Pinning in pediatric neurosurgery: the modified rubber stopper technique

Comparison of the Efficacy of Sterile Silicone Studs Versus Lidocaine for the Attenuation of the Hemodynamic Response to Skull Pin Insertion: A Randomized Controlled Trial

BACKGROUND

Skull pin insertion causes hypertension and tachycardia that adversely affects cerebral hemodynamics. We compared the efficacy of sterile silicone studs (SS) and pin site infiltration with lidocaine in attenuation of the sympathetic response to skull pin insertion.

METHODS

Adult patients (N = 120) undergoing supratentorial craniotomy under general anesthesia were randomized to receive either medical-grade sterile SS or 2 mL of 2% plain lidocaine infiltration at each pin site. Hemodynamic (heart rate and mean arterial pressure) response to skull pin insertion at baseline and at 0, 1, 2, 3, and 5 minutes after skull pin insertion was compared. Requirement of rescue analgesia (fentanyl), complications such as pin-site bleeding, and surgeon satisfaction score were assessed.

RESULTS

Heart rate in the lidocaine group was significantly greater at 0, 1, 2, 3, and 5 minutes after pin insertion compared with the SS group (P < 0.05). Mean arterial pressure was also significantly higher in the lidocaine group at 0, 1, 2, and 3 minutes after pin insertion (P = 0.001, P = 0.01, P = 0.034, and P = 0.042) compared with the SS group. The number of patients requiring fentanyl [17/60 (28.3%) vs. 40/60 (66%), P = 0.001] was lower in the SS group. The incidence of pin site bleeding was also lower in the SS group, and surgeon satisfaction score was greater.

CONCLUSIONS

Sterile SS appear to be more effective than lidocaine infiltration in attenuating the hemodynamic response to skull pin insertion with minimal adverse effects. Further multicenter studies are necessary to conclusively establish the safety and efficacy of sterile SS.

Anatomical step-by-step dissection of common approaches to the third ventricle for trainees: surgical anatomy of the anterior transcortical and interhemispheric transcallosal approaches, surgical principles, and illustrative pediatric cases

PURPOSE

To create a high-quality, cadaver-based, operatively oriented resource documenting the anterior transcortical and interhemispheric transcallosal approaches as corridors to the third ventricle targeted towards neurosurgical trainees at all levels.

METHODS

Two formalin-fixed, latex-injected specimens were dissected under microscopic magnification and endoscopic-assisted visualization. Dissections of the transcortical and transcallosal craniotomies with transforaminal, transchoroidal, and interforniceal transventricular approaches were performed. The dissections were documented in a stepwise fashion using three-dimensional photographic image acquisition techniques and supplemented with representative cases to highlight pertinent surgical principles.

RESULTS

The anterior transcortical and interhemispheric corridors afford excellent access to the anterior two-thirds of the third ventricle with varying risks associated with frontal lobe versus corpus callosum disruption, respectively. The transcortical approach offers a more direct, oblique view of the ipsilateral lateral ventricle, whereas the transcallosal approach readily establishes biventricular access through a paramedian corridor. Once inside the lateral ventricle, intraventricular angled endoscopy further enhances access to the extreme poles of the third ventricle from either open transcranial approach. Subsequent selection of either the transforaminal, transchoroidal, or interforniceal routes can be performed through either craniotomy and is ultimately dependent on individual deep venous anatomy, the epicenter of ventricular pathology, and the concomitant presence of hydrocephalus or embryologic cava. Key steps described include positioning and skin incision; scalp dissection; craniotomy flap elevation; durotomy; transcortical versus interhemispheric dissection with callosotomy; the aforementioned transventricular routes; and their relevant intraventricular landmarks.

CONCLUSIONS

Approaches to the ventricular system for maximal safe resection of pediatric brain tumors are challenging to master yet represent foundational cranial surgical techniques. We present a comprehensive operatively oriented guide for neurosurgery residents that combines stepwise open and endoscopic cadaveric dissections with representative case studies to optimize familiarity with third ventricle approaches, mastery of relevant microsurgical anatomy, and preparation for operating room participation.

The Incidence of Depressed Skull Fractures Due to the Use of Pin-Type Head Frame Systems in the Adult Population: 10-year Experience of a Single Neurosurgical Center

OBJECTIVE

Pin-type head frame systems have become a worldwide standard procedure, but they can cause some complications on rare occasions. This study aimed to examine the incidence and associated risk factors of depressed skull fracture and related intracranial hematoma (DSFH) due to the use of head frames in our institute over the past 10 years.

METHODS

This study included 1749 patients who underwent neurosurgical surgeries using pin-type head frames, including the Mayfield (Integra NeuroSciences, Plainsboro, NJ) skull clamp (721 cases) and the Sugita (Mizuho Ikakogyo Co., Ltd., Tokyo, Japan) head frame (1028 cases). We retrospectively reviewed hospital records of our institute to identify cases of DSFH, and documented the type of head frame used, as well as patient characteristics.

RESULTS

The incidence of DSFH was 0.29% (5 of 1749 cases). All 5 cases had an associated epidural hematoma, with a single case having an additional dural laceration (without subdural damage). All perforation sites, located at the parietal bone near the pterion, occurred by the unilateral horizontal screw of the Sugita head frame. None of the patients experienced postoperative neurological decline.

CONCLUSIONS

Even in the adult population, the DSFH by the pin-type head frame can occur infrequently. Based on our results, we recommend that the following factors should be considered when the pin-type head frame is used for neurosurgical procedures: location of pin application, thickness and fragility of the skull, and adequate control of compressive forces exerted by the head frame.