The authors report their experience using preoperative chest radiography and intraoperative ultrasonography for percutaneous positioning of the distal end of the catheter when placing ventriculoatrial (VA) shunts in patients with hydrocephalus. The distal portion of VA shunt catheters were percutaneously placed into the internal jugular vein with the aid of intraoperative ultrasonography in 14 consecutive adults. In all cases, the technique was easy, there were no postoperative complications, and postoperative chest radiography demonstrated good positioning of the distal catheter tip. One patient presented with a shunt infection and needed a shunt replacement. The authors therefore conclude that percutaneous placement of a VA shunt under preoperative radiographic guidance and ultrasonographic monitoring is a safe, effective, and reliable technique that is simple to learn.
Accuracy of percutaneous placement of a ventriculoatrial shunt under ultrasonography guidance: a retrospective study at a single institution
Philippe Metellus, Wesley Hsu, Siddharth Kharkar, Sumit Kapoor, William Scott, and Daniele Rigamonti
Bilateral retinal hemorrhage after endoscopic third ventriculostomy: iatrogenic Terson syndrome
Eelco W. Hoving, Mehrnoush Rahmani, Leonie I. Los, and Victor W. Renardel de Lavalette
A serious ophthalmological complication of an endoscopic third ventriculostomy that created an iatrogenic Terson syndrome is described. A patient with an obstructive hydrocephalus was treated endoscopically, but due to the inadvertent use of a pressure bag during rinsing, in combination with a blocked outflow channel, a steep rise in intracranial pressure occurred. Postoperatively the patient experienced disturbed vision caused by bilateral retinal hemorrhages, and an iatrogenic Terson syndrome was diagnosed. The pathogenesis of Terson syndrome is discussed based on this illustrative case.
Burying shunts in bone cavities to protect delicate scalp
Michael Ellis, Merdas Al-Otibi, Peter Bray, and Mark Bernstein
The authors describe a simple technique for protecting at-risk scalp overlying CSF shunt hardware. Patients with brain tumors commonly undergo radiation therapy and CSF diversion. Chronic radiation-induced changes in the skin can predispose patients to skin breakdown over the prominent shunt reservoir, which may lead to subsequent contamination of the shunt hardware. The technique described reduces the risk of hardware contamination while obviating the need for revision of the entire shunt system. By reducing the profile of the CSF shunt reservoir, this technique also reduces the risk of future skin ulceration.
Is the distance between mammillary bodies predictive of a thickened third ventricle floor?
Corrado Iaccarino, Enrico Tedeschi, Armando Rapanà, Ilario Massarelli, Giuseppe Belfiore, Mario Quarantelli, and Alfredo Bellotti
The aim of this study was to correlate intraoperative endoscopic third ventriculostomy (ETV) findings in hydrocephalic patients with the MR imaging appearance of the mammillary bodies (MBs), the fundamental anatomical landmarks of the third ventricle floor (TVF) region.
The authors reviewed brain MR images and intraoperative ETV records in 23 patients with hydrocephalus as well as MR imaging data from 120 randomized control volunteers of various ages to define the normal intermammillary distance (IMD).
In control volunteers, no measurable IMD (“kissing” configuration) was observed in 91 (85%) of 107 cases, and there was mild MB splitting (mean ± standard deviation, 0.18 ± 0.12 cm) in only 16 cases with age-related cerebral atrophy. Among the 21 patients with complete MR imaging and ETV data sets, 12 ETV procedures were hindered by anatomical anomalies such as a thickened TVF or an “upward ballooning” phenomenon. On preoperative MR imaging in these 12 patients, there was an increased IMD (0.55 ± 0.41 cm) compared with that in the remaining 9 patients (0.27 ± 0.25 cm) who had a normal thin TVF during ETV and in the control group (0.03 ± 0.08 cm). Magnetic resonance imaging and ETV data concordantly displayed nonsplit MBs in 6 of 9 cases with a thin TVF and split MBs in 10 of 12 cases with a thick TVF.
The normal configuration of MBs is no measurable IMD, with mild splitting occurring in patients with age-related brain atrophy. In hydrocephalic patients, a thickened TVF was present almost exclusively with an increased IMD on preoperative MR imaging and separated MBs on endoscopic viewing. Large retrospective series are needed to confirm that a preoperative increased IMD is predictive of a thickened TVF during ETV.
Noninvasive biomarkers in normal pressure hydrocephalus: evidence for the role of neuroimaging
Andrew Tarnaris, Neil D. Kitchen, and Laurence D. Watkins
Normal pressure hydrocephalus (NPH) represents a treatable form of dementia. Recent estimates of the incidence of this condition are in the region of 5% of patients with dementia. The symptoms of NPH can vary among individuals and may be confused with those of patients with multi-infarct dementia, dementia of the Alzheimer type, or even Parkinson disease. Traditionally the diagnosis of NPH could only be confirmed postoperatively by a favorable outcome to surgical diversion of CSF. The object of this literature review was to examine the role of structural and functional imaging in providing biomarkers of favorable surgical outcome.
A Medline search was undertaken for the years 1980–2006, using the following terms: normal pressure hydrocephalus, adult hydrocephalus, chronic hydrocephalus, imaging, neuroimaging, imaging studies, outcomes, surgical outcomes, prognosis, prognostic value, sensitivity, specificity, positive predictive value, negative predictive value, and accuracy.
The query revealed 16 studies that correlated imaging with surgical outcomes offering accuracy results. Three studies fulfilled the statistical criteria of a biomarker. A dementia Alzheimer-type pattern on SPECT in patients with idiopathic NPH, the presence of CSF flow void on MR imaging, and the N-acetylaspartate/choline ratio in patients with the secondary form are able to predict surgical outcomes with high accuracy.
There is at present Level A evidence for using MR spectroscopy in patients with secondary NPH, and Level B evidence for using SPECT and phase-contrast MR imaging to select patients with idiopathic NPH for shunt placement. The studies, however, need to be repeated by other groups. The current work should act as a platform to design further studies with larger sample sizes.
The role of endoscopic third ventriculostomy in adult patients with hydrocephalus
Michael D. Jenkinson, Caroline Hayhurst, Mohammed Al-Jumaily, Jothy Kandasamy, Simon Clark, and Conor L. Mallucci
Endoscopic third ventriculostomy (ETV) is the treatment of choice for hydrocephalus, but the outcome is dependent on the cause of this disorder, and the procedure remains principally the preserve of pediatric neurosurgeons. The role of ETV in adult patients with hydrocephalus was therefore investigated.
One hundred ninety adult patients underwent ETV for hydrocephalus. Cases were defined as primary ETV (newly diagnosed, without a previously placed shunt) and secondary ETV (performed for shunt malfunctions due to infection or mechanical blockage). Causes of hydrocephalus included tumor, long-standing overt ventriculomegaly (LOVA), Chiari malformation Types I and II (CM-I and -II), aqueduct stenosis, spina bifida, and intraventricular hemorrhage (IVH). Successful ETV was defined as resolution of symptoms with shunt independence. Operative complications and ETV failure rate were investigated according to the causes of hydrocephalus and between the primary and secondary ETV groups.
In the primary group, ETV was successful in 107 (83%) of 129 patients, including those with tumors (52 of 66), LOVA (21 of 24), CM-I (11 of 11 cases), CM-II (8 of 9), aqueduct stenosis (8 of 9), and IVH (2 of 2). In the secondary group, ETV was successful in 41 (67%) of 61 patients and was equally successful in cases of mechanical shunt malfunction (35 of 52 patients) and infected shunt malfunction (6 of 9 patients). The median time to ETV failure was 1.7 months in the primary group and 0.5 months in the secondary group. The majority of ETV failures occurred within the first 3 months, and thereafter, the Kaplan-Meier survival curves plateaued. There were no procedure-related deaths, and complications were seen in only 5.8% of cases.
The success rate of ETVs in adults is comparable, if not better, than in children. In addition to the well-defined role of ETV in the treatment of hydrocephalus caused by tumors and aqueduct stenosis, ETV may also have a role in the management of CM-I, LOVA, persistent shunt infection, and IVH resistant to other CSF diversion procedures.
Negative-pressure hydrocephalus in the course of a complex postoperative intracranial pressure disturbance: illustrative case
Tomoya Suzuki, Shogo Kaku, Kostadin Karagiozov, and Yuichi Murayama
Negative-pressure hydrocephalus (NePH) is a rare clinical entity that presents on the background of ventriculomegaly with atypical symptoms. Its diagnosis is difficult, and some patients experience several shunt revisions until the proper solution is found.
The authors present a patient who developed acute deterioration due to iatrogenic NePH after surgery for a vertebral artery thrombosed giant aneurysm. The deterioration occurred after the insertion of a lumbar drain by which the authors intended to reduce a postoperative subcutaneous cerebrospinal fluid (CSF) collection. The drainage created an unexpected negative-pressure gradient in the CSF spaces, which resulted in NePH. Interventions, such as extraventricular drainage and blood patch, corrected the negative transmantle pressure and stabilized the patient’s condition.
Because the pathophysiology of NePH is theoretically considered to be caused by negative transmantle pressure, the intervention should be performed in order to deal with the coexistence of obstruction in the CSF pathways and a CSF leak. A blood patch would be an effective option in treating the CSF leak when the site of leakage is certain. This is the first case in which a blood patch was effectively applied in the treatment for NePH with a favorable outcome without any permanent CSF diversion.
Endoscopic third ventriculostomy for VP shunt malfunction during the third trimester of pregnancy: illustrative case
Ahmad K. Alhaj, Tariq Al-Saadi, Marie-Noëlle Hébert-Blouin, Kevin Petrecca, and Roy W. R. Dudley
Endoscopic third ventriculostomy (ETV) is a successful procedure for treating noncommunicating hydrocephalus as an alternative to initial ventriculoperitoneal (VP) shunt placement and as a salvage procedure when a VP shunt fails. Physiological changes of pregnancy can lead to VP shunt failure and complicate the management of shunt malfunction, particularly in the third trimester.
The authors present a case in which an ETV was successfully used in the third trimester (31 weeks of gestation) of pregnancy for acute hydrocephalus due to VP shunt malfunction, and the patient went on to deliver a healthy baby at term; the patient remained well in the long-term follow-up. An English-language PubMed literature review revealed four cases of VP shunt failure successfully treated with an ETV in the first or second trimester but no such reports in the third trimester of pregnancy.
ETV appears to be a safe and effective alternative to VP shunt replacement in the late prenatal period of pregnancy.
Evidence for increased intraabdominal pressure as a cause of recurrent migration of the distal catheter of a ventriculoperitoneal shunt: illustrative case
Christopher Lee, Lucinda Chiu, Pawan Mathew, Gabrielle Luiselli, Charles Ogagan, Rrita Daci, Brittany Owusu-Adjei, Rona S. Carroll, and Mark D. Johnson
Placement of a ventriculoperitoneal (VP) shunt is an effective treatment for several disorders of cerebrospinal fluid flow. A rare complication involves postoperative migration of the distal catheter out of the intraperitoneal compartment and into the subcutaneous space. Several theories attempt to explain this phenomenon, but the mechanism remains unclear.
The authors report the case of a 37-year-old nonobese woman who underwent placement of a VP shunt for idiopathic intracranial hypertension. Postoperatively, the distal catheter of the VP shunt migrated into the subcutaneous space on three occasions despite the use of multiple surgical techniques, including open and laparoscopic methods of abdominal catheter placement. Notably, the patient repeatedly displayed radiographic evidence of chronic bowel distention consistent with increased intraperitoneal pressure.
In this case, the mechanism of catheter migration into the subcutaneous space did not appear to be caused by pulling of the catheter from above but rather by expulsion of the catheter from the peritoneum. Space in the subcutaneous tissues caused by open surgical placement of the catheter was permissive for this process. Patients with chronic increased intraabdominal pressure, such as that caused by bowel distention, obesity, or Valsalva maneuvers, may be at increased risk for distal catheter migration.
Subcutaneous emphysema of the neck after shunt surgery for hydrocephalus in a case of metastatic ovarian cancer: illustrative case
Smrithi Sathish, M. Manoranjitha Kumari, Shyama S. Prem, and Gopalakrishnan M. Sasidharan
A 46-year-old female, a patient with a relapsed carcinoma in her ovary, had undergone ventriculoperitoneal (VP) shunt surgery for obstructive hydrocephalus due to vermian metastasis. Two weeks after the shunt surgery, she complained of discomfort in the neck. There was subcutaneous emphysema along the shunt track without tenderness or signs of inflammation. She was afebrile, and her vital parameters were stable.
The authors ruled out pneumothorax and airway trauma as potential sources of emphysema. They tapped the shunt chamber and detected gram-negative bacilli. Ascitic fluid culture grew gas-forming Escherichia coli.
Although some amount of air can get trapped in the subcutaneous plane during the tunneling procedure of a VP shunt tube insertion, the reappearance of a new, large column of air along the shunt track can be an ominous sign of shunt infection. The shunt became contaminated by bacteria of gut origin, which seeded the ascitic fluid, and a florid bacterial growth ascended up the shunt track, producing gas along the subcutaneous plane. Physicians should consider this rare etiology in their differential diagnoses of subcutaneous emphysema following VP shunt surgery.