It is recommended that myelomeningocele repair should be performed as soon as possible after birth to minimize the risk of infection, mortality, and possible spinal cord dysfunction. Contrary to the expectations, it is not strange to encounter suprising results
3. Moreover, the first 72 hours after birth are accepted as the safe period for MMC repair
1. After this period, the infection risk is reported to be significantly high (4,5). Regarding this issue, the ratio of ventriculitis (37%) at late stage repair has been reported by McLone
6 is remarkable. There have been reports stating that no significant differences were observed for the risk of infection in timing of MMC repair
7. When our study was compared with the literature, in spite of our late repair of sac (after 3 days), our infection risk didn't have high ratio (12%). The effectiveness of new generation antibiotics is thought to play a role in this concept
8. Another controversial issue related with infection risk is the timing of the shunt operation. Three different approaches may be performed; before, at the same session, and after sac repair. Shunting before sac repair significantly increases the risk of central nervous system infection
1. In addition to the possible effects of HCP on brain parenchyma, progression caused by Chiari and the negative effects on wound healing after sac repair resulted in the widespread preference to perform shunt and sac repair at the same session in the 1980s
2,9,10. In these studies, it was stated that simultaneous sac repair and shunt operations caused no risk for infection. Chadduck et al.
9 reported a low risk of infection as 5% in the long-term. In following years, these results were supported with larger series
11-13. On the other hand, some authors believe that this approach results in increased risk of infection by CSF backflow from the sac into the ventricles
11. In any case, MMC is generally believed to increase shunt infection risk. In the reports of Mirzai et al.
14, the rate of shunt infection was 24%. In this study, MMC repair was performed on 47% of cases on the first day of life and it was reported that delayed repair increased the rate of infection.
Oktem et al.15 emphasized that VP shunt placement in the same session may be more advantageous for the patient, family, and physician and also from economic view, however they believed that VP shunt insertion should be performed in another session following MMC sac repair after excluding the presence of infection, especially in cases with a perforated MMC sac.
In the present study, the shunt infection ratio was 12% in 50 cases with late-period sac repair. The most important result of our study is that the ratio of infection in cases with sac repair performed after 10 days was about 6,9%. Despite the effectiveness of the surgical technique and prophylactic antibiotics on this decrease in infection ratio, it should not be forgotten that these cases are sensitive to infections in the physiological adaptation process between intrauterine and newborn periods16. Higher infection rates have been reported in myelomeningocele cases undergoing shunt operation in the first week after birth, than others undergoing shunts at later stages17. In 4 cases with shunt infection, MMC repairs were performed between the 4th and 10th days after birth. This was 19% of 21 cases with MMC repair between the fourth to tenth days. Shunt infection was observed in only two cases with myelomeningocele repair after 10 days (6,9%). When all these data were linked, we consider that sac repair in addition to shunting between the fourth and tenth days, is significant for the risk of shunt infection. These results support the reports of Amiratti et al17. In contrast to the study by Amiratti et al, we want to especially emphasize that our study only included cases with late period MMC sac repair. Considering these 21 cases, simultaneous and consecutive shunting and sac repair were not significant for the risk of infection.
In conclusion, the risk of shunt infection for late period (after the third day of the birth) MMC sac repair is higher between the 4th and 10th days. There was no statistically difference between the risk of infection and the timing of shunt application (in same or different session) at late stage myelomeningocele repair.