Frederick A. Boop
Jean-François Hirsch and Christian Sainte-Rose
✓ A cortical incision performed with inflation of a balloon to create a channel has been used in an approach to deep lesions with minimal damage to cerebral tissue. The balloon is slipped over a blunt needle and, once in place, is inflated through the needle. Postoperative sealing of the incision with fibrin glue avoids the subdural collection of cerebrospinal fluid such as is sometimes observed when the ventricle is opened during surgery.
Christian Sainte-Rose, Michael D. Hooven, and Jean-François Hirsch
✓ To date, most patients suffering from hydrocephalus have been treated by insertion of differential-pressure valves that have fairly constant resistance. Since intracranial pressure (ICP) is a variable parameter (depending on such factors as patient's position and rapid eye movement sleep) and since cerebrospinal fluid (CSF) secretion is almost constant, it may be assumed that some shunt complications are related to too much or too little CSF drainage. The authors suggest a new approach to treating hydrocephalus, the aim of which is to provide CSF drainage at or below the CSF secretion rate within a physiological ICP range. This concept has led the authors to develop a three-stage valve system. The first stage consists of a medium-pressure low-resistance valve that operates as a conventional differential-pressure valve until the flow through the shunt reaches a mean value of 20 ml/hr. A second stage consists of a variable-resistance flow regulator that maintains flow between 20 and 30 ml/hr at differential pressures of 80 to 350 mm H2O. The third stage is a safety device that operates at differential pressures above 350 mm H2O (inducing a rapid increase in CSF flow rate) and therefore prevents hyper-elevated ICP. An in vitro study is described that demonstrates the capability of this system to maintain flow rates close to CSF production under a range of pressures similar to those observed under various human physiological and postural conditions. Promising clinical results in 19 patients shunted with this valve are summarized.
Raphael Guzman, Arjun V. Pendharkar, Michel Zerah, and Christian Sainte-Rose
Endoscopic third ventriculostomy (ETV) has become the procedure of choice for treatment of obstructive hydrocephalus. While patient selection is the most critical factor in determining the success of an ETV procedure, the technical challenge lies in the proper site of fenestration and the successful creation of a patent stoma. Positioning of a single balloon catheter at the level or below the floor of the third ventricle to achieve an optimal ventriculostomy can at times be challenging. Here, the authors describe the use of a double-barrel balloon catheter (NeuroBalloon catheter), which facilitates positioning across, as well as dilation of, the floor of the third ventricle. The surgical technique and nuances of using the NeuroBalloon catheter and the experience in more than 1000 cases are described. The occurrence of vascular injury was less than 0.1%, and the risk of balloon rupture was less than 2%. The authors found that the placement and deployment of this balloon catheter facilitate the creation of an adequate ventriculostomy in a few simple steps.
Dominique Renier, Christian Sainte-Rose, Daniel Marchac, and Jean-François Hirsch
✓ In this study, intracranial pressure (ICP) was recorded with an epidural ensor for periods of 12 to 24 hours in 92 cases of craniosynostosis. Pre- and postoperative recordings were performed in 23 patients, and 55 children underwent preoperative psychometric testing. The ICP was found to be normal in one-third of the cases, was obviously elevated in one-third, and was borderline in one-third. Waves of increased ICP were recorded during rapid eye movement (REM) sleep. After surgery, ICP decreased progressively and returned to normal in several weeks. A significant statistical relationship was found between the patients' ICP and their mental level: the higher the ICP the lower the mental level. The regression curve of ICP as a function of age shows that ICP is maximal at the age of 6 years and decreases later. The significance of these results is discussed. The authors recommend that ICP be recorded in cases of craniosynostosis since it is of some help in deciding whether patients should undergo surgery.
Anne-Laure Boch, Éric Hermelin, Christian Sainte-Rose, and Spiros Sgouros
Object. The authors studied new and calcified shunt catheters to identify the prevalence of failures caused by aging materials in the shunt. Complications associated with these devices have various origins. Among late complications, fracture or migration of the system is related to the subcutaneous adhesion of the distal tubing in a growing child. A review of a cohort of 64 children who underwent shunt placement in 1980 with barium-impregnated distal catheters showed that 10 of these patients underwent reoperation for complications related to aging of the shunt material. This group represents 15% of the whole series and 30% of those children who were followed for more than 3 years. The true impact of aging of materials on shunt function is probably underestimated.
Methods. The authors performed physical, chemical, and mechanical analyses of the retrieved aged catheters and also of new catheters, resulting in the following findings: 1) calcifications were observed only on the external surface of the catheter, predominantly in its subcutaneous segment at the level of the neck and anterior chest wall; 2) calcifications contained particles of free silicon and barium sulfate, signifying fragmentation of the polymer; 3) the microstructure of the silicone polymer was modified: microfractures and alteration of the polymeric network were observed; 4) silanol groups were observed on the external surface of the catheter; and 5) the mechanical properties of the silicone rubber were degraded, and the aged catheters were more brittle than the new ones, with ruptures at elongations and fracture energy much lower than that seen in new catheters.
Furthermore, in vitro testing with a metastable solution of simulated body fluid demonstrated the critical impact of pH variations in liquid media and surface degradation of the catheters on the precipitation of hydroxylapatite crystals.
Conclusions. Although most shunt complications can be addressed by better patient management and surgical technique, late complications appear to be partly related to aging of the material. Distal tubing calcifications have been observed in barium-impregnated catheters. The industry recently responded to these observations by introducing plain silicone-coated shunt tubing; further evaluation will show what improvement can be expected.
Stéphanie Meuric, Raja Brauner, Christine Trivin, Jean-Claude Souberbielle, Michel Zerah, and Christian Sainte-Rose
This study was performed to optimize the management of craniopharyngiomas, particularly by identifying factors predicting weight changes to prevent obesity.
A series of 35 patients who had undergone surgery at a mean age of 7.4 ± 3.7 years (standard deviation [SD]) and had been followed up until 14.9 ± 5 years of age by the same endocrinologist were assigned to one of three groups according to their hypothalamic involvement: Group 1 (10 patients) had no involvement, Group 2 (eight patients) had compression without involvement, and Group 3 (17 patients) had severe involvement.
Abnormal height and/or weight evolution indicated the craniopharyngioma in only 17% of the patients, although these elements were present at diagnosis in 85%. Before surgery, 85% of the patients lacked growth hormone, 24% lacked thyroid-stimulating hormone, 15% lacked adrenocorticotropin hormone, and 12% lacked antidiuretic hormone. All had complete hypothalamic—pituitary deficiencies after surgery.
The body mass index (BMI) before surgery (mean SD 1.1 ± 1.6) was positively correlated with BMI 1 year after surgery (mean SD 3.1 ± 2), which correlated with the BMI at the last evaluation (mean SD 3.1 ± 1.9; p < 0.0001 for both). Before surgery, patients in Group 3 had a greater BMI than did Group 1 (p < 0.02). The BMI of Group 1 patients did not change, but those of Groups 2 and 3 patients increased during the 1st year after surgery (p < 0.02 and p = 0.0003, respectively), with no further change. The changes occurred mainly during the first 3 months after surgery in Group 1, during the first 6 months in Group 2, and throughout the year in Group 3.
The degree of hypothalamic involvement by the craniopharyngioma determines the presentation and predicts weight changes after surgery.
Mario Francesco Fraioli, Filiberto Contratti, and Chiara Fraioli
Darach William Crimmins, Alain Pierre-Kahn, Christian Sainte-Rose, and Michel Zerah
The authors sought to determine the natural history of and optimal treatment for suprasellar cysts (SSCs).
Three hundred forty-two patients harboring intracranial cysts presented to the authors’ neurosurgery unit between January 1986 and August 2004. The patients’ records were reviewed to assess symptomatology, results of imaging studies, and outcome according to mode of treatment.
Thirty-three patients (9.6%) were eligible for this study. Nine SSCs were diagnosed prenatally and 24 were identified postnatally (range 0 months–18.2 years, mean 5.6 years). The mean follow-up period was 66.8 ± 44.6 months (standard deviation). Seven cysts were left untreated, six (66%) detected before birth and one (4.5%) after birth. Of the 26 patients who required surgery, three were admitted elsewhere for complications of shunt surgery. A ventriculocystostomy (VC) was performed in all three of these patients, but the treatment failed in two. The primary treatment in the remaining 23 children was: open fenestration in two patients, VC in seven, ventriculocystocisternostomy (VCC) in 13, and cystoperitoneal (CP) shunt in one patient. Both open fenestration procedures were successful, as was the CP shunt insertion. The success rate of primary endoscopic surgery, although not statistically significant, was higher for VCCs (11 [85%] of 13 patients) than for VCs (four [57%] of seven patients). None of the patients’ preoperative endocrine disorders resolved postoperatively. The distribution of intellectual and developmental quotients paralleled the normal range. Intellectual performance was unrelated to patient-specific factors or to treatment modalities.
Most SSCs are of moderate size, are stable and asymptomatic, and have a favorable outcome. Treatment is required when the cyst evolves or the patient is symptomatic, but endocrine disturbances alone are not an indication for surgery. When hydrocephalus is present, endoscopic fenestration is the primary treatment of choice. The goal of the procedure should be to open the cyst into both the ventricles and the cisterns. Intellectual capability after treatment at outcome is not related to age at diagnosis, initial or final cyst size, presence or absence of hydrocephalus, or type of endoscopic treatment.