to be cauterized. The surgeon passes a finger through the defect in the linea alba deep to the xiphoid to bluntly open the diaphragmatic hiatus directly behind the sternum. Likewise, the surgeon's finger passes deep to the manubrium at the cranial end of the incision to bluntly dissect the tissue away from the back of the bone (Fig. 2-11). The saw footplate is placed deep to the bone and pushed or pulled through the center in a careful, steady fashion.

Hemostasis is achieved by cauterizing the edges of the periosteum and the application of either bone wax or a topical coagulant, such as Gelfoam, soaked in thrombin. A sternal retractor then is placed.

At the conclusion of the procedure, mediastinal drainage tubes are placed through the rectus sheaths with care not to injure abdominal organs. The bone remnants are reapproximated with surgical steel wire. Generally, no. 5 wire is used. Most commonly, two simple wires are placed in the manubrium, and four to five additional wires are placed in the body. Many other sternal fixation devices are currently available. After placement of the wires, the surgeon must check the undersurface of the bone for bleeding from the mammary vessels, and a hemostatic stitch may be required.

Advantages

This is a simple incision that is easily mastered. It heals quickly, and pain is very well tolerated. This incision provides excellent visualization of the anterior and upper mediastinum. Both pleural spaces can be opened for bilateral procedures in a single setting, although the posterior portions of the chest can be difficult to reach. Median sternotomy can be used for the majority of cardiac procedures. It also can be used to expose the carina from a different angle than thoracotomy. This is achieved by displacing the superior vena cava to the right and the aortic arch to the left and then opening the posterior pericardium. This exposes the right pulmonary artery and the carina.

Disadvantages

Although this incision provides great visualization of the anterior mediastinum and front half of each hemithorax, it is difficult to resect lesions from the posterior lower lobes of the lung through this incision. When embarking on a redo sternotomy, care must be taken to avoid inadvertent entry into the heart, which may be adhered to the underside of the sternum. A lateral radiograph can reveal the degree of adhesion, and preparation for possible emergency cardiopulmonary bypass support can be planned.

Chest Wall Anatomy

The sternum has three component parts: manubrium, body, and xiphoid. The manubrium extends from the sternal notch at the base of the neck to the angle of Louis. The xiphoid is easily palpated. Once the deep fascia is opened over the length of the sternum, the rib insertions into the lateral sternum can be palpated. With a finger pushing into bilateral interspaces at the lateral edge of the body of the sternum, the midpoint of the bone can be marked by electrocautery in the periosteum, facilitating the goal of keeping the saw cut in the midportion of the bone.

Surface Landmarks

Care is taken to place a roll transversely across the most kyphotic portion of the back, and the hips are kept squared so that the chest does not pitch to one side or the other. Subsequently, the surface landmarks are the sternal notch at the base of the neck and the tip of the xiphoid. These two points allow a straight-line incision over the midline of the bone.

General Use

A partial sternotomy generally splits the manubrium and the upper portion of the body of the sternum. It provides access to the thoracic inlet, as well as the upper anterior and upper mid-mediastinal structures. It is particularly useful in approaching the thymus gland and is easily combined with neck incisions to provide proximal and distal control of upper mediastinal arteries and veins.

Technique

The patient is positioned supine with a transverse roll behind the most kyphotic portion of the back. To ensure a vertical midline incision, the hips must be even. A midline incision is made from the angle of Louis inferiorly for about four fingerbreadths. A subcutaneous tunnel is developed superficial to the pectoralis major fascia up to the sternal notch. A transverse venous branch frequently crosses the sternal notch, at the deep level of the manubrium, and should be cauterized. The clavicular– clavicular ligament can be palpated just deep to the undersurface of the manubrium and links the two heads of the clavicles. This is divided with cautery.

This incision can favor the right to displace the right sternal fragment laterally, favor the left to displace the left fragment, or combine with a transverse sternotomy to allow the combined displacement of both fragments (Fig. 2-12). The pectoralis major insertion on the sternum and costal cartilages of the second and third ribs is lifted with electrocautery on the side the incision will favor. A small perforator from the internal mammary vessels can be used to identify the location of the unseen deep artery and both veins. The periosteum of the manubrium is burned in the midline to the angle of Louis. The burn is then extended in a curvilinear manner to the interspace between the second and third or third and fourth ribs. The surgeon's finger passes deep to the manubrium at the sternal notch to bluntly dissect tissue away from the back of the bone. A metal clamp or right angle is used to develop the lateral edge of the bone of the body of the sternum in the rib interspace to insure that the mammary vessels are safely displaced away from the bone. The saw footplate is placed deep to the bone in the sternal notch and pushed or pulled through the center of the manubrium in a careful steady fashion. The saw is gently turned to the rib interspace after the angle of Louis, following the burn in the periosteum. Alternatively, a sternal Lebsche knife can be used to finish the cut into the intercostal space.

Hemostasis is achieved by cauterizing the edges of the periosteum and the application of either bone wax or a topical coagulant, such as Gelfoam soaked in thrombin. A sternal retractor then is placed. The lateral displacement of the fragment is not as much as that occurs with a full sternotomy, but is sufficient to do most dissections in the upper anterior mediastinum.

At the conclusion of the procedure, pleural tubes are placed if the pleurae are open. If the pleurae remain closed, a drainage catheter is frequently not placed since there has been no anticoagulation. The bone fragments are reapproximated with no. 5 surgical steel wires. Most commonly, two simple wires are placed in the manubrium.

Advantages

A partial sternotomy provides nearly the same visualization of the upper anterior mediastinum. Since the angle of Louis corresponds with the carina, any structure in the anterior or middle mediastinal compartment above the level of the carina can be easily approached with this incision. The extension into the neck with a hockey stick incision or a transverse collar incision allows proximal and distal control of the subclavian and carotid arteries, aortic arch, and internal jugular, subclavian, innominate, and brachiocephalic veins. This incision keeps the lower body of the sternum and the costal margins intact. This preserves the respiratory function of the lower ribs for patients with compromised respiratory function. There is less pain and fewer lifting restrictions are required owing to the partial osteotomy. Lifting after partial sternotomy is frequently limited to 20 lbs for 3 weeks, whereas with median sternotomy the lifting restrictions are generally imposed for 8 weeks. Finally, for obese patients, there is less lateral pull to disrupt the partial sternal closure because the lower body of the sternum is intact.

Disadvantage

Since it is only a partial sternotomy, the visualization can be limited at the inferior portion of the osteotomy and laterally at the edges of dissection. If the lateral portion of the osteotomy goes in the interspace between the second and the third rib, the inferior portion of a very large thymus gland may not be seen. If a transverse sternotomy is made, a careful reapproximation of both fragments to the remnant of the body of the sternum must be made. Finally, there is limited visualization into the pleural spaces, and pleural drain placement can be difficult.

Chest Wall Anatomy

The sternum has three component parts: manubrium, body, and xiphoid. The manubrium extends from the sternal notch to the angle of Louis (the cartilage-filled joint between manubrium and upper body of sternum). Once the deep fascia is opened over the planned sternal cut, the rib insertions into the lateral portions of the body of the sternum can be palpated. The rib that inserts into the angle of Louis directly is the second rib.

Surface Landmarks

Care is taken to place a roll transversely across the most kyphotic portion of the back, and the hips are kept squared so that the chest does not pitch to one side or the other. Subsequently, the surface landmarks are the sternal notch at the base of the neck and angle of Louis, where the angle of the manubrium changes from the angle of the body, and the tip of the xiphoid.

General Use

This incision is used primarily to assess lymph node pathology. A small incision at the base of the throat allows access to the mediastinal nodes down to the level of the carina, out to the right pleural reflection, and partly under the aortic arch. It also allows assessment of paratracheal nodes and can be used to assess nodes just inferior to the thyroid gland or beneath the medial sternocleidomastoid muscle.

Technique

The patient is placed supine on the OR table with arms tucked at the side. A transverse roll is placed behind the most kyphotic portion of the back to raise the shoulders and assist in extending the throat as much as possible. A 2-cm transverse incision is made one fingerbreadth above the sternal notch (Fig. 2-13, inset A). Dissection, generally with cautery, is continued in a transverse manner through the platysma muscle, with care taken not to injure the anterior jugular veins. Cautery dissection in a vertical fashion then is alternated with blunt finger dissection. The raphe between the sternothyroid muscles is developed, and the pretracheal fascia is opened. Palpation needs to be made for a high cervical innominate artery, which can appear at the base of the throat. If present, the dissection to the pretracheal fascia will need to be slightly higher and at the level of the isthmus of the thyroid (one cartilaginous ring below the cricoid cartilage). If not present, we prefer to dissect the raphe between the sternothyroid muscles close to the sternal notch to avoid the thyroid gland. Once the pretracheal fascia is opened, the surgeon passes a finger bluntly along the patient's left side of the trachea and into the mediastinum. With the fingernail touching the trachea (Fig. 2-13, inset B), the finger pad should feel the deep cervical fascia give way as one enters into the easier paratracheal plane of the mediastinum. The finger is swept anteriorly between the anterior wall of the trachea and the innominate artery to develop the surgical plane. Palpation is specifically made for lymphadenopathy of the paratracheal gutters and the station 3 lymph node just inferior to the innominate artery. The scope is then inserted for further dissection under direct vision and lymph node biopsy. After satisfactory hemostasis has been obtained, the wound generally is closed in two layers (platysma and skin). Alternatively, a third layer can be placed by reapproximating the strap muscles before closing the platysma.

Advantages

This small incision produces minimal pain and provides invaluable staging information for lung cancer, as well as ready access to the upper middle mediastinum (paratracheal and parabronchial areas). Furthermore, a plane can be developed anterior to the innominate artery and deep to the manubrium to access the anterior upper mediastinum (substernal mediastinoscopy). The greatest advantage is that this central incision offers bilateral access to lymph nodes in the supraclavicular and paratracheal areas, differentiating IIIA (N2 nodes) from IIIB (N₃ nodes) disease in the pathologic staging of lung cancer. The supraclavicular nodes can be accessed by bluntly dissecting laterally beneath the sternocleidomastoid muscle with a finger and then passing the scope onto a firm node, if found.

Disadvantages

Comfort with this incision requires training and experience. Mediastinal vascular structures can be injured, and catastrophic bleeding can occur. Packing the mediastinoscopy wound may be inadequate to control bleeding, and an emergency sternotomy or thoracotomy may be necessary. A sternal saw should be available whenever performing mediastinoscopy.

Chest Wall Anatomy

Cricoid cartilage, sternal notch, heads of the clavicles, sternal heads of the sternocleidomastoid muscles, and the trachea.

Surface Landmarks

The most inferior transverse skin crease of the throat, the sternal notch, the tip of the thyroid cartilage, the anterior curve of the trachea, and the heads of the sternocleidomastoid muscle are used to center the incision.

General Use

This approach is used most commonly to biopsy anterior mediastinal masses that abut the anterior chest wall or biopsy the prevascular (station 6) or aortopulmonary window (station 5) nodes within the left hemithorax. This incision can provide access to all structures medial to the midclavicular lines and anterior to the bronchi, including the internal mammary nodes, the thymus, the pericardium, and the phrenic nerve.

Technique

This incision can be placed in either a right or left parasternal location, within the second to fourth interspace (Fig. 2-14). The most common location is over the top of the third rib in the left parasternal location, which provides access to the aorticopulmonic window nodes. A 2-cm transverse incision is made just to the left of the edge of the sternum (approximately 2 cm lateral to the midpoint of the sternum) and extended over the top of the third rib. Pectoralis major fibers are split along their course, and pectoralis minor fibers generally are more lateral. At the fascia over the external intercostal muscle, a branch of the internal mammary vessels generally can be identified, localizing the hidden vertical course of those vessels. The superficial and deep intercostal muscles are lifted from the top of the third rib down to the level of the intact pleura. The pleura is kept closed and is dissected bluntly from beneath the medial aspect of the incision, separating the pleura from the internal mammary vessels. Blunt dissection is continued beneath the sternum and onto the lateral border of the ascending aorta. At this point, a mediastinoscope is inserted, and dissection is continued with blunt insertion of the scope and a sucker tip to the level of the aorticopulmonic window. Some surgeons prefer a double-lumen endotracheal tube for lung isolation, which may facilitate keeping the pleura closed during the mediastinal dissection. The vacuum within the pleural space pulls the mediastinal pleura laterally during deflation of the ipsilateral lung.

The classic Chamberlain procedure involves a 5- to 6-cm incision over the second costal cartilage, division of the pectoralis major, and resection of the second costal cartilage.⁴ The internal mammary artery is divided. The mediastinum then is entered through the posterior perichondrium. This approach is seldom necessary.

Before closure of the anterior mediastinotomy, an aspiration catheter is placed deep into the intercostal muscles. After the first two layers of closure, a Valsalva maneuver is delivered by the ventilator while aspirating the catheter, which then is removed.

Advantages

This small incision provides well-tolerated access to the mediastinal nodes and anterior mediastinal masses. It can be done under local anesthesia with intravenous sedation in patients unable to tolerate general anesthesia.

Disadvantages

The internal mammary vessels can be injured. If they are completely avulsed, the bleeding ends of these vessels can retract beneath the adjacent ribs. Injury to the hilar vessels or internal mammary vessels can force an emergency enlargement of the incision to an anterolateral thoracotomy. In addition, accurate appreciation of the aorticopulmonic window requires experience. This operation is not mastered easily and requires understanding of subtle changes in the angle of the mediastinoscope. Finally, a disruption to the pleura is possible with lateral extension of the Chamberlain incision. This will produce an ipsilateral pneumothorax. Recognition of such a defect in the pleura should lead to suction within the pleura via a red rubber catheter during a large mechanical ventilator breath before closure of the incision. This maneuver generally is performed after closure of the pectoralis major muscle.

Chest Wall Anatomy

Pectoralis major, pectoralis minor, sternum, costal cartilages, costochondral junctions, internal mammary vessels, ascending aorta, superior vena cava, phrenic nerve, superior pulmonary veins, pulmonary artery, and station 5 and 6 lymph nodes.

Surface Landmarks

Sternal notch, sternomanubrial junction (angle of Louis), edge of the sternum, costal cartilage of the second and third ribs, and head of the clavicle.

General Use

The Eloesser flap was used originally in the treatment of tuberculous empyema.⁵ Since its description in 1935, the Eloesser procedure has been modified.⁶ Dr. Clagett described his simpler technique for treating postpneumonectomy empyema in 1963.⁷ Both techniques are used today in the treatment of chronic empyemas related to parapneumonic effusions and bronchopleural fistulas in frail patients after lung resection. Usually an attempt is made to provide drainage and/or decortication of an infected pleural space with thoracoscopy or thoracotomy as first-line therapy. When these maneuvers fail to completely treat a chronic space infection or the patient is too debilitated to withstand these procedures, open thoracostomy can be used to control the septic process. These chronic openings into the chest allow the wound to granulate and close over time with repeated bedside dressing changes. Alternatively, it may act as a bridge to secondary but definitive wound closure with muscle or omental flaps once the acute infection is under control.

Technique

Under most circumstances, the patient is somewhat debilitated. While the previous thoracotomy incision can be used again, a new incision generally is made in the most dependent location of the chest space to facilitate gravity drainage. Computed tomographic (CT) scan is invaluable in locating the best site for this incision, which can be elliptical (Clagett window; Fig. 2-15, inset A) or U-shaped (Eloesser flap; Fig. 2-15, inset B). Traditionally, between one and three ribs are removed to create a wide, easy-to-pack drainage cavity. In the simpler Clagett window, the edges of the skin then are tacked to the thickened parietal pleura in interrupted fashion to marsupialize the cavity once it has been irrigated and carefully debrided. In an Eloesser flap, the flap created by the U-shaped incision is folded into the chest through the rib defect and sewn to the inside of the ribcage. Both techniques epithelialize the tract and prevent premature closure of the defect. An elliptical incision suffices as much as a U-shaped wound, regardless of its orientation. Hemostasis is confirmed, and the wound is packed with gauze cut to fit as one piece or using multiple rolls tied together, to avoid inadvertent retained packs.

Advantages

This incision allows for targeted drainage with little morbidity in an otherwise debilitated patient population. Dressing care is facilitated with a wide flap, and additional mechanical debridement is established over time with the potential for delayed primary wound closure.

Disadvantages

If the size of the rib resection is not wide or tall enough, the wound at skin level may contract prematurely, before the deeper pocket has granulated. This potentially can allow the infectious process to recur and require repeat surgical drainage. Open thoracostomy creates a permanent chest wall defect. Closure by granulation alone may take months to years. The process generally is accelerated by closure with muscle flaps once the bed of the thorax is clean.

Chest Wall Anatomy

Correlation with CT scanning is important in accessing the infected space at the correct level. Dependent drainage is the key. It is also important to consider future muscle flap options when placing the incision. Depending on previous incisions, the surgeon should make attempts to spare the latissimus or serratus muscle for later use as flaps.

Surface Landmarks

Surface landmarks include the tip of the scapula, the xiphoid process, the costal margin, the anterior border of the latissimus dorsi muscle, and the posterior border of the serratus anterior muscle. Previous incisions should be noted and marked for use as needed during the drainage procedure. Surface landmarks should be correlated with the CT scan images when targeting the fluid collection in question and choosing the approach.

The choice of thoracic incision is the key initial part of every chest operation, but details regarding this choice are often omitted from thoracic surgery textbooks. This chapter was written for the novice. It is unique in its approach to explaining the advantages, disadvantages, uses, and limitations of each incision. It also provides important surface landmarks to use in centering the incision in the correct area. This chapter has been heavily thumbed in the first edition of Adult Chest Surgery kept outside the Brigham Thoracic Surgery operating rooms. It has become an important real-time reference for fellows, residents, students, and nurses.