Thermosensitive determination of obstructed sites in ventriculoperitoneal shunts

1985 ◽  
Vol 62 (3) ◽  
pp. 363-366 ◽  
Author(s):  
Yasuhiro Chiba ◽  
Yusuke Ishiwata ◽  
Noriyuki Suzuki ◽  
Masato Muramoto ◽  
Yumiko Kunimi
Keyword(s):  
Experimental Model ◽  
Ventricular Catheter ◽  
Simple Method ◽  
Content Type ◽  
Ventriculoperitoneal Shunts ◽  
Upward Deflection ◽  
Small Disc ◽  
Fine Print

✓ A simple method is described for checking the patency of ventriculoperitoneal shunts by using a pair of small disc thermistors. With this technique, shunt patency is shown by a downward deflection of the recording trace, blockage of the ventricular catheter is indicated by a flat-line recording, and obstruction of the distal end of the abdominal catheter is demonstrated by an upward deflection. These observations were confirmed in a study of 32 hydrocephalic patients with obstructed shunts who subsequently underwent shuntography and operation. An experimental model was also devised to study the mechanism of the recording changes.

Thermosensitive determination of patency in lumboperitoneal shunts

1989 ◽  
Vol 70 (1) ◽  
pp. 143-145 ◽  
Author(s):  
Yusuke Ishiwata ◽  
Yasuhiro Chiba ◽  
Toshinori Yamashita ◽  
Gakuji Gondo ◽  
Kaoru Ide ◽  
...  
Keyword(s):  
Cerebrospinal Fluid ◽  
Normal Pressure ◽  
Cerebrospinal Fluid Shunt ◽  
Surface Cooling ◽  
Content Type ◽  
Ventriculoperitoneal Shunts ◽  
Upward Deflection ◽  
Shunt Tubing ◽  
Fine Print

✓ Surface cooling and thermistor recording over shunt tubing was used in 23 studies of cerebrospinal fluid shunt patency in 19 patients with lumboperitoneal shunts and normal-pressure hydrocephalus. Shunt patency was shown by downward reflection of the recording trace similar to that obtained for ventriculoperitoneal shunts. Obstruction was demonstrated by a flat-line recording or an upward deflection.

Thermosensitive determination of CSF shunt patency with a pair of small disc thermistors

1980 ◽  
Vol 52 (5) ◽  
pp. 700-704 ◽  
Author(s):  
Yasuhiro Chiba ◽  
Kenji Yuda
Keyword(s):  
Normal Pressure ◽  
Adult Patients ◽  
Csf Shunt ◽  
Simple Method ◽  
Content Type ◽  
Temperature Changes ◽  
Small Disc ◽  
Clinical Pictures ◽  
Shunt Obstruction

✓ A simple method is presented for detecting the patency of ventriculoperitoneal shunts with a pair of small disc thermistors. In an experimental model, the equipment detected definite temperature changes along the shunt tube. The extent of the temperature difference was proportional to the flow velocities, ranging from 5 to 60 ml/hr (120 to 1440 ml/24 hrs). A clinical study consisted of 26 trials in 23 hydrocephalic children and 10 trials in nine adult patients with normal-pressure hydrocephalus. Three of the 26 trials in the children were unsuccessful because of patient irritability and lack of cooperation. All trials for adult patients were successful. In all 25 patients, whose clinical pictures suggested functioning shunt, accurate confirmation of shunt patency was obtained. In six patients whose clinical pictures suggested questionable shunt function, this method revealed that all shunts were patent, and computerized tomography and follow-up clinical data supported this finding. In two patients whose clinical pictures suggested shunt malfunction, there was no indicator deflection, and shunt obstruction was proved at operation. This method is effective in checking shunt function, is simple, and may be repeated at frequent intervals.

A simple method for distal catheter lengthening of ventriculoperitoneal shunts

1992 ◽  
Vol 77 (5) ◽  
pp. 810-811 ◽  
Author(s):  
Todd M. Goldenberg ◽  
Michael B. Pritz
Keyword(s):  
Simple Technique ◽  
Simple Method ◽  
Distal Catheter ◽  
Content Type ◽  
Ventriculoperitoneal Shunts ◽  
Fine Print

✓ A simple technique to lengthen the distal catheter of ventriculoperitoneal shunts is described. This method, which utilizes a guidewire, has been successful in elective shunt revisions in eight children.

The effects of dexamethasone on bone fusion in an experimental model of posterolateral lumbar spinal arthrodesis

2001 ◽  
Vol 94 (1) ◽  
pp. 76-81 ◽  
Author(s):  
Paul D. Sawin ◽  
Curtis A. Dickman ◽  
Neil R. Crawford ◽  
M. Stephen Melton ◽  
William D. Bichard ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Bone Graft ◽  
Spinal Fusion ◽  
Experimental Model ◽  
Content Type ◽  
Bone Fusion ◽  
Group 12 ◽  
Spinal Arthrodesis ◽  
Lumbar Spinal ◽  
Fine Print

Object. The use of corticosteroid agents during the healing phase after spinal arthrodesis remains controversial. Although anecdotal opinion suggests that corticosteroids may inhibit bone fusion, such an effect has not been substantiated in clinical trials or laboratory investigations. This study was undertaken to delineate the effect of exogenous corticosteroid administration on bone graft incorporation in an experimental model of posterolateral lumbar fusion. Methods. An established, well-validated model of lumbar intertransverse process spinal fusion in the rabbit was used. Twenty-four adult New Zealand white rabbits underwent L5–6 bilateral posterolateral spinal fusion in which autogenous iliac crest bone graft was used. After surgery, the animals were randomized into two treatment groups: a control group (12 rabbits) that received intramuscular injections of normal saline twice daily and a dexamethasone group (12 rabbits) that received intramuscular dexamethasone (0.05 mg/kg) twice daily. After 42 days, the animals were killed and the integrity of the spinal fusions was assessed by radiography, manual palpation, and biomechanical testing. In seven (58%) of the 12 control rabbits, solid posterolateral fusion was achieved. In no dexamethasone-treated rabbits was successful fusion achieved (p = 0.003). Tensile strength and stiffness of excised spinal segments were significantly lower in dexamethasone-treated animals than in control animals (tensile strength 91.4 ± 30.6 N and 145.3 ± 48.2, respectively, p = 0.004; stiffness 31.4 ± 11.6 and 45.0 ± 15.2 N/mm, respectively, p = 0.02). Conclusions. The corticosteroid agent dexamethasone inhibited bone graft incorporation in a rabbit model of single-level posterolateral lumbar spinal fusion, inducing a significantly higher rate of nonunion, compared with that in saline-treated control animals.

A clinical comparison of subdural screw pressure measurements with ventricular pressure

1983 ◽  
Vol 58 (1) ◽  
pp. 45-50 ◽  
Author(s):  
A. David Mendelow ◽  
John O. Rowan ◽  
Lilian Murray ◽  
Audrey E. Kerr
Keyword(s):  
Head Injury ◽  
Intracranial Pressure ◽  
Severe Head Injury ◽  
Fluid Pressure ◽  
Ventricular Catheter ◽  
Pressure Measurements ◽  
Content Type ◽  
Single Lumen ◽  
Ventricular Fluid Pressure ◽  
Fine Print

✓ Simultaneous recordings of intracranial pressure (ICP) from a single-lumen subdural screw and a ventricular catheter were compared in 10 patients with severe head injury. Forty-one percent of the readings corresponded within the same 10 mm Hg ranges, while 13% of the screw pressure measurements were higher and 46% were lower than the associated ventricular catheter measurements. In 10 other patients, also with severe head injury, pressure measurements obtained with the Leeds-type screw were similarly compared with ventricular fluid pressure. Fifty-eight percent of the dual pressure readings corresponded, while 15% of the screw measurements were higher and 27% were lower than the ventricular fluid pressure, within 10-mm Hg ranges. It is concluded that subdural screws may give unreliable results, particularly by underestimating the occurrence of high ICP.

Bilateral open-door cervical expansive laminoplasty with hydroxyapatite spacers and titanium screws

2002 ◽  
Vol 96 (1) ◽  
pp. 22-28 ◽  
Author(s):  
Masakazu Takayasu ◽  
Teruhide Takagi ◽  
Toshihisa Nishizawa ◽  
Koji Osuka ◽  
Takehiko Nakajima ◽  
...  
Keyword(s):  
Screw Fixation ◽  
Cervical Spinal Cord ◽  
Intraoperative Complications ◽  
Fixation Strength ◽  
Open Door ◽  
Quick Method ◽  
Simple Method ◽  
Content Type ◽  
Titanium Screws ◽  
Fine Print

Object. The authors report a simple method for bilateral open-door cervical expansive laminoplasty in which hydroxyapatite (HA) spacers are secured by titanium screws. A biomechanical study was also conducted to confirm the strength of the screw fixation. Methods. A unilateral posterior approach was used to allow preservation of the posterior supporting elements (the posterior tension band) until the laminae were cut at the base. A bilateral open-door expansive laminotomy was then performed in standard fashion. Appropriate-sized HA spacers were selected, held with a specially designed holder, and placed between the split laminae. The screw holes were made in the laminae along the direction of the screw holes in the spacer, and two screws were inserted ventrolaterally to the laminae, resulting in instantaneous fixation. This procedure was performed in 15 patients; clinical results were successful, and there were no significant intraoperative complications. Follow-up radiological studies revealed no evidence of displacement of the spacers or screw backout. The screw artifacts observed on magnetic resonance imaging were minimal, allowing evaluation of the cervical spinal cord. The sagittal alignment of the cervical spine was well preserved. In the biomechanical studies the authors found that the screw fixation was of satisfactory strength, compared with other methods of fixation. Conclusions. Bilateral open-door cervical expansive laminoplasty in which HA spacers are secured by titanium screws is a simple and quick method that yields sufficient fixation strength.

Contribution of CSF and vascular factors to elevation of ICP in severely head-injured patients

1987 ◽  
Vol 66 (6) ◽  
pp. 883-890 ◽  
Author(s):  
Anthony Marmarou ◽  
Angelo L. Maset ◽  
John D. Ward ◽  
Sung Choi ◽  
Danny Brooks ◽  
...  
Keyword(s):  
Severe Head Injury ◽  
Ventricular Catheter ◽  
Outflow Resistance ◽  
Content Type ◽  
Relative Contribution ◽  
Temporal Course ◽  
Head Injured ◽  
Predominant Factor ◽  
Injured Patients ◽  
Fine Print

✓ The authors studied the relative contribution of cerebrospinal fluid (CSF) and vascular parameters to the level of intracranial pressure (ICP) in 34 severely head-injured patients with a Glasgow Coma Scale score of less than 8. This was accomplished by first characterizing the temporal course of CSF formation and outflow resistance during the 5-day period postinjury. The CSF formation and outflow resistance were obtained from pressure responses to bolus addition and removal of fluid from an indwelling ventricular catheter. The vascular contribution to the level of ICP was assessed by withdrawing fluid at its rate of formation and observing the resultant change in equilibrium ICP level. It was found that, with the exception of patients with subarachnoid hemorrhage, CSF parameters accounted for approximately one-third of the ICP rise after severe head injury, and that a vascular mechanism may be the predominant factor in elevation of ICP.

Subcutaneous reaction to silicone in ventriculoperitoneal shunts

1974 ◽  
Vol 41 (3) ◽  
pp. 367-371 ◽  
Author(s):  
Oscar Sugar ◽  
Orville T. Bailey
Keyword(s):  
Cerebrospinal Fluid ◽  
Connective Tissue ◽  
Fibrous Connective Tissue ◽  
Subcutaneous Implantation ◽  
Content Type ◽  
Ventriculoperitoneal Shunts ◽  
Silicone Tubing ◽  
Connective Tissue Sheath ◽  
Fine Print

✓Silicone tubing (Silastic) used for ventriculoperitoneal shunts induces a fibrous connective tissue sheath around the tubing in children and adults. Two children examined 8 and 3 years after subcutaneous implantation showed a complete tube of dense fibrous connective tissue around the silicone tubing. The reaction was entirely quiescent. These tubes of connective tissue were apparently capable of conveying cerebrospinal fluid for some months after the silicone tubing was disconnected from the pump or pulled out of the abdomen.

Evaluation of the central canal of the spinal cord in experimentally induced hydrocephalus

1978 ◽  
Vol 48 (6) ◽  
pp. 970-974 ◽  
Author(s):  
A. Everette James ◽  
William J. Flor ◽  
Gary R. Novak ◽  
Ernst-Peter Strecker ◽  
Barry Burns
Keyword(s):  
Spinal Cord ◽  
Cerebrospinal Fluid ◽  
Experimental Model ◽  
Alternative Pathway ◽  
Central Canal ◽  
Communicating Hydrocephalus ◽  
Csf Flow ◽  
Content Type ◽  
Histological Appearance ◽  
Fine Print

✓ The central canal of the spinal cord has been proposed as a significant compensatory alternative pathway of cerebrospinal fluid (CSF) flow in hydrocephalus. Ten dogs were made hydrocephalic by a relatively atraumatic experimental model that simulates the human circumstance of chronic communicating hydrocephalus. The central canal was studied by histopathology and compared with 10 normal control dogs. In both groups the central canal of the spinal cord was normal in size, configuration, and histological appearance. In this experimental model dilatation of the canal and increased movement of CSF does not appear to be a compensatory alternative pathway.

Management of proximal shunt obstruction

1988 ◽  
Vol 68 (5) ◽  
pp. 817-819 ◽  
Author(s):  
Charles C. Duncan
Keyword(s):  
Cerebrospinal Fluid ◽  
Fluid Flow ◽  
Intracranial Pressure ◽  
Signs And Symptoms ◽  
Ventricular Catheter ◽  
Shunt Failure ◽  
Content Type ◽  
Cerebrospinal Fluid Flow ◽  
Shunt Obstruction ◽  
Fine Print

✓ Proximal shunt obstruction or obstruction of the ventricular catheter may present with signs and symptoms of shunt failure with either no cerebrospinal fluid flow or a falsely low intracranial pressure (ICP) upon shunt tap. The author reports a technique for lowering the ICP and for measuring the pressure in patients with such obstruction by cannulation of the reservoir and ventricular catheter to penetrate into the ventricle with a 3½-in. No. 22 spinal needle. The findings in 20 cases in which this approach was utilized are summarized.

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