Advances in general thoracic surgery

Advances in general thoracic surgery

Advances in General Thoracic Surgery Richard H. Feins he last decade has seen tremendous growth in general thoracic surgery. This has been the direct...

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Advances in General Thoracic Surgery Richard H. Feins

he last decade has seen tremendous growth in general thoracic surgery. This has been the direct result of new techniques, new technology, and a new generation of cardiothoracic surgeons specializing in general thoracic surgery- only. Leading the way has been the emergence of video assisted thoracic surgery- (VATS) as an integral part of every general thoracic surgeon's skill set. We have also seen the development of laser bronchoscopy for endobronchial obstructions, video mediastinoscopy, and endoscopic assisted esopbagectomies. In addition, patients with malignancies are being pretreated with chemotherapy and/or radiation therapy, a situation that brings its own set of challenges. This chapter will review some of the major advances in general thoracic surgery with particular reference to its implications for thoracic anesthesia.

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VATS

Tlae use of an endoscope to diagnose and treat pleural disease dates back almost 100 years to when Hans Christian Jacdheus, 1 a urologist, first used a cystoscope to break up adhesions in the pleural space of a patient with tuberculosis. Over the next 30 years, thoracoscopy was widely used for the diagnosis and treatment of tuberculosis. By 1945, however, chemotherapy and advances in surgical techniques had relegated thoracoscopy to a minor role, mostly for diagnostic purposes of pleural disease. That all changed in the late 1980s when the video camera was added to the scope. Before this time, procedures were limited because only the operator looking directly into the scope could see what was happening; the video camera made it possible for several people to assist with procedures. With a number of access ports through the chest wall, surgeons and assistants could retract, cut, sew, and resect thoracic pathology. Two other advances also contributed to the rebirth of thoracoscopy. The first was the ready availability of small fiberoptic bronchoscopes, making easy and exact placement of double-inmen endotracheal tubes possible. 2 Thus, the lung could be readily

deflated on the side of operation and kept that way even with repositioning and operative manipulation. The second advance was the development of an endoscopic stapler capable of entering the chest through a small hole and excising lung tissue while leaving the lung sealed by a staple fine. One of the most common endoscopic procedures performed in our practice is the thoracoscopic wedge resection for diagnosis of the pulmonary nodule. Nodules up to 3 cm in diameter, which are within a few centimeters of the visceral pleural surface, can be wedged out with the endoscopic stapler and removed. This allows for accurate diagnosis and in some cases treatment. There are a few things to consider with this procedure, however. The first is that the surgeon has to be able to find the lesion. When it is 1 cm or greater and on the pleural surface, this is no real problem, but when it is very small and particularly when it is deep in the lung tissue, this can be a real challenge. One technique for finding these lesions is to place a localizing guide wire percutaneously into the lesion preoperatively. The hooked guide wire is left in the patient, and after induction of anesthesia with a double-lumen endotracheal tube and collapse of the appropriate lung, the tissue around the guide wire is removed along with the lesion. The technique requires the anesthesiologist to be on the alert for increased airway pressure mad hemodyuanaic instability on induction from a tension pneumothorax precipitated by positive pressure venfflation of a lung with a small hole in it in which the guide wire was placed. Our technique for finding lesions has been to use a long metal sucker mn along the surface of the lung until the lesion is felt From the Division of Cardiothoracic Surgery, Universay of Rochester Medical Center, Rochester, NY. Address reprint requests ro Richard H. Feins, MD, University of Rochester Medical Center, Division of Cardiothoracic Surgery, 601 Elmwood Avenue, Box SURG, Rochester, NY 14642. E-mail: Richard [email protected] Copyt~ght 2002, Elsevier Science (USA). All rights reserved. 027~0326/02/2103-0000535.0020 doi: l O.1053/sane.2002.00000

Seminars in Anesthesia, Perioperative Medicine and Pain, Vol 21, No 3 (September),2002: pp 241-245

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242 to bump. This technique has been successful in almost 90% of cases and avoids the patient having to have a percutaneous wire placed and the risk of pneumothorax on induction. It is also possible to directly palpate the lung for the lesion with a finger placed through one of the ports. A second major consideration is that tumor cells not be implanted in the port sites when the tumor is extracted from the chest. This requires that all masses be placed in a protective plastic bag before being brought out through the chest wall and i?natinstruments coming in contact with the tumor be placed through thoracoscopy ports. 3 Wedge resection requires as completely an atalectatic lung as possible, and in our practice this is best accomplished with the use of a double-lumen endotracheal tube, which allows for good suction of the collapsed lung. There also can be parenchymal bleeding leading to endohronchial blood, which is best handled with a double-lumen tube. Bronchial blockers of one form or another are used in the rare times when a double-lumen tube cannot be placed. Finally, reexpansion of the lung after wedge resection should be performed in a slow gentle manner so as not to disrupt the staple line. This is particularly true in the very emphysematous lung. Diagnostic VATS for pleural disease is another common procedure. We believe that patients with an tmdiagnosed pleural effusion after thoracentesis should undergo thoracoscopic exploration. At this time, direct biopsy of any pleural-based masses can be performed. If no definite lesions can be observed, multiple biopsies from the parietal pleura will either make the diagnosis or rule out significant pathology in over 90% of cases in our experience. If malignancy is identified and the lung reexpands, a pleuradbesing agent such as sterile talc can be instilled at the same time. One major concern about reexpanding a lung that has been chronically collapsed by a pleural effusion is reexpansion pulmonary edema. Thought to result from too rapid or too vigorous expansion, reexpansion pulmonary edema may render the lung useless and the patient significantly hypoxic and unable to oxygenate. The mortality from reexpansion pulmonary edema is very high.4 Ever since VATS became feasible, many have hoped that it could be used to perform lobectomy and pneumonectomy for the treatment of lung can-

RICHARD H. FEINS cer. Indeed, techniques have been developed to do an anatomic lobectomy and even a mediastinal lymph node dissection. The present technique requires a 3- to 4-cm access thoracotomy incision through which regular thoracotomy instruments can be placed and the specimen removed. It appears that not having to spread the ribs, as is necessary" in the standard thoracotomy, significantly decreases pain in the early postoperative period. VATS lobectomy has been championed by McKeuna 5 and was also found to be feasible in a clinical trial by the Minimally Invasive Thoracic Surgery Group. Plans are now underway to compare VATS Iobectomy with standard thoracotomy in a randomized study (personal communication). There are, however, 2 problems with the VATS lobectomy. The first is that it does take a fair amount of surgical and also endoscopic skill, and it is possible that only a few surgeons will have that skill. Endoscopic procedures that compromise on known surgical principles in the name of minimal invasiveness might well result. An example of this is using a wedge resection as definitive treatment of lung cancer in physically fit patients. Ginsberg6 reporting for the Lung Cancer Study Group showed that local recurrence was significantly increased using a wedge resection as opposed to a formal lobectomy in the open setting and there is no reason to suspect that the same would not be true or even more so in the thoracoscopic setting. Plans are underway, however, for a randomized prospective trial to see if a thoracoscopic wedge is as good as an open lobectomy in the elderly patient. The second problem is that one cannot palpate the lung during an endoscopic procedure, which means that metastatic disease and second primaries may be missed. It is unlikely that preoperative imaging techniques will ever completely solve this problem, although thoracoscopic techniques such as intraoperative ultrasound may help. Bilateral video-assisted thoracic sympathectomy has become the treatment of choice for patients with hyperhydrosis. This procedure has evolved over the last 4 to 5 years from complete removal of a section of the sympathetic chain for 3 to 4 levels to division of the chain at a level specific for the distribution of sweating. Although some centers perform the procedure with a single-lumen endotracheal tube and small delivered tidal volumes by manual ventilation, most use a double-lumen tube

ADVANCES IN GENERAL THORACIC SURGERY and collapse the lung on the operative side. This is our method of choice because we believe having a doubledumen tube gives an added measure of safety should an untoward event occur. The patient is left in the supine position with the arms out on arm boards. Temperature probes are placed on each hand for continuous monitoring during nerve division. One lung is then deflated, and a 5-ram thoracoscope is placed in the chest through a high axillary incision. A second 5-ram port is placed in the anterior axillary line, arid a hook cantery is inserted. The sympathetic chain is readily identified along the posterior rib heads. Correct identification of the second rib (usually the highest one observed) is very important. One must confirm that the rib has intercostal muscle above it to avoid mistaking it for the first rib and inadvertently dividing the stellate ganglion. The temperature in the hand is then noted, and the sympathetic chain is divided at the appropriate levels with the hook cantery set at 20 W. We divide the chain at T2 (along the upper part of the second rib) for facial blushing and sweating and palmar sweating and include division at T3 and T4 (along the 3rd and 4th ribs) for axillary sweating. Care must be taken to stay in the midportion of the rib to avoid intercostal nerve injury. The surface of the 2nd rib should be cleaned laterally to divide the accessory nerve of Kuutz should it be present. A temperature rise of about 2~ is seen almost immediately, although this may vary with the type of sympathetic block achieved with general anesthesia. One must . be very concerned that the T2 level has not been divided if no temperature rise is observed. After the sympathectomy is accomplished, the lung is reinflated with a small suction catheter in the chest, and a similar procedure is performed on the contralateral side. Because for the most part, these patients do not have pulmonary disease, l-lung ventilation in the supine position (rather than in lateral decubitus) can occasionally be a problem as significant shunting may occur. Fortunately, the procedure usually takes less than 10 minutes a side, and we have not found oxygen desaturation a major problem. Severe hradycardia has also been reported after sympathectomy. The most common event for the patient is a sensation of anterior chest pressure in the early postoperative period. This is usually very transient, however.

243 A significant contribution to thoracic surgery is the video mediastinoscope. Before the introduction of video, mediastinoscopy could only be viewed by the operating surgeon. The video mediastinoscope makes it possible for the entire operating room team to see what is happening. This has revolutionized the teaching of the procedure and likely will improve its safety-. In addition, the magnification allowed has improved the ability to get appropriate biopsies. As always, aspiration of any poteutial biopsy site with a fine-gauge needle is essential before biopsy to avoid life-threatening hemorrhage.

MANAGEMENT OF ENDOBRONCHIAL OBSTRUCTION A variety of techniques have emerged for the treatment of endotracheal or endobronchial obstruction. These include coring out tumors, laser bronchoscopy, photodynamic therapy, and intraluminal stenting. For airways obstructed with intraluminal tumor, the YAG (yttrium aluminum garnet) laser can be a very effective way of providing relief. This is particularly true for tumors in the trachea and proximal malnstem bronchi in which normal airway exists distally. For high-grade tracheal obslmction, spontaneous ventilation anesthesia is used until the rigid brnnchoscope is passed and the obstruction bypassed. At this point, the patient can be paralyzed if desired. The patient is ventilated through the adapter on the side of the rigid laser bronchoscope. Before lasering is begun, the inspired oxygen level should be lowered to less than 50% to prevent a possible airway fire. Close commtmication between the operating surgeon and the anesthesiologist is essential because desaturation can occur and is almost always treated by temporarily stopping the laser treatment and increasing the inspired oxygen or by performing adequate airway toilet of the distal airways. Laser treatment of the distal airway may result in desamration and inadequate ventilation if the rigid bmnchoscope is so far down 1 side to preclude adequate ventilation of the contralateral side. The operating surgeon can temporarily withdraw the scope into the proximal airway and restore ventilation to the more normal side. In over 600 laser bronchoscopies since 1987, we have seen significant improvement in about 80% of patients. PoP ypoid lesions are particularly amenable to laser

244 treatment, but care must be taken on induction because positive pressure may result in a ball-valve effect, hyperdistension of the lung, and cardiovascular compromise. In this event, the patient should be awakened and reinduced with spontaneous ventilation until the obsmmtion is alleviated. For patients with obstruction because of external compression, intraluminal stenting with expandable stems can be very effective. These can be placed under general or local anesthesia by using fluoroscopy. We prefer general anesthesia because it gives us better control of the airway and also the option of using the rigid hronchoscope. Stents can be placed for varying distances throughout the proximal airway and even into the segmental oririces, although the latter are prone to obstruction by secretions. By using fluoroscopy and a flexible bronchoscope, the proximal and distal extent of the obstruction is marked on the skirl with paper clips. The compressed steut is then positioned under fluoroscopy to span the lesion and deployed. If the stent is not positioned correctly, it is possible under some conditions to move it with biopsy forceps through the flexible or rigid bronchoscope. Once deployed, one should resist the temptation to place the flexible scope through the stent because this usually tears the rubber covering the distal end of the scope, resulting in a very expensive repair bill. Both laser bronchoscopy and endobronefiial stenting provide inmaediate and fairly durable relief of symptoms. We thus prefer them to photodynamic therapy, which requires multiple endoscopies and an extended time out of bright lights. Newer photoactive agents may alleviate this latter problem.

SURGERY AFTER CHEMOTHERAPYAND RADIATION THERAPY The final area of change for thoracic surgery has been brought about by a significant number of patients being administered neoadjuvant chemotherapy, radiation therapy, or both. This certainly applies to patients with N2 disease (stage IIIA) and, at least in protocol form, patients with less advallced tumors, despite the fact that there are very- little if any phase HI data to support its use. The Intergroup neoadjuvant trial (Int 0139) for patients with N2 disease that compared chemotherapy and radiation therapy followed by surgicai resection to chemotherapy and radiation therapy

RICHARD H. FEINS alone was closed in 2001. Analysis of these data will hopefully show if surgery adds anything to cure rates. Unfortunately, the frustration in dealing with tumors at this stage and a large marketing push from the pharmaceutical industry has made preoperative treatment the standard of care in many places even without any data supporting its efficacy. Operating on patients who have been pretreated with chemotherapy and/or radiation therapy presents major challenges for the surgeon and anesthesiologist. Almost without exception, the surgery can be very difficult. Mediastinal and hilar tissue planes are often eradicated, and identification of vital structures is difficult. The team should be prepared for possible significant blood loss and might even consider venous access from the lower extremities in case injury to the superior vena cava or innominate veins occurs. These procedures can also take much longer than usual and also represent a challenge in fluid management. The second challenge is the prevention of postneoadjuvant acute respiratory distress syndrome. This problem has been summarized nicely in a paper by Fowler et al7 in 1993. Because surgery after neoadjuvant therapy has become more prevalent, the problem of postneoadjuvant ARDS has become much greater, and although many theories exist, there is no consensus as to the causes of the problem, how to prevent it, or how to treat it once it occurs. It does not appear to be dependent on a specific chemotherapeutic agent. Some of the proposed inciting circumstances are high levels of inspired oxygen, large volumes of intraoperative fluid, and barotranma. Because none of these has been proven to be the single culprit, we usually try to limit all 3 during surgery. Some surgeons will pretreat the patient with corticosteroids, although no proof exists that this is beneficial. Fluid restriction, ventilator support, diuretics, and morphine remain the mainstays of treatment. We have seen the condition occur several days after surgery in patients who have had their chemotherapy and/or radiation therapy in the distant past, and it has even occurred in parts of the lung not in the irradiated field. Early recognition and institution of treatment remains very important.

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ADVANCES IN GENERAL THORACIC SURGERY SUMMARY M o d e r n - d ~ y thoracic surgery represents a n e w set o f challenges for the general thoracic surgeon and the anesthesiologist. A i r w a y m a n a g e m e n t , particularly the ability to deliver l - l u n g anesthesia, is critical. T h e use of the v id eo camera has resulted in a m u c h closer w o r k i n g relationship b e t w e e n the general thoracic surgeon and the anesthesiologist. B r o n c h o s c o p y for p l a c e m e n t of the d o u b l e d u m e n endotracheai tube and endobronchial laser therapy, the large variety of video-assisted thoracic surgical procedures, and m o r e recently me di a s t i nos c opy, are all n o w readily visualized by the entire team utilizing video. T h i s has resulted in a m u c h better appreciation for w h a t is g o i n g on in the surgical field and i m p r o v e d care. L u n g resections f o l l o w i n g c h e m o t h e r a p y a n d radiation therapy present an additional set o f challenges. T h e advances d i s c u s s e d in this article are o n l y the b e g i n n i n g as V A T S b e c o m e s even m o r e versatile, robotic instrumentation is developed, and o n c o l o g i c treatment c o m p l i mentary to surgery is advanced. A l l of this places a t r e m e n d o u s burden o n the surgical t e a m and m a k e s g o o d c o m m u n i c a t i o n essential. It is also

essential that the thoracic surgeon take an active role in helping to educate anesthesia residents in the nuances of the procedure f r o m a thoracic surg e o n ' s viewpoint.

REFERENCES 1. Jacobeus H: The cauterization of adhesions in pneumothor~x treatment of mbercuiosis. Surg Gynecol Obstet 32:493 500, 1921 2. Lee AC, Wu CL, Feths RH, et aI: Tile use of fiberoptic endoscopy in anesthesia, in Feins RH (ed). Thoracic Endoscopy. Philadelphia, PA, Saunders, 1996, pp 329-347 3. Downey RJ, McCormack P, Locicero J, et al: Dissemination of malignancies following video-assisted thoracic surgery: A report of twenty cases. J Thorac Cardiovasc Surg 111:954960, 1996 4. Iqbal M, Multz AS, Rossoff LJ, et al: Reexpansion pulmonary edema after VATS successfully treated with continuous positive airway pressure. Ann Thorac Surg 70:669-671, 2000 5. McKenna R/Jr: VATS fubectomy with mediastinal lymph node sampling or dissection. Chest Surg Clin North Am 4:223232, 1995 6. Ginsberg RJ: Resection of non-small cell lung cancer: how much and by what route. Chest 112:203S 205S, I997 7. Fowler WC, Langer CJ, Curran WJ, et al: Postoperative complications after combined neoadjuvant treatment of lung cancer. Ann Tborac Surg 55:986-989, 1993