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Thoracoscopic thymectomy in juvenile myasthenia gravis
Thoracoscopic Thymectomy in Juvenile Myasthenia Gravis By Hanna Kolski, Jiri Vajsar, and Peter C.W. Kim Toronto, Ontario
Background: Although transsternal thymectomy is an effective method in the treatment of juvenil myasthenia gravis (JMG) it is traumatic in pediatric patients. Thoracoscopic thymectomy offers an effective and less traumatic approach with respect to cosmesis and postoperative recovery. Methods: A retrospective analysis of 6 consecutive patients treated with thoracoscopic thymectomy was performed. Perioperative parameters and cost analysis were compared with those of 6 consecutive open procedures performed before the study. Results: Thoracoscopic thymectomy can be performed in patients as young as 1.6 years. There was no conversion to open procedure and no perioperative morbidity and mortality. The length of operating time and the surgical cost of thoracoscopic procedure were not significantly different from
M
YASTHENIA GRAVIS (MG) is an uncommon autoimmune condition causing progressive weakness of the neuromuscular system, and the role of thymectomy in treatment scheme is well established.1-3 The goal of thymectomy in the treatment of MG is to achieve complete resection of the thymus. Hence, median sternotomy traditionally has been the gold standard favored by surgeons.3-5 The transcervical approach has been reported to achieve a complete resection with better cosmesis and shorter recovery period than median sternotomy.4 More recently, the use of thoracoscopic technique in the treatment of MG has been reported to achieve equivalent surgical outcomes compared with transsternal approach with shorter postoperative analgesic requirement and shorter length of hospitalization.6-8 There are very few reports in the adult literature on the efficacy of thoracoscopic thymectomy in the treat-
From the Departments of Neurology and Surgery, University of Toronto, Hospital for Sick Children, Toronto, Ontario, Canada. Presented at the 31st Annual Meeting of the Canadian Association of Paediatric Surgeons, Montreal, Quebec, Canada, September 23-26, 1999. Address reprint requests to Peter C.W. Kim, The Hospital for Sick Children, 555 University Ave, Rm 1526, Toronto, Ontario, Canada M5G 1X8. Copyright r 2000 by W.B. Saunders Company 0022-3468/00/3505-0030$03.00/0 doi:10.1053/js.2000.6065
768
those of open procedure. The length of hospitalization, however, was significantly shorter with thoracoscopic procedure, and hence the overall cost was significantly reduced (P , .05). An intermediate follow-up shows that outcome after thoracoscopic procedure is equally as effective as open procedure.
Conclusions: Thoracoscopic thymectomy offers an equally effective but cosmetically more acceptable approach than sternotomy. It has a quicker recovery period and appears to be a less costly alternative to transsternal thymectomy. J Pediatr Surg 35:768-770. Copyright r 2000 by W.B. Saunders Company. INDEX WORDS: Juvenile myasthenia gravis, thoracoscopic thymectomy.
ment of MG.8,9 The role of thoracoscopic thymectomy in children, however, remains to be established.8,9 In this retrospective analysis, we report the results of 6 consecutive patients with juvenile MG (JMG) treated with thoracoscopic thymectomy.
MATERIALS AND METHODS Six consecutive patients at the Hospital for Sick Children who required total thymectomy for generalized juvenile MG between 1996 and 1998 were analyzed for patient demographics and perioperative parameters, including surgical cost, length of hospitalization, and length of intravenous analgesic requirement. These data were compared with those of 6 consecutive patients who had undergone transsternal thymectomy. The indication for operation was generalized or bulbar weakness not responding to optimal medical treatment. In the thoracoscopic thymectomy group there were 2 patients in Osserman stage IIA (mild generalized), 1 with IIB (moderate generalized), and 3 patients with stage III (acute fulminating).10 The Student’s t test was used for statistical analysis (P , .05).
RESULTS
Thoracoscopic Thymectomy After general anesthesia, patients were placed in a supine position with a sandbag under the right scapula achieving 15° elevation of the right chest cavity. The right axilla was exposed with the arm in an extended position (Fig 1A). In one of the patients (1.6 year old), Journal of Pediatric Surgery, Vol 35, No 5 (May), 2000: pp 768-770
THORACOSCOPIC THYMECTOMY IN MYASTHENIA GRAVIS
769
significantly different from the mean of 142 6 41 minutes for the open procedure. Similarly, the mean postoperative intravenous analgesic requirement of 0.8 days in the thoracoscopic group was not significantly different from the mean of 1.4 days required by the patients in the open thymectomy group. The average cost per surgical procedure for thoracoscopic procedure was $3,377.91 Canadian dollars (CAD). The average cost per open procedure without nursing or anaesthesia costs indexed for 1999 was $3,821.02 CAD. Because thoracoscopic procedure significantly reduced the average length of hospital stay from 6.8 6 1.3 days for open procedure to 3 6 0.5 days for thoracoscopic procedure, the resulting overall cost of the surgical treatment using thoracoscopic technique also was significantly reduced from $9,805.02 CAD to $6,017.91 CAD (P , .05). An average follow-up of 22 months showed that all patients are improved significantly, and half of the patients are off medications. DISCUSSION
`
Fig 1. A schematic representation of lateral (A) and anterior (B) views of thoracoscopic port placement. The right chest cavity was elevated by 15° with a support. n represents a 10-mm camera port; s represents operating ports; and represents an additional 5-mm port used for traction.
one lung ventilation was achieved by selective left lung intubation. The use of a bronchial blocker in the right main stem bronchus was used for the rest of patients. Three thoracoscopic ports were placed in an inverted triangle position in the right axilla with a 10-mm, 30° angled camera port at the posterior axillary line in the fourth intercostal space, and 2 5-mm operating ports at the anterior axillary line in the third and fifth intercostal spaces (Fig 1A). In some of the surgeries, a fourth 5-mm port was placed in the seventh intercostal space at the midclavicular line to provide additional traction for the dissection of superior poles (Fig 1B). There was no conversion to open technique, no complication, no postoperative ventilation, and no mortality. Perioperative Parameters Patient age, Osserman stage, mean operating time, length of hospital stay, and average cost are shown in Table 1. The mean age of the patients and the preoperative Osserman stages were compatible to those reported previously.3 The mean operating time of the thoracoscopic procedures was compared with that of 6 consecutive transsternal thymectomies performed between 1987 and 1995. The mean operating time of 199 6 15 minutes for the thoracoscopic procedure was not statistically
In this study, we report the results of 6 consecutive thoracoscopic thymectomies performed for JMG. The rigidity of the chest cavity often limits the accessibility of any intervention without making a large incision. Thoracoscopic procedures are ideally suited for partial or complete removal of lesions in the chest cavity. This is particularly true in the case of MG in which thymus often is normal or only mildly enlarged in size. The concern about the completeness of resection and surgical exposure unless a median sternotomy is performed is not evidence based.3,5,8,9 Although long-term follow-up is needed, our intermediate follow-up of these patients shows that the surgical outcomes of thoracoscopic thymectomy are at least equivalent to the open technique and support the view that the above concerns are not justified. Thoracoscopic thymectomy for MG in children appears to offer as complete a surgical resection as open transsternal techniques. This procedure results in a shorter hospital stay, quicker recovery, better cosmesis, and significantly reduces the overall cost to health care.
Table 1. Perioperative Parameters for Thoracoscopic Thymectomy Patients Patients 1
Age (yr) Osserman stages Length of surgery (min) Intravenous morphine (d) Length of hospitalization (d)
1.6 III 170
2
10.6 III
3
11.7 IIA
4
5
10 IIB
14.6 IIA 215
6
14.4 III
215
164
230
200
0.25
0
1
1
0.25
2.5
4.5
2.5
3.5
2.5
3.5
3.5
770
KOLSKI, VAJSAR, AND KIM
REFERENCES 1. Seybold ME: Thymectomy in childhood myasthenia gravis. Ann N Y Acad Sci 841:731-741, 1998 2. Andrews PI: A treatment for autoimmune myasthenia gravis in childhood. Ann N Y Sci 841:788-802, 1998 3. Adams C, Theodorescu D, Murphy EG, et al: Thymectomy in juvenile myasthenia gravis. J Child Neurol 5:215-218, 1990 4. Cooper JD, Al-Jilaihawa AN, Pearson FG, et al: An improved technique to facilitate Transcervical Thymectomy for Myasthenia Gravis. Ann Thorac Surg 45:242-247, 1988 5. Yousef S: Thymectomy for myasthenia gravis in children. J Pediatr Surg 18:537-541, 1983 6. Mack MJ, Landreneau RJ, Yim AP, et al: Results of video-assisted
thymectomy in patients with myasthenia gravis. J Thorac Cardiovasc Surg 112:1352-1360, 1996 7. Mack MJ, Scruggs GR: Video-assisted thymectomy for myasthenia gravis. Chest Surg Clin North Am 8:809-825, 1998 8. Mantegazza R, Confalonieri P, Antozzi C, et al: Video-assisted thoracoscopic extended thymectomy in myasthenia gravis. Two-year follow-up in 101 patients and comparison with the transsternal approach. Ann N Y Acad Sci 11:65-73, 1999 9. Yim AP, Low JM, Ng K, et al: Video-assisted thocoscopic surgery in the pediatric population. J Pediatr Child Health 31:192-196, 1995 10. Osserman KE, Genkins G: Studies in myasthenia gravis: Review of a twenty-year experience in over 1200 patients. The Mount Sinai Journal of Medicine. 38:497, 1971
Background: Although transsternal thymectomy is an effective method in the treatment of juvenil myasthenia gravis (JMG) it is traumatic in pediatric patients. Thoracoscopic thymectomy offers an effective and less traumatic approach with respect to cosmesis and postoperative recovery. Methods: A retrospective analysis of 6 consecutive patients treated with thoracoscopic thymectomy was performed. Perioperative parameters and cost analysis were compared with those of 6 consecutive open procedures performed before the study. Results: Thoracoscopic thymectomy can be performed in patients as young as 1.6 years. There was no conversion to open procedure and no perioperative morbidity and mortality. The length of operating time and the surgical cost of thoracoscopic procedure were not significantly different from
M
YASTHENIA GRAVIS (MG) is an uncommon autoimmune condition causing progressive weakness of the neuromuscular system, and the role of thymectomy in treatment scheme is well established.1-3 The goal of thymectomy in the treatment of MG is to achieve complete resection of the thymus. Hence, median sternotomy traditionally has been the gold standard favored by surgeons.3-5 The transcervical approach has been reported to achieve a complete resection with better cosmesis and shorter recovery period than median sternotomy.4 More recently, the use of thoracoscopic technique in the treatment of MG has been reported to achieve equivalent surgical outcomes compared with transsternal approach with shorter postoperative analgesic requirement and shorter length of hospitalization.6-8 There are very few reports in the adult literature on the efficacy of thoracoscopic thymectomy in the treat-
From the Departments of Neurology and Surgery, University of Toronto, Hospital for Sick Children, Toronto, Ontario, Canada. Presented at the 31st Annual Meeting of the Canadian Association of Paediatric Surgeons, Montreal, Quebec, Canada, September 23-26, 1999. Address reprint requests to Peter C.W. Kim, The Hospital for Sick Children, 555 University Ave, Rm 1526, Toronto, Ontario, Canada M5G 1X8. Copyright r 2000 by W.B. Saunders Company 0022-3468/00/3505-0030$03.00/0 doi:10.1053/js.2000.6065
768
those of open procedure. The length of hospitalization, however, was significantly shorter with thoracoscopic procedure, and hence the overall cost was significantly reduced (P , .05). An intermediate follow-up shows that outcome after thoracoscopic procedure is equally as effective as open procedure.
Conclusions: Thoracoscopic thymectomy offers an equally effective but cosmetically more acceptable approach than sternotomy. It has a quicker recovery period and appears to be a less costly alternative to transsternal thymectomy. J Pediatr Surg 35:768-770. Copyright r 2000 by W.B. Saunders Company. INDEX WORDS: Juvenile myasthenia gravis, thoracoscopic thymectomy.
ment of MG.8,9 The role of thoracoscopic thymectomy in children, however, remains to be established.8,9 In this retrospective analysis, we report the results of 6 consecutive patients with juvenile MG (JMG) treated with thoracoscopic thymectomy.
MATERIALS AND METHODS Six consecutive patients at the Hospital for Sick Children who required total thymectomy for generalized juvenile MG between 1996 and 1998 were analyzed for patient demographics and perioperative parameters, including surgical cost, length of hospitalization, and length of intravenous analgesic requirement. These data were compared with those of 6 consecutive patients who had undergone transsternal thymectomy. The indication for operation was generalized or bulbar weakness not responding to optimal medical treatment. In the thoracoscopic thymectomy group there were 2 patients in Osserman stage IIA (mild generalized), 1 with IIB (moderate generalized), and 3 patients with stage III (acute fulminating).10 The Student’s t test was used for statistical analysis (P , .05).
RESULTS
Thoracoscopic Thymectomy After general anesthesia, patients were placed in a supine position with a sandbag under the right scapula achieving 15° elevation of the right chest cavity. The right axilla was exposed with the arm in an extended position (Fig 1A). In one of the patients (1.6 year old), Journal of Pediatric Surgery, Vol 35, No 5 (May), 2000: pp 768-770
THORACOSCOPIC THYMECTOMY IN MYASTHENIA GRAVIS
769
significantly different from the mean of 142 6 41 minutes for the open procedure. Similarly, the mean postoperative intravenous analgesic requirement of 0.8 days in the thoracoscopic group was not significantly different from the mean of 1.4 days required by the patients in the open thymectomy group. The average cost per surgical procedure for thoracoscopic procedure was $3,377.91 Canadian dollars (CAD). The average cost per open procedure without nursing or anaesthesia costs indexed for 1999 was $3,821.02 CAD. Because thoracoscopic procedure significantly reduced the average length of hospital stay from 6.8 6 1.3 days for open procedure to 3 6 0.5 days for thoracoscopic procedure, the resulting overall cost of the surgical treatment using thoracoscopic technique also was significantly reduced from $9,805.02 CAD to $6,017.91 CAD (P , .05). An average follow-up of 22 months showed that all patients are improved significantly, and half of the patients are off medications. DISCUSSION
`
Fig 1. A schematic representation of lateral (A) and anterior (B) views of thoracoscopic port placement. The right chest cavity was elevated by 15° with a support. n represents a 10-mm camera port; s represents operating ports; and represents an additional 5-mm port used for traction.
one lung ventilation was achieved by selective left lung intubation. The use of a bronchial blocker in the right main stem bronchus was used for the rest of patients. Three thoracoscopic ports were placed in an inverted triangle position in the right axilla with a 10-mm, 30° angled camera port at the posterior axillary line in the fourth intercostal space, and 2 5-mm operating ports at the anterior axillary line in the third and fifth intercostal spaces (Fig 1A). In some of the surgeries, a fourth 5-mm port was placed in the seventh intercostal space at the midclavicular line to provide additional traction for the dissection of superior poles (Fig 1B). There was no conversion to open technique, no complication, no postoperative ventilation, and no mortality. Perioperative Parameters Patient age, Osserman stage, mean operating time, length of hospital stay, and average cost are shown in Table 1. The mean age of the patients and the preoperative Osserman stages were compatible to those reported previously.3 The mean operating time of the thoracoscopic procedures was compared with that of 6 consecutive transsternal thymectomies performed between 1987 and 1995. The mean operating time of 199 6 15 minutes for the thoracoscopic procedure was not statistically
In this study, we report the results of 6 consecutive thoracoscopic thymectomies performed for JMG. The rigidity of the chest cavity often limits the accessibility of any intervention without making a large incision. Thoracoscopic procedures are ideally suited for partial or complete removal of lesions in the chest cavity. This is particularly true in the case of MG in which thymus often is normal or only mildly enlarged in size. The concern about the completeness of resection and surgical exposure unless a median sternotomy is performed is not evidence based.3,5,8,9 Although long-term follow-up is needed, our intermediate follow-up of these patients shows that the surgical outcomes of thoracoscopic thymectomy are at least equivalent to the open technique and support the view that the above concerns are not justified. Thoracoscopic thymectomy for MG in children appears to offer as complete a surgical resection as open transsternal techniques. This procedure results in a shorter hospital stay, quicker recovery, better cosmesis, and significantly reduces the overall cost to health care.
Table 1. Perioperative Parameters for Thoracoscopic Thymectomy Patients Patients 1
Age (yr) Osserman stages Length of surgery (min) Intravenous morphine (d) Length of hospitalization (d)
1.6 III 170
2
10.6 III
3
11.7 IIA
4
5
10 IIB
14.6 IIA 215
6
14.4 III
215
164
230
200
0.25
0
1
1
0.25
2.5
4.5
2.5
3.5
2.5
3.5
3.5
770
KOLSKI, VAJSAR, AND KIM
REFERENCES 1. Seybold ME: Thymectomy in childhood myasthenia gravis. Ann N Y Acad Sci 841:731-741, 1998 2. Andrews PI: A treatment for autoimmune myasthenia gravis in childhood. Ann N Y Sci 841:788-802, 1998 3. Adams C, Theodorescu D, Murphy EG, et al: Thymectomy in juvenile myasthenia gravis. J Child Neurol 5:215-218, 1990 4. Cooper JD, Al-Jilaihawa AN, Pearson FG, et al: An improved technique to facilitate Transcervical Thymectomy for Myasthenia Gravis. Ann Thorac Surg 45:242-247, 1988 5. Yousef S: Thymectomy for myasthenia gravis in children. J Pediatr Surg 18:537-541, 1983 6. Mack MJ, Landreneau RJ, Yim AP, et al: Results of video-assisted
thymectomy in patients with myasthenia gravis. J Thorac Cardiovasc Surg 112:1352-1360, 1996 7. Mack MJ, Scruggs GR: Video-assisted thymectomy for myasthenia gravis. Chest Surg Clin North Am 8:809-825, 1998 8. Mantegazza R, Confalonieri P, Antozzi C, et al: Video-assisted thoracoscopic extended thymectomy in myasthenia gravis. Two-year follow-up in 101 patients and comparison with the transsternal approach. Ann N Y Acad Sci 11:65-73, 1999 9. Yim AP, Low JM, Ng K, et al: Video-assisted thocoscopic surgery in the pediatric population. J Pediatr Child Health 31:192-196, 1995 10. Osserman KE, Genkins G: Studies in myasthenia gravis: Review of a twenty-year experience in over 1200 patients. The Mount Sinai Journal of Medicine. 38:497, 1971