Pulmonary function after thoracoscopic thymectomy versus median sternotomy for myasthenia gravis

BACKGROUND: Impaired pulmonary function due to myasthenia gravis (MG) is further compromised by thymectomy, which is necessary in most cases. Thoracoscopic thymectomy (tThx) can achieve the same resection and functional improvement of MG as median sternotomy (sThx). The possible advantage of tThx in maintaining better perioperative lung function was quantified. METHODS: In a prospective trial, 20 patients with MG were randomly allocated to undergo tThx (n = 10) by three-trocar left-sided approach or sThx (n = 10) performed as an extended procedure. Complete pulmonary function was measured at 12-hour intervals, beginning 6 hours postoperatively. Effective postoperative pain control in both groups was achieved by patient-controlled analgesia with morphine sulfate assessed by a visual analogue scale. Statistical analysis for comparison of tThx and sThx was performed using the Mann-Whitney U test. RESULTS: Postoperative vital capacity, forced vital capacity, forced expiratory volume per second, and peak expiratory flow, measured as a percentage of the individual preoperative capacity, were significantly better with tThx compared with sThx. Immediate postoperative lung function was reduced to 35% and 65% after tThx and sThx, respectively. By the third postoperative day, recovery of pulmonary function was complete after tThx but only 55% after sThx. CONCLUSIONS: Less pronounced impairment and faster recovery of pulmonary function after tThx characterize this new approach for thymectomy as minimally invasive. These results could make tThx the preferred surgical treatment of MG, which was improved to the same extent as after sThx.     

横断胸骨扩大胸腺切除治疗全身型重症肌无力

目的探讨经横断胸骨入路行扩大胸腺切除治疗重症肌无力的临床疗效。了解该入路的特点及临床疗效有助于该领域胸外科医师在临床实践中进行更好的临床决策。 方法对1998至2008年在复旦大学附属华山医院胸心外科行横断胸骨治疗全身型重症肌无力的211例患者的临床资料进行回顾性研究,分析患者术中和术后基本情况。并对术后5年进行随访的患者根据是否合并胸腺瘤进行分组,采用χ²检验比较两组间的疗效。 结果经横断胸骨入路能满足对合并Masaoka-Koga Ⅰ期及Ⅱ期胸腺瘤患者及无瘤患者实施扩大胸腺切除的需要,手术并发症较低,便于围术期护理,恢复迅速。对173例患者进行术后5年随访,总缓解率达到79.8%(138/173),无肿瘤复发。合并胸腺瘤组的总缓解率为81.9%(59/72),未合并胸腺瘤组的总缓解率为78.2%(79/101),两组间比较差异无统计学意义(χ²＝0.362,P＝0.548)。 结论与其他常用手术入路相比,横断胸骨入路的特点值得该领域胸外科医师关注。     

Transcervical thymectomy for myasthenia gravis achieves results comparable to thymectomy by sternotomy

BACKGROUND: It remains controversial whether transcervical thymectomy offers results equivalent to thymectomy by way of a median sternotomy in the treatment of myasthenia gravis. Furthermore, preoperative prognostic factors have not been clearly defined. METHODS: This study is a retrospective chart review and interview of 78 patients completing transcervical thymectomy for myasthenia gravis between 1992 and 1999. RESULTS: There were 24 men and 54 women. Mean age was 40 years (range, 13 to 78 years). Twelve patients were in Osserman class 1, 25 in class 2, 30 in class 3, and 11 in class 4 (mean, 2.5). There was no perioperative mortality and 6 (7.7%) morbidities. Mean length of stay was 1.5 days and mean follow-up, 54.6 months. The crude cumulative complete remission (asymptomatic off medications for 6 months) rate was 39.7% (n = 31). Only 8 patients (10.3%) failed to improve after transcervical thymectomy. Kaplan-Meier estimates of complete remission were 31% and 43% at 2 and 5 years, respectively. Eight patients with thymoma had a 5-year estimated complete remission rate of 75% in contrast to 43% in 38 patients with thymic hyperplasia and 36% in 32 patients with neither thymoma nor hyperplasia (p = 0.01). Twelve patients with ocular myasthenia had a 5-year estimated complete remission rate of 57%, whereas patients with mild-to-moderate (n = 55) or severe (n = 11) generalized symptoms had 5-year complete remission rates of 43% and 30%, respectively (p = 0.21). CONCLUSIONS: Overall, extended transcervical thymectomy offers results that are comparable to those published for the transsternal procedure. Patients with milder disease (including isolated ocular disease) and taking no preoperative immunosuppressive agents appear to experience higher remission rates. In contrast to previous studies, we also find that small thymomas predict better responses to thymectomy.     

胸骨部分劈开切口行扩大的胸腺切除术治疗重症肌无力

目的介绍胸骨部分劈开切口行扩大的胸腺切除术治疗重症肌无力的手术方法和效果。方法2000年1月至2005年12月,采用胸骨正中部分劈开切口,对32例重症肌无力患者进行了扩大的胸腺切除手术。结果6例肌无力症状完全缓解,19例症状显著改善,5例症状轻微改善,而仅有2例手术后症状完全没有好转。结论胸骨部分劈开切口是实施扩大的胸腺切除治疗重症肌无力的一种安全、有效的手术径路,并且对患者的创伤小,避免了手术后并发症,特别是肌无力危象的发生。     

Role of video-assisted thoracic surgery for the treatment of myasthenia gravis: extended thymectomy by median sternotomy versus the thoracoscopic approach with sternal lifting

The role of video-assisted thoracic surgery (VATS) thymectomy is still being studied, and many surgeons remain skeptical of the value of this recent option. We made a retrospective evaluation to ascertain whether VATS-extended thymectomy is as reliable as standard median sternotomy in the treatment of myasthenia gravis (MG) and whether the endoscopic procedure presents any advantages for patients. Eighteen consecutive patients requiring extended thymectomy for MG were treated between April 1997 and September 2003 at our hospital. Nine patients received VATS-extended thymectomy, and the remaining nine patients received standard extended thymectomy by sternotomy. In the VATS group, the anterior mediastinal space was well visualized by sternal lifting. The mean operative time was 268.3 +/- 51.1 minutes in the VATS group and 177.3 +/- 92.5 minutes in the sternotomy group. Operative time was significant longer in the VATS group than in the sternotomy group (P < 0.05). The mean operative bleeding was 68.6 +/- 47.8 ml in the VATS group and 154.1 +/- 109.0 ml in the sternotomy group. Operative bleeding was significantly less in the VATS group than in the sternotomy group (P < 0.05). There was no significant difference between the two groups with regard to postoperative duration of chest tube or the level of serum C-reactive protein on the first operative day. There was a downward trend in nicotinic acetylcholine receptors antibody levels after thymectomy compared with before thymectomy in both groups. VATS thymectomy should be considered a valid alternative to the established approaches aimed at achieving a "curative thymectomy" in patients with MG.     

Transcervical thymectomy for myasthenia gravis.

The authors of this article contend that the transcervical approach for thymectomy allows the safe and complete removal of the thymus and [table: see text] provides equivalent benefit to the patients with regard to opportunity for clinical remission or freedom from progression of the symptoms of MG. The low morbidity and short hospitalization after transcervical thymectomy represent minimal barriers and allow increased willingness of the neurologist to refer a patient for surgical therapy and increased acceptance of the patient towards the recommendations. The authors believe that an early, safe, and complete thymectomy offers all the benefits of surgical removal of the thymus to a patient with MG with minimal risk for morbidity and postoperative pain.     

重症肌无力电视胸腔镜与胸骨部分劈开行胸腺扩大切除比较

目的 探讨电视胸腔镜手术(VATS)在重症肌无力(MG)治疗中的价值.方法 应用随机对照研究前瞻性分析2005年至2008年开展的VATS和胸骨部分劈开行胸腺切除治疗MG疗效,比较两组在手术时间、术中出血量、术后胸管放置时间、术后住院时间、术后发生重症肌无力危象及疗效等方面差异.结果 VATS组中26例手术顺利,1例因电凝钩伤及头臂静脉中转开胸.与部分胸骨劈开组比较,VATS组术中出血少、手术时间短、术后放置胸管时间及术后住院时间缩短.VATS组与胸骨劈开组比较发生肌无力危象0例对3例,肺部感染2例对9例,胸骨上窝或伤口感染0例对3例.随访6～24个月,VATS和胸骨劈开组有效率分别为81%(21/26例)和85%(23/27例),差异无统计学意义.结论 VATS下胸腺扩大切除治疗重症肌无力,技术是安全、可行的,具有创伤小、痛苦轻、并发症少、疗效可靠等优点,临床应用前景良好.     

Video-assisted thoracoscopy thymectomy for myasthenia gravis.

Over the past 8 years, the technique of video-assisted thoracoscopic surgery (VATS) thymectomy has continued to evolve. Although the procedure has become better defined and greater experience has been gained, numerous issues still exist. Whether it is best performed through a left sided, right sided, or as a bilateral approach with or without a cervical incision, is not clear. Equivalence of outcomes compared with more standard approaches to thymectomy is still an issue. Experience still is relatively limited to a few centers, and follow-up still is relatively short. In the author's own experience, it seems that availability of the less invasive approach has allowed thymectomy to be performed earlier in the course of the disease especially in young female patients in whom cosmesis is an important issue.     

Extended trans-sternal thymectomy for myasthenia gravis.

Otto reported thymectomy under transverse sternotomy. It currently is not a widely used procedure, however. Jaretzki graded the completeness of removal of thymic tissue as follows: maximal thymectomy 98% to 100%, extended thymectomy 85% to 95%, modified transcervical thymectomy (Cooper) 75% to 80%, VATS thymectomy 80% to 85%, simple trans-sternal thymectomy 70% to 75%, and simple transcervical thymectomy 40% to 50%. The results of each procedure do not always reflect the completeness of removal. The tables show that the most widely accepted procedure is the extended thymectomy, and the results of it are prominent and stable. Why do the results of the maximal thymectomy, however, not exceed those of the extended thymectomy? It is supposed that quantitative increase of removed thymic tissues in the maximal thymectomy might be minimal.     

Anesthesia for transcervical thymectomy in myasthenia gravis.

This review of anesthetic experience in 100 cases of transcervical thymectomy for myasthenia gravis (MG) at The Mount Sinai Hospital (1970-1974) underlines current trends in the surgical management at Mount Sinai, where transcervical thymectomy is the procedure of choice for all patients with nonthymomatous MG and for selected patients with thymomatous MG. The transthoracic approach is now limited to malignant thymomas and tumors not accessible through the transcervical approach. Formerly, patients coming for thymectomy either already had a preexisting tracheostomy, or an elective tracheostomy was performed at the time of thymectomy. Since 1972, none of these patients has had elective tracheostomy at the time of operation, and only four were performed in the postoperative period, patients being intubated orotracheally at the time of operation. The tube is usually removed within 1 hour after completion of thymectomy. All patients are followed in the intensive care unit for 24 hours or longer, under close supervision of experienced personnel aware of the inherent problems and able to assist ventilation at any stage. This approach has greatly changed the postoperative course of this disease.     

Anaesthesia for trans-sternal thymectomy in myasthenia gravis.

A retrospective review is presented of the thirty patients who underwent trans-sternal thymectomy for myasthenia gravis in our unit from 1980-85. The clinical status of these patients is contrasted to that of more severely debilitated patients described by other authors. The problems encountered by the anaesthetist in the perioperative care of patients with mild myasthenia gravis are discussed. Management of the perioperative anticholinesterase regime is described and a case presented for the use of suxamethonium for intubation. A less invasive postoperative regime is advocated in which tracheostomy and nasotracheal intubation are avoided, and anticholinesterase therapy is re-introduced orally as soon as possible after surgery.     

Isoflurane for thymectomy in myasthenia gravis

The clinical and electromyographic effects of isoflurane were studied in eight myasthenic patients undergoing trans-sternal thymectomy. After inhalational induction of anaesthesia, intubating and operating conditions were good. Recovery from anaesthesia was rapid with minimal postoperative residual muscle weakness or respiratory depression. All patients were extubated within the first postoperative hour. Integrated electromyographic monitoring of the train-of-four response of adductor pollicis demonstrated that myasthenics are more sensitive than nonmyasthenics to the neuromuscular depressant effects of isoflurane. Recovery of the integrated electromyographic response was incomplete despite a satisfactory clinical recovery.     

Effects of thymectomy in myasthenia gravis.

Factors influencing onset of remission in myasthenia gravis were evaluated in 2062 patients, of whom 962 had had thymectomy. Multivariate analysis showed that appearance of early remissions among all patients was significantly and independently influenced by thymectomy, by milder disease, and by absence of coexisting thymomas. Patients with mild generalized symptoms treated with thymectomy reached remission more frequently, even when compared with those with ocular myasthenia treated without surgery. Short duration of disease before thymectomy in mild cases was another factor associated with earlier remissions. Mortality for all patients was significantly and independently influenced by severity of symptoms, age, associated thymomas, and failure to remove the thymus. Patients without thymectomy and with thymomas had, in addition, earlier onset of extrathymic neoplasms. Morbidity after the transcervical approach was minimal. This study demonstrates that early thymectomy by the transcervical approach, when technically feasible, has significant clinical advantages over the transthoracic approach and should be advocated for all patients with myasthenia gravis, including those with ocular disease.     

Trans-sternal thymectomy in myasthenia gravis

Between 1986 and 1989 27 patients with myasthenia gravis underwent radical thymectomy: 24 patients without and two patients with thymoma through a trans-sternal incision, another with thymomatous myasthenia through a left-sided thoracotomy. The patients were staged according to the modified Ossermann classification. The results were evaluated prospectively according to the Disability Status Scale of Oosterhuis. During a mean follow up of 22.4 months, 21 patients (77%) benefited from the operation with complete remission achieved in 9 (33%) and significant improvement noted in 12 (44%). There were no operative deaths and no hospital morbidity. The mean operation time was 88 minutes, the mean postoperative hospital stay 10.5 days. These results support the recommendation for radical trans-sternal thymectomy in the treatment of patients with myasthenia gravis as a safe procedure.     

电视胸腔镜胸腺切除治疗重症肌无力症

目的探讨电视胸腔镜手术(video-assisted thoracoscopic surgery,VATS)胸腺切除治疗重症肌无力症(myasthenia gravis,MG)的可行性. 方法 18例MG采用VATS经右胸前侧径路行胸腺切除联合纵隔脂肪清扫. 结果 17例顺利完成手术,1例因电凝钩伤及左头臂静脉干而中转开胸止血.平均手术时间105 min,术中失血量平均80 ml.全组无术后死亡及危象发生.18例随访1～20个月,平均11.3个月.按Osserman疗效评价,缓解5例(27.8%),明显改善6例(33.3%),部分改善4例(22.2%),无变化3例(16.7%),有效率83.3%(15/18). 结论 VATS经右胸前侧径路行完全胸腺切除可行,且具有创伤小、恢复快等优点.