The intracranial pressure-monitoring cup catheter: technical note

The author describes a simple catheter designed for use in the measurement of intracranial pressure, especially during the initial stage following craniotomy. The device has been studied in experimental animals, and has been used in 40 neurosurgical patients for periods up to 15 days.     

A simple suture shuttle in rotator cuff repairs: a technical note

In rotator cuff repairs, it is often necessary to pass 2 tails of 2 sutures through 1 transosseous hole to maximize the number of sutures per hole. We report on a simple technique with a double-loop suture thread that allows the passing of more than 1 suture limb through the same hole. This simple device, the simple suture shuttle, used in cuff repairs in combination with the modified Mason-Allen suture technique, significantly reduces the difficulty of passing more than 1 suture tail through a single bone tunnel. By reducing the number of bone tunnels, the weakening of a bone that might not be very strong is kept to a minimum. The Simple Suture Shuttle can also be used to pass more sutures through a given number of transosseous holes.     

Intracranial pressure monitoring by a subdurally placed silicone catheter: technical note

A silicone catheter manufactured originally for ventricular fluid drainage was used for continuous monitoring of intracranial pressure. It can be placed under the dura mater immediately before replacing the craniotomy flap or by introduction through an ordinary burr hole. Pressure is monitored isovolumetrically by connecting the catheter to a pressure transducer mounted at the bedside. This technique has been used in 34 neurosurgical patients for periods of up to 12 days without any untoward effects. This monitoring system by a subdurally placed silicone catheter is simple, safe, inexpensive, and acceptably reliable. It has a place in clinical practice, particularly when the lateral ventricle cannot be tapped because of its deviation or collapse.     

Ventriculoatrial shunt distal catheter placement using transesophageal echocardiography: technical note.

Accurate placement of the distal end of a ventriculoatrial shunt at the cavo-atrial junction is important for long-term shunt function as well as for avoiding cardiac arrhythmias, thrombus formation, and damage to myocardial tissue. Standard methods of intraoperative localization, including chest x-ray, pressure measurements, and electrocardiogram recording, can be inaccurate. By using intraoperative transesophageal echocardiography, the distal end of the catheter can be localized to the cavo-atrial junction.     

Arthroscopic suture anchor repair of posterior root attachment injury in medial meniscus: technical note

A root attachment injury (root tear) of the meniscus can abolish the ability of the meniscus to bear hoop stress and predispose to increase articular contact stress which contribute to femorotibial degenerative changes. A pull out suture technique to repair the root tear has been described, but the procedure making the tibial tunnel may be difficult and troublesome. This article describes a repair technique using a suture anchor and posterior trans-septal portal.     

Use of small suture anchors in cervical laminoplasty to maintain canal expansion: a technical note

OBJECTIVE: Open door laminoplasty is a commonly performed procedure for the treatment of cervical spine pathology. One complication of this procedure is closure of the hinge and subsequent restenosis. A simple and effective method of using suture anchors to stabilize posterior elements has been previously described. The aim of this paper is to describe our experience using 2.0-mm suture anchors to maintain canal expansion. METHODS: Results of 42-consecutive patients who were treated with a modified cervical open-door laminoplasty were reviewed. The modification involves the use of original Hirabayashi technique, but augmenting the canal expansion with 2.0-mm suture anchors at C3, C5, and C7 levels. Additionally, nonabsorbable sutures are placed at C4 and C6 levels as described by Hirabayashi. The technical issues and short-term radiographic outcomes were evaluated. RESULTS: None of the 42 patients who had the door secured with 2.0-mm suture anchors had closure of the hinge. Additionally, the suture anchors maintained their position without loosening or "pull-outs" on postoperative follow-up radiographs. There were 3 short-term complications: 1 was a small dural-tear which was repaired intraoperatively without further sequelae, and the other 2 were both epidural hematomas that required emergent return to the operating room for evacuation. All 3 patients had an uneventful recovery without a new neurologic deficit. CONCLUSIONS: This paper reviews a simple and effective method for maintaining canal expansion in open-door laminoplasty. Because of its technical simplicity, 2.0-mm suture anchors may be a safer alternative than other devices currently popular for this purpose.     

Cervical hemilaminoplasty: technical note

Ten patients with cervical spinal schwannomas were operated using a new posterior approach, termed cervical hemilaminoplasty. A thread wire saw (T-saw) was used to cut the lamina at the center of the spinous process and at the unilateral pars interarticularis on the affected side. The unilateral lamina, the inferior articular process, and half of the spinous process were resected as a single mass. After tumor excision, the resected lamina was restored to the original site and fixed. Fusion technique was not required. The mean number of resected and restored lamina was 1.5. No instability of the cervical spine was detected using flexion/extension x-ray photography. Although worsening of radicular motor function was observed in 2 cases, the weakness was not permanent and both cases showed full recovery. Postoperative magnetic resonance imaging was performed in 7 of the 10 cases and showed no recurrences. Cervical hemilaminoplasty is a useful posterior approach method for spinal tumors and especially dumbbell-type tumors. This method provides wide exposure of the foramen and of the inside of the canal. Furthermore, it allows reconstruction of the posterior element of the spinal canal and results in good stability.     

Cranioplasty technical note

Summary A modification of Galicich and Hovind's method of cranioplasty is described. The prosthesis is not made on a side-table in the operation theatre. Steel wire mesh is fastened to the edge of the bone defect with stainless wires passed through drill holes. Acrylic mixture is then poured over the mesh and is cooled with saline. The technique has its main advantage in simplicity, and the result is cosmetically and functionally satisfactory.     

Cervical hemilaminectomy reconstruction: technical note

STUDY DESIGN: A technique for posterior cervical hemilaminectomy reconstruction is described. OBJECTIVE: To describe a technique for reconstruction of cervical hemilaminae in an adult that resulted in osseous fusion and to suggest modifications for use in children. SUMMARY OF BACKGROUND DATA: Although uncommon, cervical hemilaminectomy can result in spine deformity. Re-establishment of the osseous and ligamentous structures should minimize this problem. METHOD: After excision of an intraspinal neurenteric cyst, removed cervical hemilaminae at C2 and C3 were reconstructed with metal plates, and posterior ligaments were reapproximated with suture. RESULTS: Radiologic evidence of osseous fusion was present at 1 year after surgery. CONCLUSIONS: The advantages of this technique are restoration of normal anatomy, technical ease, and simplicity. A modification of this technique in children by using absorbable rather than metal plates should allow for normal spine growth.     

Ligament-sparing lumbar microdiscectomy: technical note

Background

The prevention or inhibition of postoperative adhesions is a significant goal for successful lumbar discectomy, not only to reduce the probable risk of recurrent radiculopathy, but also to improve the likelihood of success of re-operation.

Methods

We describe a new technique for sparing the ligamentum flavum in lumbar microdiscectomy. The superficial layer of the ligament is removed by horizontal splitting. Additional horizontal splitting of the ligament yields a paper-thin deep layer. Lateral vertical splitting and retraction is then carried out to provide a sufficient operative window. The split ligament returns to its original position after releasing the retraction, thereby closing the operative window.

Results

This method could preserve a layer of the ligamentum flavum to act as a physical barrier, which in turn greatly restricts the peridural fibrosis.

Conclusions

This ligament-sparing technique enables surgeons to preserve the original anatomic plane and to reduce the extent of postoperative adhesion.     

Cerebrovascular biomodelling: a technical note

BACKGROUND: Recently computed tomographic angiography (CTA) and MR angiography (MRA) have been used to image cerebrovascular structures. Although CTA and MRA are accurate and sensitive imaging modalities, limitations have been identified in relation to image interpretation. Stereolithographic (SL) biomodelling is a new technology that allows three-dimensional (3D) CT and MR data to be used to accurately manufacture solid plastic replicas of anatomical structures. A prospective trial of SL biomodelling in cerebrovascular surgery has been performed to investigate the feasibility and clinical utility of this new display medium. METHODS: Fifteen patients with cerebral aneurysms and 1 patient with a cerebral arteriovenous malformation (AVM) were selected. 3D CT and/or MR angiograms were acquired and 19 solid anatomical biomodels manufactured using the rapid prototyping technology of stereolithography. The biomodels were used for patient education, diagnosis, operative planning and surgical navigation. RESULTS: The biomodels replicated the CTA and MRA source data. The accuracy of one biomodel was verified by comparison with a post mortem specimen, which corresponded exactly in the x and y planes but differed by 2 mm in the z plane. The ability to closely study an overview of complex cerebrovascular anatomy from any perspective on a solid biomodel was reported to enhance the surgeon's understanding, particularly when conventional images were equivocal. Cerebrovascular biomodels were found to be useful when positioning the patient's head for surgery, for selecting the best aneurysm clip and for the simulation of clipping. Patient informed consent was anecdotally improved. Disadvantages of the technology were the cost and manufacturing time. CONCLUSIONS: Cerebrovascular biomodelling may have utility in complex cases or when the standard imaging is felt to be equivocal.