Our results show a remarkably high frequency of tracheostomies in patients whose GR was absent or brainstem was invaded, either compressed or infiltrated by the MB tumors. We found the incidence of tracheostomy requirement in our center for children undergoing MB tumor resection to be 26%, which is relatively high compared to previous studies (1.5%, 16%, and 6.4%)[4–6].
Tracheostomy placement may improve respiratory compromise caused by compression of the brainstem by MB tumor or resection operation. However, it is burdensome for the patient and family, challenges the clinical course and quality of life of the patients. A report suggests that it may adversely affect language development. Moreover, tracheostomy placement can cause infection, tracheoinnominate fistula, stress on caregivers, place patients at risk for longer hospital stays and death, and impose a great financial burden on patients, families, and the healthcare system[7–10].
An important consideration in interpreting the results is that in our center the standard of care for MB resection involves VP shunt insertion two weeks prior to final operation. Although not everyone will be shunt-dependent for the rest of their lives, VP shunt insertion has several advantages. It provides a period of time for healing of the shunt insertions site. Moreover, there is a risk of upward herniation associated with ETV endoscopic third ventriculostomy in posterior fossa tumor. To be brief, VP shunt application is more favorable in our setting unless proven otherwise. The dominant approach in resecting MB tumors in our center is the midline transvermian posterior fossa approach is the approach practiced by pediatric neurosurgeons in resecting MB tumors in our center.
Postoperatively, we tend to keep the patients intubated for approximately two weeks. Although early tracheostomy is supported, we take a more conservative stance toward tracheostomy. It was noted before that the tracheostomy requirement in patients with brainstem tumors reflects the interruption of respiratory pathways located there. After tumor resection, pressure on the nerves is reduced which might improve the lower cranial neuropathy and help the ventilation function to recover, particularly in pediatric patients. Besides, tracheostomy care is highly costly for the patients and not widely available. It is shown in the results that although the absence of GR is among the most common indications for tracheostomy. However, one-fourth of the patients with absent GR pre-operatively did not require tracheostomy after the operation. It is worth considering that in previous studies, 25% or more of the patients were decannulated one year after the tracheostomy [4, 5]. Moreover, once the course of tracheostomy is finished, a second tracheostomy is rarely needed. Recannulation rate in the pediatric setting was measured at 6.5 % .
It should be considered that all of the tumors resected in our center were greater than 5 cm in diameter. It points to the ineffective system for screening brain tumors in Iran, resource scarcity, and the long waiting lists.
The lack of an association between the extension of the tumors to CPA and cervical invasion and tracheostomy requirement likely represents the limitation of small sample size and outcome of interest. In previous studies, it was suggested that younger patients were more likely to require tracheostomy. However, the statistical difference between the younger and older patients requiring tracheostomy was not statistically significant.
The greatest limitation of the present is the retrospective design of this investigation. This study does not follow the patients long after the operation. The final outcome of the tracheostomies, whether the patients were expired or decannulated, is not reported. However, the sample size of this study is exceptionally large. Although the patients were not followed long after the operations, valuable factors predicting the requirement of post-operative tracheostomy were included and analyzed. This study can give insight to practitioners and help them to make informed predictions about their needs, patients who may benefit from early tracheostomy, the outcome of the operations, and reduce intubation-associated trauma and time on mechanical ventilation.
Finally, by comparing the results of the present study with similar reports, it becomes clear that an effective screening system is of utmost importance. If the tumors are diagnosed earlier and at a lower size, brainstem compression, infiltration and other indications for tracheostomy are less likely to develop. By doing so, we can improve the outcome of MB tumor patients and prevent tracheostomy which is highly burdensome financially, physically, and emotionally.