Surgical Management of Spinal Dysraphism : Five-year Experience in a Central Hospital

Introduction: Spinal dysraphism is a heterogeneous group of congenital spinal anomalies resulting from defective closure of the neural tube early in fetal life and anomalous development of the caudal cell mass. Meningomyelocele is common among Neural tube defects. Patients with myelomeningocele present with a spectrum of impairments, including primary functional deficits like are lower limb paralysis, sensory loss, bladderbowel dysfunction and cognitive dysfunction. Medical, surgical management and rehabilitation have helped patients with neural tube defects to participate and be productive in mainstream society. The aims of this study were to review the clinical presentation, surgical management and their outcome in the patient with spinal dysraphism. Materials and Methods: This is a retrospective study of Forty-one cases of spinal dysraphism managed during a period of five years from January 2008 to December 2012 in Department of Neurosurgery, National Academy of Medical Sciences (NAMS), Bir Hospital. Demographic profiles, clinical presentation of patients with spinal dysraphism, associated hydocephalus, surgical management and outcome were studied. Results: Out of total 41 cases studied, male patients outnumbered female with 58.5% to 41.5%. Age ranged from 5 days to 29 years and mean age was 2.71 years whereas. Lump (97%) and paraparesis (88%) were frequent mode of presentation. Lumbar lesion (65%) was commonest followed by lumbosacral (29%). Hydrocephalus was present in 51% of cases and in 24% cases developed hydrocephalus later after repair. Total 75.6% of cases were treated with VP shunt. Conclusion: Spinal dysraphism is debilitating entity and management is challenging. Lump on back and weakness of limb are major factor for children and their parents seek medical service. Lesion in low back (lumbar and lumbosacral) were most common location. Besides repair, majority of them needed CSF diversion surgery for hydocephalus. Aim of surgical management was to prevent further deterioration, control of hydrocephalus or leak.


Introduction
S pinal dysraphism, or neural tube defect (NTD), is a broad term encompassing a heterogeneous group of congenital spinal anomalies that result from defec ve closure of the neural tube early in fetal life and anomalous development of the caudal cell mass 1,2 . The prevalence of NTDs varies widely between 1 and 10 per 1,000 births, depending on geographic region and ethnical grouping, making them one of the most frequent congenital malforma ons 3 . In Nepal, a demographic and health survey 4 reported incidence of NTD is 47/10,000 live birth. Word "Spinal Dysraphism" was coined by B W Leichenstein in 1940. NTDs can be classifi ed as "open" NTDs in which the neural ssue is exposed and "closed" NTDs with the neural ssue covered by ssue 5,6 .
Pa ents with myelomeningocele present with a spectrum of impairments, including primary func onal defi cits like lower limb paralysis, sensory loss, bladderbowel dysfunc on and cogni ve dysfunc on 7 . Pa ents with neural tube defects are par cipa ng and can be produc ve in mainstream society if proper treatment and care given to them. However, medical, surgical, and rehabilita on issues arise in the pa ent with myelomeningocele from birth through adulthood. The anatomic level of the myelomeningocele sac roughly correlates with the pa ent's neurologic, motor, and sensory defi cits 9 . This condi on is associated with several CNS malforma on (Chiari II), cardiac anomalies, cle lip and palate and genitourinary tract anomalies 10 .
Besides folic acid defi ciency, e ology in most cases of myelomeningocele is mul factorial, involving gene c, racial, and environmental factors (e.g., teratogens). Intrauterine exposure to an epilep c drugs, par cularly valproate and carbamazepine, and to drugs to induce ovula on are iden fi ed risk factors 11,12,13 . Research in the 1980s showed correc on of folic acid defi ciency as an eff ec ve means of primary and recurrent preven on 14 . A 2008 study es mated that for fi ca on programs prevent about 22,000 cases, or 9% of the es mated folic acid-preventable spina bifi da and anencephaly cases in United states 15 .
The aim of this study were to review the clinical profi le, presenta ons of pa ents with spinal dysraphism in our region, surgical management, its' associa on with hydrocephalus and their outcome in the pa ent.

Material and Methods
This was a retrospec ve study of 41 cases of spinal dysraphism managed during period of fi ve years from January 2008 to December 2012 in Department of Neurosurgery Na onal Academy of Medical Sciences (NAMS), Bir Hospital. All meningomyelocele, meningocele from cervical to sacral region operated in this ins tute were included in this study. Spina bifi da occulta, encephalocele and cases of tethered cord previously operated in other centres were excluded from the study. Demographic profi les, clinical presenta on, surgical management, outcome of these cases were studied.

Results
Forty-one cases were studied. Mean age at presenta on was 2.71 years with age ranging from 5 days to 29 years ( Figure 1). Male and female pa ents were 58.5% and 41.5% respec vely.    Ventriculoperitoneal (VP) Shunt was required in 31 (75%) cases, 21 (51%) cases had concurrent hydrocephalus and 10 (24%) cases developed hydrocephalus a er repair. In 80% cases primary closure was possible. Rest needed reinforcement with paraspinous fascia. CSF sent for rou ne inves ga on a er each VP shunt found to be normal, so infec on was not the cause for hydrocephalus before or a er repair of MMC.
Eight cases where subarachnoid lumbar drain was kept per opera vely, two needed VP shun ng. Lumbar drain prevented wound site CSF leak. Two cases with CSF leak was managed with primary closure of leak, intravenous an bio c and later they were shunted (VP Shunt) as they developed hydrocephalus. One developed shunt infec on which was managed ini ally with external ventricular drain and later VP Shunt.

Discussion
The incidence of spinal dysraphism is approximately 1 per 1,000 live birth 16 . This declined 50% between 1970 and 1989 (0.6-1.3 cases per 1000 live births) in the United States. 17 Despite aggressive medical care, 10-15% of these children die prior to reaching the fi rst grade. However, most children with isolated myelomeningocele (without major anomalies of other organs) survive to adulthood, and life expectancy is nearly normal 18 . The most common presenta on of a closed NTD is an obvious abnormality along the spine such as a fl uid-fi lled cys c mass, area of hypopigmenta on or hyperpigmenta on, cu s aplasia, congenital dermal sinus, capillary telangiectasia/ hemangioma, hairy patch (hypertrichosis), skin appendages, or asymmetrical gluteal cle 19 . The birth prevalence rate of myelomeningocele was slightly higher in females than in males (1.2:1), based on data from state and na onal surveillance systems from 1983-1990 10 . In this study males outnumbered female with ra o of 1.4:1.
In a fetal ultrasonographic study done to detect congenital anomalies, defects were located in lumobsacral region in 90% of cases, in thoracic region 6-8%, and in cervical vertebrae 2-4% 17 . In a study of north India, 20  . In a series, 21 most common loca on was lumbosacral (44%) followed by dorsolumbar (32%). In this study, commonest site (Table 4) was lumbar (66%) and Lumbosacral regions (29%). In about 90% of the children with myelomeningocele, hydrocephalus also occurs because the displaced cerebellum interferes with the normal fl ow of cerebrospinal fl uid, causing an excess of the fl uid to accumulate 22 . In this study total of 31(75%) cases needed VP shun ng (Figure 4). Among them 10 (24%) developed hydrocephalus a er repair. In 8 cases, lumbar drain was kept in subarachnoid space peropera vely and kept for 5-7 days. This helped in preven on of CSF leak. In this study, VP shunt was performed for cases with HCP in emergency and repair done as elec ve. Emergency repair is the protocol for ruptured meningomyelocele to prevent meningi s and hypoten on.

Future perspective
In Europe, open fetal surgery for spina bifi da was introduced in 2003 by the Polish paediatric surgeon Janusz Bohosiewicz in Katowice. Through the end of 2011, more than 40 fetuses with spina bifi da were operated at that center 23 . Experience on endoscopic fetal surgery was presented at various na onal and interna onal mee ngs but its clinical introduc on was aff ected by technical diffi cul es and a number of adverse fetal outcomes 24 . Such advanced foetal surgery facili es are yet to be set in our region. As a part of preven ve program in rural Nepal, Micronutrient Ini a ve (MI) began working with village millers to help them add essen al vitamins and minerals to the cereal fl our they produce since 2007 25 .

Conclusions
Spinal dysraphism is debilita ng en ty and management is challenging. Lump on back and weakness of limb are major factor for children and their parents seek medical service. Lesions in low back (lumbar and lumbosacral) were most common loca on. Besides repair, majority of them needed CSF diversion surgery. Aim of surgical management was to prevent further deteriora on and control of hydrocephalus or leak.