Abstract:
Background: Historically, ventriculoperitoneal shunting (VPS) has been the method of treatment for hydrocephalus in infants. Overtime, endoscopic third ventriculostomy with choroid plexus cauterization (ETV with CPC) has gained popularity with improved technology and technique. Aim: The purpose of this systematic meta-analysis is to compare the surgical procedures based on their efficacy, complications, and mortality rates. Methods: The systematic review used two electronic databases with a date restriction of the past five years and using the search terms endoscopic third ventriculostomy, ventriculoperitoneal shunting, hydrocephalus surgery, and choroid plexus cauterization. Results: The systematic review shunt related mortality rate ranged from 1.8-8%. The ETV surgical mortality rate ranged from 0-5.6%. The mean ETV short term success (event-free) rate at three – six month follow up was 75.8%. The mean VPS short term success (event free) rate at one year follow up was 68.9%. The mean rate of ETV failure requiring subsequent surgery was 23.4%. Of the studies in the systematic review that mentioned VPS failure requiring repeat revision, a mean VPS failure rate of 27% was found. Limitations: The articles in this review vary in follow up especially when comparing the availability of long-term studies of ETV outcomes compared to shunting. Conclusion: ETV has proven to be a safe and efficacious treatment option for hydrocephalus. A larger scaled prospective randomized control study is recommended to further determine the preferred treatment option for infantile hydrocephalus.
Key Words: ventriculoperitoneal shunt (VPS), endoscopic third ventriculostomy (ETV), choroid plexus cauterization (CPC), choroid plexus, pediatric hydrocephalus, hydrocephalus, head circumference, intracranial hemorrhage, increased intracranial pressure
Introduction:
Hydrocephalus is a condition described as the accumulation of cerebrospinal fluid in the ventricles of the brain.1 The buildup of CSF occurs when there is a disparity in the production and absorption which can lead to increased cranial pressure.2 Neonates and infants with hydrocephalus often have a normal cranial pressure due to compensatory mechanisms.1 Congenital hydrocephalus is caused by a number of etiologies with an incidence of three to four per one thousand births.3 Historically, infants with hydrocephalus have been treated surgically with the placement of a ventriculoperitoneal shunt to create a diversion of CSF into the peritoneum. Over the past two decades, improvements in technology have allowed for significant advancements in the approach to managing hydrocephalus in infants.1 The newer endoscopy techniques and equipment have made endoscopic third ventriculostomy a substantial alternative to shunting2. The method of choice in the treatment of communicating and non-communicating hydrocephalus in infants remains unclear. The purpose of this systematic review is to determine the method of choice for treating hydrocephalus in infants.
Synthesis:
The articles in this systematic review each contribute a clinical analysis of either VPS or ETV as a surgical treatment option for hydrocephalus. The results of these articles were therefore divided by the surgical treatment evaluated. A comprehensive, in-depth review of each study’s results was conducted, and results related to the efficacy, complications, and mortality were noted. Study size and significant study factors were noted to provide a fair evaluation in the comparison of the surgical options.
Endoscopic Third Ventriculostomy:
(Breimer GE, 2013 Study) In 2013 Breimer conducted a clinical study on efficacy of ETV. Effiacy was analyzed by short term (six months) and long term (thirty-six months) follow up. At 6 months, the overall ETV success rate was 70.2%. The remaining 29.8% at six months required subsequent treatment including VP shunt implantation/revision (93.5%) or repeat ETV (6.5%) for early ETV failure. In 84 out of 104 patients, a follow up period of at least 36 months was available. The overall ETV long term success rate after 36 months reduced to 48.8%. Between six and thirty-six months, 43 patients underwent consequential treatment for late ETV failure. Of the late ETV failure patients, 62.8% received VP shunt implantation and 37.2% underwent repeat ETV. Mortality: Ten patients died before the six month follow up, but the study did not clarify if their death was related to surgery or other causes. The mortality rate during the follow up period was 11.5%, however, only one of twelve patients died of shunt dysfunction and remaining eleven died due to cause unrelated to hydrocephalus treatment. Mortality rate of this study was therefore determined as 1%.6
(Arijpour M, 2015 Study) A case control study included 45 patients < 12 months of age with hydrocephalus 15 of which underwent endoscopy surgery via minicraniotomy and the control group of 30 patients underwent endoscopic surgery through a burr hole. Among the minicraniotomy group, 13% developed a CSF collection complication compared to 26% of the burr hole control group. One patient of the burr hole control group developed meningitis and one patient of the burr hole control group experienced CSF leakage. Zero patients of the minicraniotomy group developed infection. There was no surgical mortality in this study.7
(Ojo OA, 2015 Study) In this clinical study, 34 patients with hydrocephalus were followed post-ETV for six months in the tertiary developing country of Nigeria. The ETV success rate at six months was reported 73.5%. Out of the 26 successful ETV follow ups, (73.1%) were six months or less of age. Poor outcome at follow up was defined as death or complication requiring surgery. Of the poor outcome follow ups, 89.5% were six months or less of age. The mean age of patients with successful ETV at six months follow up was 4.8 months compared to those with ETV failure which was 2.8 months. The patient cases were divided based on etiology of hydrocephalus. Nine hydrocephalus patients post meningomyelocele surgery had 100% success rate. Three post infectious hydrocephalus patients had successful ETV follow up and two patients failed ETV. Of the 70% of the non-post infective and non-postsurgical hydrocephalus had a successful ETV. Mortality: 5.8% died within three months post-ETV.8
(Schulz M, 2015 Study) A retrospective clinical study involved the observation of nine patients who underwent a stented ETV. Symptoms resolved in 77.8%. One patient experienced failed sETV requiring subsequent treatment. There was no surgical mortality reported in this clinical study.9
(Vulcu S, 2015 Study) A large case series of 113 patients who underwent ETV for obstructive hydrocephalus were evaluated for short-term (three months) outcomes and long-term (average seven years) outcomes. The success rate at the short term follow up was 82%. A decrease in success rate was reported as 78% at the long-term follow up. Overall the ETV failure rate was 27.4% and those patients required a second ETV or shunt treatment. 4% experienced an intraoperative complication of intraventricular hemorrhage or paroxysmal tachyarrhythmia. Transient post-operative complications were seen in 4% including wound infection, bacterial meningitis, phlebothrombitis, and pneumonia. Four out of five post-operative complications had no effect on long term ETV success. The etiology of hydrocephalus and age at surgery were evaluated based on success rate. Intraventricular cyst hydrocephalus patients showed the best long-term ETV success rate (91%.) Those with tumor related hydrocephalus had a success rate of 57% and history of infection/bleed had the poorest success rate of 46%. Mortality: Two patients died during their post-operative hospital stay one due to cardiac arrest and the other tumor progression, resulting in a surgical mortality rate of < 1%.10
Ventriculoperitoneal Shunting:
(Khan F, 2013 Study) The study of 113 hydrocephalus patients treated with VP shunting had an overall shunt failure rate of 23% requiring shunt revisions. 80.1% of the shunt revisions were done within the first-year post-operative. 15.1% of patients experienced shunt obstruction and 8% developed shunt infection. The etiology of hydrocephalus was shown to have an effect on shunt efficacy. 45.5% patients with hydrocephalus post-meningitis experienced shunt failure. Patients delivered via caesarean section were seen to have higher rate (p = 0.036) of shunt failure than those delivered vaginally. The mortality rate of this study was 1.8%.11
(Paulsen AH, 2015 Study) This retrospective study provided long-term surgical outcomes and mortality rate. 128 pediatric patients who underwent shunting for hydrocephalus were followed over a 42-45-year period. 61 out of 128 patients died, 22 of which had hydrocephalus secondary to a brain tumor. The mortality rate at one year was 16% with an increasing rate up to 48% at 40 years. However, the cause of death was not mentioned in the study. Within the last ten years, 21 patients underwent a total of 41 shunt revisions. One patient died from acute shunt failure 20 years after the primary VP shunt placement. The shunt related mortality rate was 8%. 3
(Wang JY, 2017 Study) This study specifically analyzed the shunting outcomes of 69 post hemorrhagic hydrocephalus infants. The study showed a VPS success rate of 73.6% at year one. The success rate declined to 44.1% at 5 years and then to 36.7% at 10 years. No factors were found to have a significant effect on time of shunt failure. 47.8% of patients required at least one shunt revision. 10 out of 69 patients required a late shunt revision at least three years after the primary VP shunt surgery. Ten patients developed a shunt infection, requiring revision. 31 patients experienced proximal catheter shunt occlusion and 14 experienced distal catheter occlusions. Mortality was not mentioned in this study.12
(Pylvanen V, 2018 Study) In this retrospective study 137 patients were followed after primary VPS placement. By the six months follow up, 6.5% of patients required a shunt revision due to complication. The overall shunt complication rate was 35.76%. Shunt revision was required in 27% of the patients. 16.7% of patients required one shunt revision; 8% of patients required two shunt revisions; 2% of patients required three shunt revisions. The two most common shunt complications in the study were obstruction (45.94%) and infection (16.21%). The hydrocephalus patients post-tubercular meningitis (35.13%) and intraventricular hemorrhage (45.4%) were seen to have the highest rate of multiple shunt revisions. The mortality rate in this study was 5.1%.13
(Chugh A, 2018 Study) Although a small study of nine patients, this study provides an analysis of the high-risk complication, VP shunt extrusion, and its post-complication outcomes. Three patients required shunt removal due to extrusion and subsequently underwent ETV. The three patients with an abdominal wall extrusion developed an infection but no CSF drainage. Two of the infected abdominal wall extruded VPS patients developed meningitis and an abscess in the shunt tract requiring intervention. Transvaginal and transanal extrusion of the VPS distal catheter with sterile CSF was seen in five patients. Mortality was not mentioned in this study.14
Table 1 Review of Articles
Author, Year Published
# Subjects
Results
Endoscopic Third Ventriculostomy
Breimer 2013 [6] 104 ETV success rate (6 months) 70.2%
29.8% required subsequent surgical treatment
10 pts died before the 6 months follow up
Arjipour, 2015 [7] 45 13% of minicraniotomy group developed complications
26.7% of the burr hole control group developed complications
Ojo, 2015 [8] 24 ETV success rate (6 months) 73.5%
100% of post meningomyelocele patients had successful ETV
60% post infectious hydrocephalus patients had successful ETV
70% non-post-infectious and non-post-surgical patients had successful ETV.
5.8% mortality rate
Schulz, 2015 [9] 9 77.8% resolution of clinical sx (nausea, vomiting, headache, loss of consciousness)
No operative morbidity
1 failed ETV due to poor control of hydrocephalus
Vulcu, 2015 [10] 113 ETV success rate (3 months) 82%
Long term ETV success rate (average 7 years) 78%
27.4% ETV failure and required second surgery
Ventriculoperitoneal Shunting
Khan, 2013 [11] 113 26 VPS revisions; 21 revisions within 1 yr.
C section delivered patients significant influence on median shunt survival (p=0.036)
Overall rate of shunt failure 23%
Mortality rate of 1.8%
Paulsen, 2015 [3] 128 47.6% mortality: lowered to 39% if tumor related hydrocephalus excluded
Overall mortality rates at 1yr (16%), 2 yr. (24%), 10 yr. (31%), 20 yr. (40%), and 40 yr. (48%)
Shunt related mortality 8%
41 shunt revisions in 21 patients performed in last decade
1 pt died due of acute shunt failure in the later time period
Wang, 2017 [12] 89 47.8% required at least 1 shunt revision
26.1% required > 1 revision
VPS success rate (1 year) 73.6%
MCC shunt revision 47% obstruction and 15.2% infection
28 pts required revision in first 3 years
10 pts required revisions after 10 yrs.
Pylvanen, 2018 [13] 137 VPS success rate (1 year) 56.12%
Long term VPS success rate (5 years) 37.7%
23 pts required 1 shunt revision, 11 pts 2 shunt revisions, 3 pts 3 shunt revisions
Complications: 67.56% mechanical and 16.2% infective complications
Shunt related mortality 5.1%
Chugh, 2018 [14] 8 3 abdominal wall extrusion + infection
5 transvaginal and trans anal extrusion + CSF drainage
3 required shunt removal after extrusion + underwent ETV
Discussion:
Based on the systematic review, further studies are warranted to determine the treatment of choice for hydrocephalus in infants. A prospective randomized control study is recommended to determine the efficacy and safety of ETV/CPC compared to VPS in the treatment of hydrocephalus in infants.5 There remains a gap in data for long term (ten plus years) success of ETV, thereby limiting the comparison to VPS.5 It is advised that treatment success in specific etiologies of infant hydrocephalus are compared to establish a clinical prognostic rule to assist in the decision-making process of the appropriate surgical technique.3 At this time, clinicians should continue to practice the current evidence-based medicine and utilize endoscopic third ventriculostomy if resources and presentation are suitable. The specific conditions and anatomical abnormalities in which shunting is recommended should continue to be practiced until further research is conducted.8
Conclusion
Hydrocephalus is a common disorder that carries a high risk for mortality and a need for surgical management. The ETV surgical option was proven to be safe and efficacious in all five ETV focused articles in this review.6-10 There is a significant association between risk of shunt complications and etiology of hydrocephalus that should be further evaluated to determine the preferred surgical option for specific etiologies of infantile hydrocephalus.3 This meta-analysis showed VPS to have a higher rate of mortality and complications compared to ETV, however, it is important to consider the lack of long term follow up in the ETV patients.