Incidence and clinical features of complicated hydrocephalus
From 2012 to 2017, about 54, 000 neurosurgical operations were performed in Beijing Tiantan Hospital, and VPS was performed in 1100 (2.0%) patients with hydrocephalus before or after tumor resection. Among VPS patients, 28 (2.5%) adult patients with complicated hydrocephalus were surgically treated with Y-shaped VPS. Clinical data are summarized in table 1 and table 2. The age of onset ranged from 17 to 68 years; the mean age was 37±14 years (all means are expressed ± SD). These patients included 16 males and 12 females. Pathology was available in 16 cases. Tumors were diagnosed as craniopharyngioma in 8 cases, glioma in 7 cases, pituitary adenoma in 3cases, colloid cyst in 2 cases, pineal parenchymal tumor of intermediate differentiation in 2 cases, malignant teratoma in 2 cases, central neurocytoma in 1 case, epidermoid cyst in 1 case, meningioma in 1 case, and pinealocytoma in 1 case.
Radiological features of complicated hydrocephalus
Tumor was located in the 3rd ventricle involving Foramen of Monro in 8 cases, 6 cases in the suprasellar region involving the 3rd ventricle, 4 cases in the sellar region involving the 3rd ventricle, 4 cases in the pineal region, 2 cases in the bilateral thalamus and hypothalamus, 1 case in the right ventricle, 1 case in the trigone of the left ventricle, 1 case in the right temporal lobe, and 1 case in bilateral ventricles and 3rd ventricle. Hydrocephalus before tumor resection/stereotactic biopsy was identified in 24 cases, including 23 bilateral and 1 unilateral. Hydrocephalus after tumor resection was in 9 cases, including 5 bilateral, 2 triple and 2 unilateral (contralateral hydrocephalus after unilateral VPS).
Surgical technique of Y-shaped shunt
Figure 1A-1C illustrates the position and the shape of skull incisions for bilateral frontal horn shunts. Two symmetrical incisions (3cm) are 2.5cm parallel to the midline, with the midpoint 2.5cm from the hairline. One incision (3cm) was on the parietal protuberance along with the temporal line. Figure 1 D and 1E illustrates the main procedure of connecting two or three catheters to the Y-shaped connector, respectively. The procedure was as the following. a. puncture the entrapped ventricular apartments and subcutaneously guide the catheters to the incision on the parietal protuberance. b. abdominal skin incision and guide the peritoneal catheter to the incision on the parietal protuberance. c. connect the Y-shaped connector to the peritoneal catheter. d. then connect the Y-shaped connector to the ventricular catheters, avoiding folding of the catheters and connectors. e. make sure the smooth CSF drainage and place peritoneal catheter into the peritoneal cavity.
Y-shaped shunt for complicated hydrocephalus before or after tumor surgery
The treatment chart was shown in Fig 2. Of 24 cases with pre-op. hydrocephalus, 19 underwent Y-shaped VPS before or without tumor resection/stereotactic biopsy. All the ventricular tips were in the bilateral frontal horns. Tumor resection was performed in 12 cases, stereotactic biopsy in 4 cases, and no surgery in 12 cases. 7 patients underwent Y-shaped VPS after tumor resection, including 5 with double and 2 with triple ventricular tips. In 5 cases with double ventricular tips, bilateral frontal horns were punctured in 2 cases, frontal and temporal horns in 2 cases, frontal horn and subdural in 1 case. In 2 cases with triple ventricular tips, bilateral frontal horns with unilateral occipital horn were punctured in Case 6 and bilateral frontal horns with unilateral temporal horn were punctured in Case 7. Two patients underwent sequential Y-shaped VPS with duration of 6 months (Case 17 and 19). Case 17 without tumor resection suffered from contralateral hydrocephalus 6 months after unilateral VPS. Case 19 suffered from contralateral hydrocephalus 6 months after tumor resection and unilateral VPS. Contralateral ventricular tip was added to the original shunt by a Y-shaped connector and bilateral hydrocephalus was successfully resolved. Besides, programmable and anti-siphon shunt was chosen for 25 patients, and fixed shunt for 3 cases.
Surgical outcomes and complications
Patients’ status was improved in 25 cases and worsened in 3 cases. 4 patient received radiotherapy and chemotherapy, 1 received radiotherapy only, 2 received gamma knife, and 2 received stereotactic aspiration and inner radiotherapy. The other patients did not receive any other treatment except VPS. The Karnofsky performance ptatus (KPS) at the last follow-up ranged from 50 to 100, with the median of 90. Patients were followed 0.5-58.0 months. 7 patients died of tumor progression or recurrence, 1 died of pulmonary infection, and 1 died of the shunt obstruction. VPS associated complications included intracranial infection and the shunt obstruction. VPS associated intracranial infection was found in one (3.6%) patient. After antibiotic treatment, the infection was cured and a revision surgery was not needed. Obstruction of the shunt was found in one (3.6%) patient and a revision surgery was performed. Inappropriate location was found in one (3.6%) patient.
Clinical factors correlated with surgical outcome and survivals
Kaplan-Meier analysis of HFS and OS were shown in Figure 3A. The one-year and two-year HFS rate was both 88.7%. The one-year and two-year OS rate was both 66.7%. Patients’ age (>40/≤40), gender (Male/Female), tumor grade (WHO Ⅰ-Ⅱ/WHO Ⅲ-Ⅳ), hydrocephalus before tumor resection (yes/no), VPS before tumor resection (yes/no), tumor resection (yes/no), hydrocephalus after tumor resection (yes/no), VPS associated intracranial infection (yes/no) were recorded and analyzed. Parameters significantly correlated with OS were identified using the log-rank test and Cox’s regression model (table 3). Univariate analyses revealed that elder patient age, hydrocephalus before tumor resection and lower tumor grade were significantly correlated with longer OS (Figure 3B). Multivariate analysis revealed only lower tumor grade was an independent prognostic factor for longer OS (OR: 0.147, 95%CI: 0.030-0.714, P=0.017).
Case 24 (diffuse midline glioma)
A 24-year old female was admitted in our neurosurgical emergency, who complained with continuous vertigo and vomit for 1 week. Neurological examination revealed optic disc edema. CT revealed bilateral thalamic hypo-density lesion occupying the Foramen of Monroe with hydrocephalus (Fig. 4A). MR images revealed hydrocephalus caused by hypothalamic and bilateral thalamic lesions with long T1 and long T2 signals as well as partial enhancement (Fig. 4B-F). Bilateral Y-shaped VPS was performed to resolve hydrocephalus with programmable and anti-siphon shunt (Fig 4G). Then, stereotactic biopsy was performed to elucidate the pathology as diffuse midline glioma (Figure 4H, WHO IV, IDH wild-type) with H3K27M (+++), IDH1/2 wild-type, MGMT promoter methylation (-), and EGFR mutation and amplification (-). Immunohistochemical staining showed GFAP (++), Oligo-2 (+++), ATRX (+), P53 (++), and Ki-67 (10%). The patients underwent radiotherapy, concurrent and adjuvant temozolomide chemotherapy. MR images revealed tumor progression and spread 6 months after shunt (Fig 4I-M), and the patient died 2 months later.
Case 26 (diffuse midline glioma)
A 17-year old female was admitted in our emergency, who complained with continuous vertigo and vomit for 2 weeks. Neurological examination revealed optic disc edema. CT revealed a lesion with bilateral thalamic hypodensity occupying the Foramen of Monro with hydrocephalus (Fig. 5A-B). Bilateral Y-shaped VPS was performed to resolve hydrocephalus with programmable and anti-siphon shunt (Fig 5C). Post-VPS MR images revealed hypothalamic and bilateral thalamic lesions with long T1 and long T2 signals as well as mild enhancement (Fig. 5D-K). Then, stereotactic biopsy was performed to elucidate the pathology as diffuse midline glioma (WHO IV, IDH wild-type) with H3K27M (+++) and MGMT promoter methylation (-). Immunohistochemical staining showed GFAP (+++), Oligo-2 (+), ATRX (+++), P53 (+++), and Ki-67 (2%). The patients underwent radiotherapy, concurrent and adjuvant timozolomide chemotherapy. 15 months after shunt, MR images revealed tumor shrinkage (Fig 5L-Q).
Case 21 (post-operative multiloculated hydrocephalus)
A 22-year-old female was admitted in our hospital with the radiological diagnosis of central neurocytoma in the bilateral ventricles and obstructive hydrocephalus. She complained of intermittent headache for 1 year, intensified headache with nausea and vomiting for 2 months. Neurological examination revealed optic disc edema. CT revealed a lesion with mixed density in the bilateral ventricles involving the Foramen of Monro (Fig. 6A). MR images revealed a lesion with mixed T1 and T2 signals as well as heterogeneous enhancement (Fig. 6B-D).
The patient underwent a right frontal trans-callosal approach for total removal of the tumor. During the operation, the tumor was found to be a purple-red soft mass in the bilateral ventricles. Postoperative pathology confirmed the diagnosis of central neurocytoma (WHO grade II). One week after surgery, the patient had intermittent fever, and the CSF analysis demonstrated intracranial infection. Combined Vancomycin and meropenem plus lumbar cistern drainage were used for treatment. About 5 weeks after the surgery, the patient still had cognitive difficulties, and an emergency CT scan revealed the right entrapped temporal horn (Fig. 6E). The patient underwent puncture and drainage of the trigone of the right lateral ventricle (Fig. 6F). However, about 9 weeks after the primary surgery, the MR scan showed the formation of an abscess in the surgical field (Fig. 6G). The abscess disappear after puncture and external drainage guided by the ultrasound (Fig. 6H). About 11 weeks after the primary surgery, the patient still had cognitive difficulties, and her left limbs were still weak. An emergency CT scan revealed bilateral hydrocephalus with right entrapped temporal horn (Fig. 6I-J). The patient underwent Y-shaped VPS with triple ventricular catheters and low-pressure anti-siphon shunt (Fig. 6K-L). After shunt, the patient was discharged for the rehabilitation therapy. The patient recovered well 1 year later (Fig. 6M-N).
Case 20 (post-operative extra-ventricular hydrocephalus)
A 19-year-old male was admitted to our hospital with a mass in the pineal region and obstructive hydrocephalus. He complained of intermittent headache for half a year. Neurological examination revealed Parinaud syndrome. CT revealed a lesion with mixed density and calcification (Fig. 7A). MR images revealed a lesion with iso-T1 long-T2 signals and homogeneous enhancement (Fig. 7B-D).
The patient underwent a right frontal trans-callosal approach for total removal of the tumor (Fig. 7E-G). The tumor was found to be a grey-red mass with less defined borders in the pineal region. Postoperative pathology revealed the diagnosis of pineal parenchymal tumor of intermediate differentiation (WHO grade III). The patient was discharged 13 days after surgery. Ten days later, the patient was re-admitted to our hospital for sudden headache, nausea and vomiting. An emergency CT scan revealed the right fronto-tempo-parietal subdural effusion (Fig. 7H), and an emergency drainage was performed (Fig. 7I). Nine days after drainage, the patient still had intermittent headache and cognitive difficulties, CT scan revealed unchanged subdural effusion with hydrocephalus (Fig. 7J). The patient underwent bilateral Y-shaped VPS with programmable and anti-siphon shunt, one draining the right subdural effusion and the other one draining the left ventricular frontal horn (Fig. 7K). Five days later, the patient had a fever, and the CSF analysis revealed increased WBC count. Combined vancomycin and meropenem were used and the patient was discharged for radiotherapy with improved KPS. At the last follow-up 8 months after the primary surgery, the patient had been back to job (Fig. 7L-P).
Case 17 (sequential Y-shaped hydrocephalus)
A 52-year-old Male was admitted in our hospital for headache and vomiting. Radiological images revealed a mass in the third ventricle with left obstructive hydrocephalus (Fig 8A-D). Considering the risk of tumor resection, the patient refused tumor resection and received left frontal horn VPS to resolve hydrocephalus (Fig 8E). 6 months later, the patient was re-admitted in our hospital for headache and incontinence. MR and CT scan revealed right obstructive hydrocephalus (Fig 8F-I). To resolve the hydrocephalus, right frontal ventricular tip was added to the original shunt by a Y-shaped connector. And the bilateral hydrocephalus was well resolved (Fig 8J). This is an illustrative case with sequential bilateral VPS with Y-shaped connector.