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Laser-assisted parenchyma-sparing pulmonary resection
J THORAC CARDIOVASC SURa 1989;97:732-6
Laser-assisted parenchyma-sparing pulmonary resection The neodymium:yttrium-aluminum-gamet laser is an excellent tool for removing lesions while sparing surrounding normal tissue. Local excision of 32 pulmonary lesions in 26 patients was performed with the Nd:YAG laser. Fourteen patients had moderate to severe impairment of pulmonary function: average forced vital capacity = 2.2 ± 0.3 L and forced expiratory volume in 1 second = 1.3 ± 0.3 L Limited thoracotomy was used in the last 23 patients. The resected lesions included 16 primary malignant tumors: nine adenocarcinomas, five squamous carcinomas, and two large cell carcinomas. Eight of these lesions were classifiedas Tl NO, sevenwere T2 NO; and one was Tl N2. There were 10 metastatic lesions:three lymphomas, two adenocarcinomas, two leiomyosarcomas,and one case each of melanoma, squamous cell carcinoma, and renal cell carcinoma. There were six benign lesions: three granulomas, two hamartomas, and one carcinoid. Twelve lesions were deep seated, could not have been removed by wedge resection or segmentectomy, and would have necessitated lobectomy without this technique. With the laser, the lesion could be precisely excised with minimal loss of lung parenchyma. Mean operating time was 80 ± 20 minutes; laser resection time was 15 ± 8 minutes. Resection necessitated 10,000 to 20,000 J. Total blood loss was minimal (lessthan 100 00). Chest tubes were always used and remained in place 5 ± 2 days. The mean hospitalization time was 10 ± 2 days. Pulmonary function testing, performed 6 weeks to 6 months after discharge, showed no significant difference from preoperative levels. To date, there have been no local recurrences (longest follow-up 2 years). The Nd:YAG laser is an excellent adjunct for pulmonary resection in patients who have marginal pulmonary function or who have deep parenchymal lesions not amenable to wedge resection. The operative technique for laser resection is presented.
Joseph LoCicero III, MD, James W. Frederiksen, MD, Renee S. Hartz, MD, and Lawrence L. Michaelis, MD, Chicago, Ill.
Er several years, surgeons and pulmonologists have used the neodymium:yttrium-aluminum-garnet laser to extirpate obstructing endobronchial tumors. I. 2 The success of this technique has established it as a standard modality among the many alternative therapies for late stage cancer of the lung. The Nd:YAG laser has all but supplanted the use of the carbon dioxide laser for this purpose because of its ability to seal microscopic vessels and lymphatics deep to the area that is vaporized.' Although the present generation of Nd:YAG lasers is
From the Department of Surgery, Divisionof Cardiothoracic Surgery, Northwestern University Medical School, Chicago, Ill. Read at the Fourteenth Annual Meeting of The Western Thoracic Surgical Association in Hawaii, June 22-25, 1988. Address for reprints: Joseph LoCicero III, MD, Assistant Professor of Surgery, Division of Cardiothoracic Surgery, Northwestern University Medical School, 303 East Chicago Avenue, Ward 9-105, Chicago, IL 60611.
732
easy to handle and requires minimal safety precautions, it has rarely been used for open procedures. The purpose of this report is to define the technique of open laser resection of lung tissue and to show its safety, its efficacy, and its limitations in humans. Methods All clinical studies were performed in accordance with the policies of Northwestern University for experimentation on human beings. Informed consent was obtained from candidates for pulmonary resection. Patients eligible for this procedure were those who had benign pulmonary nodules or malignant disease (either primary or secondary) that did not exceed 6 em in greatest diameter. Initial assessment of eligibility was made on the basis of the preoperative chest roentgenogram and, when available, computed tomography of the chest. Lesions abutting or involving the main pulmonary artery or its major branches near the hilus were not eligiblefor this study. Equipment. The Nd:Y AG laser used for these procedures was a Cooper Laser Sonies (Santa Clara, Calif.) model 8000 Nd:YAG laser with a maximum output of 100 W. The power
Volume 97 Number 5 May 1989
setting used for all resections was 60 W continuous-wave energy. All personnel were required to wear protective glasses specifically for 1060 manometers. All windows into the operating room were shaded and access to the room was limited during use of the laser. The surgeon controlled the energy delivery to the tissue with a foot switch. Standard available operating room suction was used to remove the smoke plume. A thermal printer attached to the laser recorded the number of pulses and the output so that total energy delivery for the procedure could be documented. Technique. All patients underwent exploratory thoracotomy. The anesthetic was delivered through a double-lumen endotracheal tube in most patients. The lesion was located and delivered into the field. At this point, the lung was deflated. The laser was activated and focused with the aiming beam 2 cm from the target. Although other focal lengths are available, this distance worked best for the open procedures. An incision in the visceral pleura was made. For superficial lesions, an encircling incision was used first. For deep-seated lesions, the lung was incised down to the lesion before a circumscribing incision was made. With gentle traction and countertraction between the lesion and the surrounding lung tissue, a plane was developed evenly around the lesion. Suction was always placed in close proximity to the laser to remove the smoke plume. Periodic palpation during the procedure assured complete excision of the tumor and allowed the surgeon to adjust the depth of the laser excision. When the lesion had been removed, a coagulated crater remained. The pleura was reapproximated with absorbable sutures in the initial five patients. In subsequent patients, the crater has been left open and the lung reexpanded. A single chest tube was placed and the thoracotomy incision closed in the usual fashion. The chest tubes were placed on standard chest bottle drainage at 20 cm H 20 suction while the patients' lungs were being ventilated. When the patients were spontaneously breathing and extubated, the suction was discontinued. Each patient was observed every 12 hours for the amount and duration of air leak during the postoperative period. An air leak that was intermittent on or off suction was termed minimal. An air leak present with each breath was considered moderate. A continuous air leak on suction was considered large. The length of time the chest tubes were in place and the hospital stay were recorded. Follow-up. All patients were reexamined 6 weeks and 6 months after discharge from the hospital. When the patient had fully recovered, repeat pulmonary function tests were performed. A posteroanterior roentgenogram of the chest was obtained at each visit.
Results Thirty-two pulmonary lesions have been removed from 26 patients during the past 2Yi years. Five patients had laser excision of a second lesion at the same time and one had a second lesion excised 1 year later. There were 15 women and 11 men with an average age of 56 years. All patients had preoperative pulmonary function tests. The overall average forced vital capacity (FVC) was 2.4 ± 0.3 L with a forced expiratory volume in 1 second (FEV) of 1.7 ± 0.3 L. A subgroup of 14 patients had moderate to severe impairment (FVC = 2.2 ± 0.3 L; FEV! = 1.3 ± 0.3 L). A standard
Laser-assisted pulmonary resection 7 3 3
Table I. Lesions resected with the laser Primary cancers Adenocarcinoma Squamous cell Large cell Metastaticcancers Lymphoma Adenocarcinoma Leiomyosarcoma Squamous cell Melanoma Renal cell Benign lesions Granuloma Hamartoma Carcinoid Total
16
9 5 2 10
3 2 2 I 1 1 6
3 2
1 32
posterolateral thoracotomy was used in the first three patients, but a limited latissimus dorsi-sparing incision is now used. Table I lists the diagnoses encountered in these resected specimens. Sixteen were primary malignant lung tumors: Nine were adenocarcinomas, five were squamous carcinomas, and two were large cell carcinomas. Eight ofthese lesions were classified as T1 NO,and sevenof the carcinomas were T2 NOlesions. One patient had a T1 N2 lesion. None of these patients had metastatic disease. Ten metastatic lesions were encountered. Three patients had lymphoma, and two of them had positive titers for human immunodeficiency virus. Two patients had adenocarcinoma. One patient had two metastatic leiomyosarcoma lesions resected 1 year apart. There was one case each of melanoma, squamous cell carcinoma, and renal cell carcinoma. Six lesions were benign: Three of these were granulomas that had not been evident on earlier roentgenograms of the chest, two were hamartomas, and one was a peripheral carcinoid tumor. Twelve of the lesions described herein were located deep in the lung. Wedge resection or segmentectomy would not have been adequate for complete resection. In these cases, resectioncould have been accomplishedonly with lobectomy. However, with the Nd:YAG laser, lesions could be precisely excised with minimal loss of lung parenchyma. In each case, the remaining lobe functioned well when observed after resection. Mean operating time was 80 ± 20 minutes. Laser resection for each lesion was 15 ± 8 minutes. In those patients who had multiple lesions, the average resection time was 22 minutes. The amount of energy required for resectionvaried according to the consistencyof the lung
734
LoCicero et al.
Fig. 1. Posteroanterior roentgenogramof the chest. A 4 by 5 cm mass is noted in the right upper lung field (arrow).
and the size of the lesion. For the smaller lesions, 10,000 J was required. For the larger lesions, 20,000 J or more was required for resection. With the exception of one patient, all were spontaneously breathing at the conclusion of the operation and all were extubated in the recovery room. The average blood loss for each procedure was less than 100 ml. Air leak in the operating room on positive-pressure ventilation and 22 em H 20 suction was moderate. Air leak in the recovery room in the spontaneously breathing patients without suction was minimal. Chest tubes remained in place an average of 5 ± 2 days. Two patients had a significant pneumothorax without suction, but the pneumothorax resolved with 2 days of suction therapy. The mean postoperative hospitalization study was 8 ± 2 days. Pulmonary function was again tested 6 weeks to 6 months after discharge from the hospital. The FVC was 2.2 ± 0.4 L and the FEV I was 1.5 ± 0.3 L. These results were not significantly different from the preoperative levels. Roentgenograms of the chest obtained at 6-month intervals have demonstrated no local recurrences. The longest follow-up at present is 2 years.
Discussion Surgical resection remains the treatment of choice for primary lung cancer. Although standard resections such as lobectomy and pneumonectomy are performed routinely, a number of series have shown that limited resection can be beneficial, especially in the patient with impaired pulmonary function.': 5 Such interest has prompted the Lung Cancer Study Group to embark on
The Journal of Thoracic and Cardiovascular Surgery
Fig. 2. Posteroanterior roentgenogram of the chest, I month postoperatively, demonstrates the area of resection. The "halo," a common finding after laser resection, is well demonstrated (arrow).
a randomized prospective trial comparing standard lobectomy with limited resection for stage I disease. Recently, Miller and Hatcher" demonstrated a 31% 5-year survival rate among such patients with severe respiratory limitations. Similar parenchyma-sparing operations have been used to aggressively treat pulmonary metastases. Mountain, McMurtrey, and Hermes' described 772 resections in 556 patients who had metastatic disease with an overall 5-year survival rate of 35%.7 One of the contributing advances to improve the morbidity of these limited operations has been the refinement of the surgical stapler. This device has allowed such operations as wedge resection, open lung biopsy, and bleb resection for repeat pneumothorax to proceed rapidly without significant postoperative air or blood leaks from the lung. However, with large or deep-seated lesions, stapling or suturing may distort the remaining lung tissue and thereby jeopardize the vascular supply or inhibit expansion of the remaining normal lung. Even with careful technique, a patient may have a persistent air leak after segmental resection which may prolong the hospital course. Alternatives to suturing or stapling have been suggested in the past. Cooper and co-workers" demonstrated that electrocautery could be used to resect metastatic lesions in the lung with low postoperative morbidity from air leak. However, this procedure is lengthy and requires careful dissection. We 9 suggested the use of the CO 2 laser as an adjunct to minimal
Volume 97 Number 5
Laser-assisted pulmonary resection
May 1989
surgical resection. Early trials with this laser have been suspended because of the necessity to temporarily compress proximal vessels and because of the significant absorption of CO 2 laser energy by diseased human lung tissue, which limits the desired effect. The Nd:YAG laser was suggested as a tool for metastatic pulmonary disease as early as 1967.10 However, inadequate technology limited its use in the operating room. It was only after further refinements that the Nd:YAG laser was again suggested for use in the operating room in 1984.11 Experimental work showed that the acute laser bum on the lung produced coagulated alveoliand thrombosed blood vessels." In comparison to other techniques, the Nd:YAG laser caused more initial damage than either the CO 2 laser or electrocautery." This deep damage (up to 4 mm) may be a theoretical advantage because, in addition to sealing air and blood leaks, it may also destroy small micrometastases present near a lesion. Overtime, the Nd:YAG laser injuries healed well with an organized scar rich in fibroblasts and neovascularization. Although the eventual size of the scar was larger than a suture injury or CO 2 laser injury, it healed faster and with less eventual damage than the electrocautery injury.
Clinically, the Nd:YAG laser is easy to use, necessitating only eye protection for operating room personnel. The laser cuts and coagulates simultaneously so that blood loss is minimal. Lesions can be excised expeditiouslywithout additional techniques to control proximal bloodvessels or airways. Air leaks are minimal and chest tubes have been removed earlier than usual. Minimal or no normal lung tissue is excised with the specimen. Postoperative pulmonary function thus remains essentially the same as in the preoperative state. This makes the laser particularly useful for the older, debilitated patient or the patient wit? marginal pulmonary reserve. During the early postoperative period, chest roentgenograms frequently will show a "halo" at the site of laser excision (Figs. 1 and 2). This area eventually collapses and disappears, a process that may take 6 months to a year. Such a scar may be difficult to evaluate in follow-up of malignant lesions, especially on computed tomographic scan. Theoretically, since the Nd:YAG laser destroys up to 4 mm beyond the cut edge, micrometastasis near the primary lesion should be destroyed and this scar should be of no great concern. The Nd:YAG laser is an excellent adjunct to facilitate limited resections of pulmonary lesions and to minimize perioperative morbidity. Minimal resections can be performed in patients with marginal pulmonary
735
function, and deep parenchymal lesions, previously not amenable to wedge resection, may now be removed while sparing considerable amounts of normally functioning lung. REFERENCES 1. Parr GVS, Unger M, Trout RG, Atkinson WG. One hundred neodymium:YAG laser ablations of obstructing tracheal neoplasms. Ann Thorac Surg 1984;38:374-81. 2. Gelb AF, Epstein JD. Neodyrnium-yttrium-aluminumgarnet laser in lung cancer. Ann Thorac Surg 1987;43: 164-7. 3. Suzuki S, Makino T, Shibata H, et al. A comparative study on application of Nd:YAG laser radiation and electrocautery in canine gastric mucosa: magnified observations by dissecting microscopy, scanning electron microscopy and histologic examinations. Tokai J Exp Clin Med 1982;7:111-26. 4. Shields TW, Higgins GA. Minimal pulmonary resection in treatment of carcinoma of the lung. Arch Surg 1974; 108:420-2. 5. Jensik RJ, Faber LP, Kittle CF. Segmental resection for bronchogenic carcinoma. Ann Thorac Surg 1979;28:47583. 6. Miller JI, Hatcher CR. Limited resection of bronchogenic carcinoma in the patient with marked impairment of pulmonary function. Ann Thorac Surg 1987;44:340-3. 7. Mountain CF, McMurtrey MJ, Hermes KE. Surgery for pulmonary metastasis: a twenty year experience. Ann Thorac Surg 1984;38:323-30. 8. Cooper JD, Perelman MI, Todd TRJ, Ginsberg RJ, Patterson GA, Pearson FG. Precision cautery excision of pulmonary lesions. Ann Thorac Surg 1986;41:51-3. 9. LoCicero J, Hartz RS, Frederiksen JW, Michaelis LL. New applications of the laser in pulmonary surgery: hemostasis and sealing of air leaks. Ann Thorac Surg 1985;40:546-50. 10. Minton JP, Andrews NC, Jesseph JE. Pulsed laser energy in the management of multiple pulmonary metastasis. J THORAC CARDIOVASC SURG 1967;54:707-13. 11. Wolfe WG, Cole PH, Sabiston DC Jr. Experimental and clinical use of the Nd:YAG laser in the management of pulmonary neoplasms. Ann Surg 1984;199:526-31. 12. Cole PH, Wolfe WG. Mechanisms of healing in the injured lung treated with Nd:YAG laser. Lasers Surg Med 1987;6:574-80. 13. LoCicero J, Frederiksen JW, Hartz RS, Michaelis LL. Pulmonary procedures assisted by optosurgical and electrosurgical devices: comparison of damage potential. Lasers Surg Med 1987;7:263-72.
Discussion Dr. Richard M. Peters (San Diego. Calif). I have a number of questions to ask. I think it is good to have another method of limited resection, since I am an advocate of limited resection. When you are through with your specimen, you really have
7 3 6 LoCicero et al.
no way of knowing that you are around the tumor. You just have a char at the edge of the tumor. How have you judged that you are around it, or have you considered the 4 mm char to be your insurance? Dr. LoCicero. You are exactly right. The laser destroys the margin of resection. We feel safe in doing this, because we continually palpate the lesion as we go. Since the lesion itself is much more firm than the char, the surgeon can determine that he is much deeper than the lesion. In general, we go I mm or more beyond the lesion. This, in addition to the 4 mm destruction zone, we believe is adequate. Dr. Peters. I presume that destruction zone goes both into the tumor and away from it. Dr. LoCicero. That is correct. Dr. Peters. You don't try to keep 4 mm away from the tumor, then? Dr. LoCicero. No, we don't. That is a good point, however, and one that is worthwhile considering. Dr. Peters. Some of your patients had NO disease. With this technique, how were you sampling intrapulmonary nodes to be sure that these tumors really were NO? I can understand that you could tell that they weren't N2, but can you really be sure that they were NO? Dr. LoCicero. We did a complete mediastinal dissection to check for N2 nodes. If there were any large nodes in the hilar region by palpation, at least one or more were sampled. Dr. Peters. It is true that you could not take intrapulmonary nodes? Dr. LoCicero. That is correct. Dr. Peters. I think this is an important point to make. When comparing the limited resection to a lobectomy, we must be concerned that the recurrence rate might be higher, not because of incomplete resection of the primary tumor, but because we have no way of assuring that there are NO lesions, as we can when we do a lobectomy. The postoperative halo on the x-ray film doesn't worry me very much. It is just a small cavity in the lung that is
The Journal of Thoracic and Cardiovascular Surgery
collapsing. You expressed concern about the fact that you are going to have difficulty monitoring these patients for recurrence, but the scar doesn't look much larger than it would be for a wedge resection. Is it much more than you would see with a wedge resection? Dr. LoCicero. These postresection halos, even though they collapse, tend to persist for 6 months and to get smaller with time. Although they are a worry, they have not been a major problem for us. Dr. Peters. Dr. LoCicero has presented another method of resection of cancer of the lung that may have an advantage over the use of cautery resection, which I consider to be more effective than wedge resection. Nobody can do a wedge resection, as Dr. LoCicero has suggested, without taking extra lung and without confining the other parts of the lung as the pleural edges are being brought together. With this technique the lung is left open, which-I think is ideal. The question of air leak is important. In terms of air leak, can you give us some idea what the average hospitalization would be for a lobectomy? Is it shorter or longer than for laser resection? Dr. LoCicero. Hospital stay is about a day longer than for the standard lobectomy patient and about the same time as for the segmentectomy patient. However, we have been conservative with this early series. Dr. Peters. Finally, I hope that this new technique won't be another excuse for a higher fee for doing a limited lesion. Surgeons should be paid for their time and skill. If this is an improvement in technique, we should not, as some expect, get paid three times as much because we used a laser. If the laser takes less time and results in a lower prevalence of air leak than with cautery resection, it might be advantageous but probably not worth a fortune in escalating the fee. Dr. LoCicero. In closing, as the years go on, science and technology are going to give us new tools. It is incumbent on us to find the appropriate use for these weapons in the fight against cancer.
Laser-assisted parenchyma-sparing pulmonary resection The neodymium:yttrium-aluminum-gamet laser is an excellent tool for removing lesions while sparing surrounding normal tissue. Local excision of 32 pulmonary lesions in 26 patients was performed with the Nd:YAG laser. Fourteen patients had moderate to severe impairment of pulmonary function: average forced vital capacity = 2.2 ± 0.3 L and forced expiratory volume in 1 second = 1.3 ± 0.3 L Limited thoracotomy was used in the last 23 patients. The resected lesions included 16 primary malignant tumors: nine adenocarcinomas, five squamous carcinomas, and two large cell carcinomas. Eight of these lesions were classifiedas Tl NO, sevenwere T2 NO; and one was Tl N2. There were 10 metastatic lesions:three lymphomas, two adenocarcinomas, two leiomyosarcomas,and one case each of melanoma, squamous cell carcinoma, and renal cell carcinoma. There were six benign lesions: three granulomas, two hamartomas, and one carcinoid. Twelve lesions were deep seated, could not have been removed by wedge resection or segmentectomy, and would have necessitated lobectomy without this technique. With the laser, the lesion could be precisely excised with minimal loss of lung parenchyma. Mean operating time was 80 ± 20 minutes; laser resection time was 15 ± 8 minutes. Resection necessitated 10,000 to 20,000 J. Total blood loss was minimal (lessthan 100 00). Chest tubes were always used and remained in place 5 ± 2 days. The mean hospitalization time was 10 ± 2 days. Pulmonary function testing, performed 6 weeks to 6 months after discharge, showed no significant difference from preoperative levels. To date, there have been no local recurrences (longest follow-up 2 years). The Nd:YAG laser is an excellent adjunct for pulmonary resection in patients who have marginal pulmonary function or who have deep parenchymal lesions not amenable to wedge resection. The operative technique for laser resection is presented.
Joseph LoCicero III, MD, James W. Frederiksen, MD, Renee S. Hartz, MD, and Lawrence L. Michaelis, MD, Chicago, Ill.
Er several years, surgeons and pulmonologists have used the neodymium:yttrium-aluminum-garnet laser to extirpate obstructing endobronchial tumors. I. 2 The success of this technique has established it as a standard modality among the many alternative therapies for late stage cancer of the lung. The Nd:YAG laser has all but supplanted the use of the carbon dioxide laser for this purpose because of its ability to seal microscopic vessels and lymphatics deep to the area that is vaporized.' Although the present generation of Nd:YAG lasers is
From the Department of Surgery, Divisionof Cardiothoracic Surgery, Northwestern University Medical School, Chicago, Ill. Read at the Fourteenth Annual Meeting of The Western Thoracic Surgical Association in Hawaii, June 22-25, 1988. Address for reprints: Joseph LoCicero III, MD, Assistant Professor of Surgery, Division of Cardiothoracic Surgery, Northwestern University Medical School, 303 East Chicago Avenue, Ward 9-105, Chicago, IL 60611.
732
easy to handle and requires minimal safety precautions, it has rarely been used for open procedures. The purpose of this report is to define the technique of open laser resection of lung tissue and to show its safety, its efficacy, and its limitations in humans. Methods All clinical studies were performed in accordance with the policies of Northwestern University for experimentation on human beings. Informed consent was obtained from candidates for pulmonary resection. Patients eligible for this procedure were those who had benign pulmonary nodules or malignant disease (either primary or secondary) that did not exceed 6 em in greatest diameter. Initial assessment of eligibility was made on the basis of the preoperative chest roentgenogram and, when available, computed tomography of the chest. Lesions abutting or involving the main pulmonary artery or its major branches near the hilus were not eligiblefor this study. Equipment. The Nd:Y AG laser used for these procedures was a Cooper Laser Sonies (Santa Clara, Calif.) model 8000 Nd:YAG laser with a maximum output of 100 W. The power
Volume 97 Number 5 May 1989
setting used for all resections was 60 W continuous-wave energy. All personnel were required to wear protective glasses specifically for 1060 manometers. All windows into the operating room were shaded and access to the room was limited during use of the laser. The surgeon controlled the energy delivery to the tissue with a foot switch. Standard available operating room suction was used to remove the smoke plume. A thermal printer attached to the laser recorded the number of pulses and the output so that total energy delivery for the procedure could be documented. Technique. All patients underwent exploratory thoracotomy. The anesthetic was delivered through a double-lumen endotracheal tube in most patients. The lesion was located and delivered into the field. At this point, the lung was deflated. The laser was activated and focused with the aiming beam 2 cm from the target. Although other focal lengths are available, this distance worked best for the open procedures. An incision in the visceral pleura was made. For superficial lesions, an encircling incision was used first. For deep-seated lesions, the lung was incised down to the lesion before a circumscribing incision was made. With gentle traction and countertraction between the lesion and the surrounding lung tissue, a plane was developed evenly around the lesion. Suction was always placed in close proximity to the laser to remove the smoke plume. Periodic palpation during the procedure assured complete excision of the tumor and allowed the surgeon to adjust the depth of the laser excision. When the lesion had been removed, a coagulated crater remained. The pleura was reapproximated with absorbable sutures in the initial five patients. In subsequent patients, the crater has been left open and the lung reexpanded. A single chest tube was placed and the thoracotomy incision closed in the usual fashion. The chest tubes were placed on standard chest bottle drainage at 20 cm H 20 suction while the patients' lungs were being ventilated. When the patients were spontaneously breathing and extubated, the suction was discontinued. Each patient was observed every 12 hours for the amount and duration of air leak during the postoperative period. An air leak that was intermittent on or off suction was termed minimal. An air leak present with each breath was considered moderate. A continuous air leak on suction was considered large. The length of time the chest tubes were in place and the hospital stay were recorded. Follow-up. All patients were reexamined 6 weeks and 6 months after discharge from the hospital. When the patient had fully recovered, repeat pulmonary function tests were performed. A posteroanterior roentgenogram of the chest was obtained at each visit.
Results Thirty-two pulmonary lesions have been removed from 26 patients during the past 2Yi years. Five patients had laser excision of a second lesion at the same time and one had a second lesion excised 1 year later. There were 15 women and 11 men with an average age of 56 years. All patients had preoperative pulmonary function tests. The overall average forced vital capacity (FVC) was 2.4 ± 0.3 L with a forced expiratory volume in 1 second (FEV) of 1.7 ± 0.3 L. A subgroup of 14 patients had moderate to severe impairment (FVC = 2.2 ± 0.3 L; FEV! = 1.3 ± 0.3 L). A standard
Laser-assisted pulmonary resection 7 3 3
Table I. Lesions resected with the laser Primary cancers Adenocarcinoma Squamous cell Large cell Metastaticcancers Lymphoma Adenocarcinoma Leiomyosarcoma Squamous cell Melanoma Renal cell Benign lesions Granuloma Hamartoma Carcinoid Total
16
9 5 2 10
3 2 2 I 1 1 6
3 2
1 32
posterolateral thoracotomy was used in the first three patients, but a limited latissimus dorsi-sparing incision is now used. Table I lists the diagnoses encountered in these resected specimens. Sixteen were primary malignant lung tumors: Nine were adenocarcinomas, five were squamous carcinomas, and two were large cell carcinomas. Eight ofthese lesions were classified as T1 NO,and sevenof the carcinomas were T2 NOlesions. One patient had a T1 N2 lesion. None of these patients had metastatic disease. Ten metastatic lesions were encountered. Three patients had lymphoma, and two of them had positive titers for human immunodeficiency virus. Two patients had adenocarcinoma. One patient had two metastatic leiomyosarcoma lesions resected 1 year apart. There was one case each of melanoma, squamous cell carcinoma, and renal cell carcinoma. Six lesions were benign: Three of these were granulomas that had not been evident on earlier roentgenograms of the chest, two were hamartomas, and one was a peripheral carcinoid tumor. Twelve of the lesions described herein were located deep in the lung. Wedge resection or segmentectomy would not have been adequate for complete resection. In these cases, resectioncould have been accomplishedonly with lobectomy. However, with the Nd:YAG laser, lesions could be precisely excised with minimal loss of lung parenchyma. In each case, the remaining lobe functioned well when observed after resection. Mean operating time was 80 ± 20 minutes. Laser resection for each lesion was 15 ± 8 minutes. In those patients who had multiple lesions, the average resection time was 22 minutes. The amount of energy required for resectionvaried according to the consistencyof the lung
734
LoCicero et al.
Fig. 1. Posteroanterior roentgenogramof the chest. A 4 by 5 cm mass is noted in the right upper lung field (arrow).
and the size of the lesion. For the smaller lesions, 10,000 J was required. For the larger lesions, 20,000 J or more was required for resection. With the exception of one patient, all were spontaneously breathing at the conclusion of the operation and all were extubated in the recovery room. The average blood loss for each procedure was less than 100 ml. Air leak in the operating room on positive-pressure ventilation and 22 em H 20 suction was moderate. Air leak in the recovery room in the spontaneously breathing patients without suction was minimal. Chest tubes remained in place an average of 5 ± 2 days. Two patients had a significant pneumothorax without suction, but the pneumothorax resolved with 2 days of suction therapy. The mean postoperative hospitalization study was 8 ± 2 days. Pulmonary function was again tested 6 weeks to 6 months after discharge from the hospital. The FVC was 2.2 ± 0.4 L and the FEV I was 1.5 ± 0.3 L. These results were not significantly different from the preoperative levels. Roentgenograms of the chest obtained at 6-month intervals have demonstrated no local recurrences. The longest follow-up at present is 2 years.
Discussion Surgical resection remains the treatment of choice for primary lung cancer. Although standard resections such as lobectomy and pneumonectomy are performed routinely, a number of series have shown that limited resection can be beneficial, especially in the patient with impaired pulmonary function.': 5 Such interest has prompted the Lung Cancer Study Group to embark on
The Journal of Thoracic and Cardiovascular Surgery
Fig. 2. Posteroanterior roentgenogram of the chest, I month postoperatively, demonstrates the area of resection. The "halo," a common finding after laser resection, is well demonstrated (arrow).
a randomized prospective trial comparing standard lobectomy with limited resection for stage I disease. Recently, Miller and Hatcher" demonstrated a 31% 5-year survival rate among such patients with severe respiratory limitations. Similar parenchyma-sparing operations have been used to aggressively treat pulmonary metastases. Mountain, McMurtrey, and Hermes' described 772 resections in 556 patients who had metastatic disease with an overall 5-year survival rate of 35%.7 One of the contributing advances to improve the morbidity of these limited operations has been the refinement of the surgical stapler. This device has allowed such operations as wedge resection, open lung biopsy, and bleb resection for repeat pneumothorax to proceed rapidly without significant postoperative air or blood leaks from the lung. However, with large or deep-seated lesions, stapling or suturing may distort the remaining lung tissue and thereby jeopardize the vascular supply or inhibit expansion of the remaining normal lung. Even with careful technique, a patient may have a persistent air leak after segmental resection which may prolong the hospital course. Alternatives to suturing or stapling have been suggested in the past. Cooper and co-workers" demonstrated that electrocautery could be used to resect metastatic lesions in the lung with low postoperative morbidity from air leak. However, this procedure is lengthy and requires careful dissection. We 9 suggested the use of the CO 2 laser as an adjunct to minimal
Volume 97 Number 5
Laser-assisted pulmonary resection
May 1989
surgical resection. Early trials with this laser have been suspended because of the necessity to temporarily compress proximal vessels and because of the significant absorption of CO 2 laser energy by diseased human lung tissue, which limits the desired effect. The Nd:YAG laser was suggested as a tool for metastatic pulmonary disease as early as 1967.10 However, inadequate technology limited its use in the operating room. It was only after further refinements that the Nd:YAG laser was again suggested for use in the operating room in 1984.11 Experimental work showed that the acute laser bum on the lung produced coagulated alveoliand thrombosed blood vessels." In comparison to other techniques, the Nd:YAG laser caused more initial damage than either the CO 2 laser or electrocautery." This deep damage (up to 4 mm) may be a theoretical advantage because, in addition to sealing air and blood leaks, it may also destroy small micrometastases present near a lesion. Overtime, the Nd:YAG laser injuries healed well with an organized scar rich in fibroblasts and neovascularization. Although the eventual size of the scar was larger than a suture injury or CO 2 laser injury, it healed faster and with less eventual damage than the electrocautery injury.
Clinically, the Nd:YAG laser is easy to use, necessitating only eye protection for operating room personnel. The laser cuts and coagulates simultaneously so that blood loss is minimal. Lesions can be excised expeditiouslywithout additional techniques to control proximal bloodvessels or airways. Air leaks are minimal and chest tubes have been removed earlier than usual. Minimal or no normal lung tissue is excised with the specimen. Postoperative pulmonary function thus remains essentially the same as in the preoperative state. This makes the laser particularly useful for the older, debilitated patient or the patient wit? marginal pulmonary reserve. During the early postoperative period, chest roentgenograms frequently will show a "halo" at the site of laser excision (Figs. 1 and 2). This area eventually collapses and disappears, a process that may take 6 months to a year. Such a scar may be difficult to evaluate in follow-up of malignant lesions, especially on computed tomographic scan. Theoretically, since the Nd:YAG laser destroys up to 4 mm beyond the cut edge, micrometastasis near the primary lesion should be destroyed and this scar should be of no great concern. The Nd:YAG laser is an excellent adjunct to facilitate limited resections of pulmonary lesions and to minimize perioperative morbidity. Minimal resections can be performed in patients with marginal pulmonary
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function, and deep parenchymal lesions, previously not amenable to wedge resection, may now be removed while sparing considerable amounts of normally functioning lung. REFERENCES 1. Parr GVS, Unger M, Trout RG, Atkinson WG. One hundred neodymium:YAG laser ablations of obstructing tracheal neoplasms. Ann Thorac Surg 1984;38:374-81. 2. Gelb AF, Epstein JD. Neodyrnium-yttrium-aluminumgarnet laser in lung cancer. Ann Thorac Surg 1987;43: 164-7. 3. Suzuki S, Makino T, Shibata H, et al. A comparative study on application of Nd:YAG laser radiation and electrocautery in canine gastric mucosa: magnified observations by dissecting microscopy, scanning electron microscopy and histologic examinations. Tokai J Exp Clin Med 1982;7:111-26. 4. Shields TW, Higgins GA. Minimal pulmonary resection in treatment of carcinoma of the lung. Arch Surg 1974; 108:420-2. 5. Jensik RJ, Faber LP, Kittle CF. Segmental resection for bronchogenic carcinoma. Ann Thorac Surg 1979;28:47583. 6. Miller JI, Hatcher CR. Limited resection of bronchogenic carcinoma in the patient with marked impairment of pulmonary function. Ann Thorac Surg 1987;44:340-3. 7. Mountain CF, McMurtrey MJ, Hermes KE. Surgery for pulmonary metastasis: a twenty year experience. Ann Thorac Surg 1984;38:323-30. 8. Cooper JD, Perelman MI, Todd TRJ, Ginsberg RJ, Patterson GA, Pearson FG. Precision cautery excision of pulmonary lesions. Ann Thorac Surg 1986;41:51-3. 9. LoCicero J, Hartz RS, Frederiksen JW, Michaelis LL. New applications of the laser in pulmonary surgery: hemostasis and sealing of air leaks. Ann Thorac Surg 1985;40:546-50. 10. Minton JP, Andrews NC, Jesseph JE. Pulsed laser energy in the management of multiple pulmonary metastasis. J THORAC CARDIOVASC SURG 1967;54:707-13. 11. Wolfe WG, Cole PH, Sabiston DC Jr. Experimental and clinical use of the Nd:YAG laser in the management of pulmonary neoplasms. Ann Surg 1984;199:526-31. 12. Cole PH, Wolfe WG. Mechanisms of healing in the injured lung treated with Nd:YAG laser. Lasers Surg Med 1987;6:574-80. 13. LoCicero J, Frederiksen JW, Hartz RS, Michaelis LL. Pulmonary procedures assisted by optosurgical and electrosurgical devices: comparison of damage potential. Lasers Surg Med 1987;7:263-72.
Discussion Dr. Richard M. Peters (San Diego. Calif). I have a number of questions to ask. I think it is good to have another method of limited resection, since I am an advocate of limited resection. When you are through with your specimen, you really have
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no way of knowing that you are around the tumor. You just have a char at the edge of the tumor. How have you judged that you are around it, or have you considered the 4 mm char to be your insurance? Dr. LoCicero. You are exactly right. The laser destroys the margin of resection. We feel safe in doing this, because we continually palpate the lesion as we go. Since the lesion itself is much more firm than the char, the surgeon can determine that he is much deeper than the lesion. In general, we go I mm or more beyond the lesion. This, in addition to the 4 mm destruction zone, we believe is adequate. Dr. Peters. I presume that destruction zone goes both into the tumor and away from it. Dr. LoCicero. That is correct. Dr. Peters. You don't try to keep 4 mm away from the tumor, then? Dr. LoCicero. No, we don't. That is a good point, however, and one that is worthwhile considering. Dr. Peters. Some of your patients had NO disease. With this technique, how were you sampling intrapulmonary nodes to be sure that these tumors really were NO? I can understand that you could tell that they weren't N2, but can you really be sure that they were NO? Dr. LoCicero. We did a complete mediastinal dissection to check for N2 nodes. If there were any large nodes in the hilar region by palpation, at least one or more were sampled. Dr. Peters. It is true that you could not take intrapulmonary nodes? Dr. LoCicero. That is correct. Dr. Peters. I think this is an important point to make. When comparing the limited resection to a lobectomy, we must be concerned that the recurrence rate might be higher, not because of incomplete resection of the primary tumor, but because we have no way of assuring that there are NO lesions, as we can when we do a lobectomy. The postoperative halo on the x-ray film doesn't worry me very much. It is just a small cavity in the lung that is
The Journal of Thoracic and Cardiovascular Surgery
collapsing. You expressed concern about the fact that you are going to have difficulty monitoring these patients for recurrence, but the scar doesn't look much larger than it would be for a wedge resection. Is it much more than you would see with a wedge resection? Dr. LoCicero. These postresection halos, even though they collapse, tend to persist for 6 months and to get smaller with time. Although they are a worry, they have not been a major problem for us. Dr. Peters. Dr. LoCicero has presented another method of resection of cancer of the lung that may have an advantage over the use of cautery resection, which I consider to be more effective than wedge resection. Nobody can do a wedge resection, as Dr. LoCicero has suggested, without taking extra lung and without confining the other parts of the lung as the pleural edges are being brought together. With this technique the lung is left open, which-I think is ideal. The question of air leak is important. In terms of air leak, can you give us some idea what the average hospitalization would be for a lobectomy? Is it shorter or longer than for laser resection? Dr. LoCicero. Hospital stay is about a day longer than for the standard lobectomy patient and about the same time as for the segmentectomy patient. However, we have been conservative with this early series. Dr. Peters. Finally, I hope that this new technique won't be another excuse for a higher fee for doing a limited lesion. Surgeons should be paid for their time and skill. If this is an improvement in technique, we should not, as some expect, get paid three times as much because we used a laser. If the laser takes less time and results in a lower prevalence of air leak than with cautery resection, it might be advantageous but probably not worth a fortune in escalating the fee. Dr. LoCicero. In closing, as the years go on, science and technology are going to give us new tools. It is incumbent on us to find the appropriate use for these weapons in the fight against cancer.