Difficult Decisions in Minimally Invasive Surgery of the Thymus

A minimally invasive resection of thymomas has been accepted as standard of care in the last decade for early stage thymomas. This is somewhat controversial in terms of higher-staged thymomas and myasthenia gravis patients due to the prognostic importance of complete resections and the indolent characteristics of the disease process. Despite concerted efforts to standardize minimally invasive approaches, there is still controversy as to the extent of excision, approach of surgery, and the platform utilized. In this article, we aim to provide our surgical perspective of thymic resection and a review of the existing literature.

Thymectomy in Myasthenia Gravis

In recent years, thymectomy has become a widespread procedure in the treatment of myasthenia gravis (MG). Likelihood of remission was highest in preoperative mild disease classification (Osserman classification 1, 2A). In absence of thymoma or hyperplasia, there was no relationship between age and gender in remission with thymectomy. In MG treatment, randomized trials that compare conservative treatment with thymectomy have started, recently. As with non-randomized trials, remission with thymectomy in MG treatment was better than conservative treatment with only medication. There are four major methods for the surgical approach: transcervical, minimally invasive, transsternal, and combined transcervical transsternal thymectomy. Transsternal approach with thymectomy is the accepted standard surgical approach for many years. In recent years, the incidence of thymectomy has been increasing with minimally invasive techniques using thoracoscopic and robotic methods. There are not any randomized, controlled studies which are comparing surgical techniques. However, when comparing non-randomized trials, it is seen that minimally invasive thymectomy approaches give similar results to more aggressive approaches.

Rocuronium and sugammadex in patients with myasthenia gravis undergoing thymectomy

BACKGROUND

The use of neuromuscular blocking agents is still controversial in myasthenic patients but rocuronium could be useful after the introduction of sugammadex as a selective antagonist. The aim of the study was to evaluate the use of rocuronium-sugammadex in myasthenic patients undergoing thoracoscopic thymectomy.

METHODS

After ethical approval, 10 myasthenic patients undergoing videothoracoscopic-assisted thymectomy were enrolled in the study. Neuromuscular block was achieved with 0.3 mg/kg rocuronium and additional doses were given according to train-of-four (TOF) monitoring or movement of the diaphragm. Sugammadex 2 mg/kg was given after surgery. Recovery time (time to obtain a TOF value > 0.9) was recorded for all subjects.

RESULT

All patients were extubated in the operating room after administration of sugammadex. Mean rocuronium dose was 48 mg and the average operation time was 62 min. Recovery time after sugammadex administration was 111 s (min 35; max 240).

CONCLUSIONS

A rapid recovery of neuromuscular function was found in myasthenic patients receiving rocuronium when sugammadex was used for reversal. This combination could be a rational alternative for myasthenic patients for whom neuromuscular blockade is mandatory during surgery.

A standardized protocol for the perioperative management of myasthenia gravis patients. Experience with 110 patients

BACKGROUND

Video-assisted thoracoscopic extended thymectomy (VATET) is well established in the treatment of myasthenia gravis; however, patient selection remains controversial. Perioperative management protocol is lacking, and concerns regarding post-operative myasthenic crisis still remain. We performed a retrospective observational study evaluating the impact of the introduction of a protocol in the perioperative management of patients with myasthenia gravis who underwent VATET.

METHODS

The perioperative management protocol was developed by a team of neurologists and anesthesiologists who reviewed the literature and their previous experience on myasthenia gravis patients. Respiratory, clinical, and neurological patient features were included in the protocol evaluation. A retrospective review of patients who underwent VATET before and after introduction to the protocol was finally performed.

RESULTS

The medical records of 66 patients (pre-protocol group) and 44 patients (protocol group) were available for the study. In the pre-protocol group, 17 patients (26%) were admitted to intensive care unit (ICU) during the post-operative period, while three patients (6.8%) of the protocol group met the criteria for ICU post-operative admission. This resulted in a reduction of 73.5% of patients admitted to ICU (P = 0.023) and in an 80% (P = 0.002) reduction of the use neuromuscular blocking agents. Two post-operative myasthenic crises preceded by bulbar symptoms (1.8%) were identified in the pre-protocol group patients.

CONCLUSIONS

Although the application of our protocol results in a substantial reduction in the recovery of patients in the ICU and in hospital costs, there was no substantial difference in mortality and morbidity between patients admitted to the surgical ward or to ICU.

Anesthesia and myasthenia gravis

Myasthenia gravis (MG) is a disease affecting the nicotinic acetylcholine receptor of the post-synaptic membrane of the neuromuscular junction, causing muscle fatigue and weakness. The myasthenic patient can be a challenge to anesthesiologists, and the post-surgical risk of respiratory failure has always been a matter of concern. The incidence and prevalence of MG have been increasing for decades and the disease is underdiagnosed. This makes it important for the anesthesiologist to be aware of possible signs of the disease and to be properly updated on the optimal perioperative anesthesiological management of the myasthenic patient. The review is based on electronic searches on PubMed and a review of the references of the articles. The following keywords were used: myasthenia gravis AND neuromuscular blocking agents, myasthenia gravis AND sevoflurane, myasthenia gravis AND epidural, myasthenia gravis AND neuromuscular blockade reversal and myasthenia gravis AND pyridostigmine. The articles included were from reviews and clinical trials written in English. MG patients can easily be anesthetized without need for post-surgery mechanical ventilation whether it is general anesthesia or peripheral nerve block. Volatile anesthesia or the use of an epidural for the patient makes it possible to avoid the use of neuromuscular blocking agents, and when used, it should be in smaller doses and the patient should be carefully monitored. This review shows that with thorough pre-operative evaluation, continuing the daily pyridostigmine and careful monitoring the MG patient can be managed safely.

Myasthenia gravis

OPINION STATEMENT

Treatment of patients with acquired (autoimmune) myasthenia gravis should rely on evidence-based therapeutic choices, taking into account the individual's needs according to disease severity (mild to severe), extent (ocular or generalized), comorbidities (including other autoimmune diseases, infections, thymoma, and pregnancy), age, iatrogenic factors (the risks and benefits of therapy), patient autonomy and quality of life, financial burden to the patient, and associated health care costs. Therapy is aimed at managing symptoms by improving neuromuscular junction transmission (cholinesterase inhibitors) and/or modifying the underlying immunopathogenetic cause of acquired myasthenia gravis via immunosuppression or immunomodulation. Myasthenic patients with operable thymoma should be referred for surgery and closely followed up for tumor recurrence. A concerted international effort is addressing treatment recommendations for thymectomy in myasthenic patients with no radiologic evidence of thymoma who are positive for circulating acetylcholine receptor antibodies. There is a lack of evidence-based treatment guidelines for both acute and long-term management of ocular myasthenia. Acute management of myasthenic crisis requires intensive monitoring of the patient and institution of an efficient and safe treatment such as plasma exchange. Patient education is essential to a comprehensive long-term treatment plan.

Effectiveness of basic endoscopic surgical skill training for pediatric surgeons

PURPOSE

Pediatric surgeons require highly advanced skills when performing endoscopic surgery, but their experience with such cases tend to be limited in comparison to general surgeons. The aim of this study was to evaluate the effectiveness of basic endoscopic surgery training for less-experienced young pediatric surgeons and then compare their skills with those of general surgeons.

METHODS

The surgeons (n = 477) subjected to this study underwent a 2-day endoscopic skill training program, consisting of lectures, box training, VR simulator training, tissue training, and live tissue training. The trainees were divided into two groups: P (pediatric surgeons, n = 33) and G (general surgeons, n = 444). The trainees were required to make a continuous suture along a circle measuring 2.5 cm in diameter and the findings were evaluated both before and after training. A statistical analysis was conducted using the unpaired t test.

RESULTS

The number of experienced cases totaled 20.8 ± 23.9 in P and 60.6 ± 80.5 in G (p < 0.001). The number of completed sutures before training was 1.4 ± 1.1 in P and 1.9 ± 1.5 in G (p < 0.05). The number of completed sutures after training was 4.1 ± 1.3 in P and 3.9 ± 1.9 in G (p > 0.05). The economy and speed of the forceps improved, however, the number of errors increased.

CONCLUSION

Less-experienced pediatric surgeons improved their surgical skill and ability until reaching almost the same level as that observed in more experienced general surgeons during training, however, the number of errors after training increased in comparison to before training. As a result, this program needs to be modified to reduce the number of errors while enabling pediatric surgeons to master the safe and precise surgical techniques needed in this field.