Erich O. Richter

Feasibility of Anterior Cervical Discectomy and Fusion as an Outpatient Procedure

BACKGROUND Anterior cervical discectomy and fusion (ACDF) procedures are increasingly being managed on an outpatient basis. Currently there are no definitive guidelines within the literature that delineate which patient population can safely be managed as such. The purpose of this study is to demonstrate that ACDF procedures, within a selective patient population at our institution, can be safely performed on an outpatient basis. METHODS This is a retrospective chart review within one physicians practice of patients undergoing instrumented ACDF procedures using allograft. This sample included 117 patients who underwent one- and two-level ACDF procedures from November 2005 to April 2009. Hospital length of stay and hospital readmissions were noted. Complication rates in the outpatient population were assessed to determine the feasibility of outpatient management for selective patients undergoing ACDF procedures. RESULTS A total of 59 patients (50%) were treated on an outpatient basis. Sixty-eight patients underwent single level ACDF procedures, 38 patients (56%) of which were discharged on the same day. Forty-nine patients underwent two-level ACDF procedures, 21 patients (43%) of which were discharged on the same day. There was one complication (1.4%) in patients who were discharged on the same day. That patient required readmission for 23-hour observation secondary to neck swelling. CONCLUSIONS ACDF procedures involving single and two-level fusions can safely be performed on an outpatient basis. Complication rates associated with this procedure are low, with critical postoperative complications involving respiratory compromise occurring very infrequently and in the immediate postoperative period.

Awake vs. asleep placement of spinal cord stimulators: A cohort analysis of complications associated with placement - Commentary

Introduction:  Patients will typically undergo awake surgery for permanent implantation of spinal cord stimulation (SCS) in an attempt to optimize electrode placement using patient feedback about the distribution of stimulation‐induced paresthesia. The present study compared efficacy of first‐time electrode placement under awake conditions with that of neurophysiologically guided placement under general anesthesia.

ANATOMIC STUDY OF THE INFRAORBITAL FORAMEN FOR RADIOFREQUENCY NEUROTOMY OF THE INFRAORBITAL NERVE. Commentary

OBJECTIVE To examine the anatomy of the infraorbital canal and foramen and the angles at which a radiofrequency probe must be directed to enter the infraorbital foramen and canal, as a guide to performing radiofrequency ablation of the infraorbital nerve in patients with relative or absolute contraindications to lesions of the trigeminal ganglion or posterior root. METHODS Eleven cadaveric skulls were studied. The infraorbital nerve, after passing through the infraorbital foramen, enters the infraorbital canal and groove in the floor of the orbit before reaching the foramen rotundum. Small probes were placed through the foramen into the infraorbital canal, and pictures were taken in the anteroposterior and sagittal planes. The pictures were analyzed using the ImageTool program (University of Texas Health Science Center, San Antonio, TX) to calculate the anteroposterior and sagittal angles of the probe. The distances of the foramen from the midline, lateral edge of the anterior nasal aperture, and inferior orbital rim were examined. RESULTS A probe introduced through the cheek from below and medial to the foramen and directed upward and laterally at an angle of approximately 22 degrees in the coronal plane and 120 degrees in the sagittal plane toward a point approximately 26 mm from the midline and 8 mm below the inferior orbital rim will penetrate the infraorbital foramen for placement of the probes tip in the infraorbital canal. CONCLUSION The coordinates for placement of the radiofrequency probe through the infraorbital foramen and into the infraorbital canal are reviewed, along with a discussion of pitfalls in radiofrequency ablation of the nerve.

Percutaneous Cephalocaudal Implantation of Epidural Stimulation Electrodes Over Sacral Nerve Roots—A Technical Note on the Importance of the Lateral Approach

Objective:  Idiopathic overactive bladder, urgency‐frequency syndromes, interstitial cystitis, pudendal neuralgia, vulvodynia, prostadynia, and coccygodynia have been effectively treated with sacral nerve root modulation. This is most commonly performed with placement of electrodes via a transforaminal approach, predominately to the S3 foramen. This approach is limited by a high lead migration rate and the limitations of stimulating a single nerve root. Beginning in the 1990s, some centers began pursuing retrograde percutaneous placement from the lumbar spine, but adoption of this technique was limited by the technical difficulty of the approach.

Linguistic Testing During ON/OFF States of Electrical Stimulation in the Associative Portion of the Subthalamic Nucleus

Introduction:  Long‐term studies of subthalamic nucleus (STN) deep brain stimulation (DBS) in patients with Parkinsons disease have shown potential cognitive and linguistic side‐effects. In this pilot study, we examined whether direct monopolar stimulation in the ventral, associative STN would result in language effects.

Air embolus to arachnoid cyst as a rare delayed complication of intrathecal medication delivery.

Introduction:  Intrathecal (IT) medication delivery is a commonly used technique for the treatment of chronic intractable pain. Cerebrospinal fluid (CSF) loculation at the catheter tip has been described as a cause of progressive loss of drug effect that can often be difficult to diagnose.

EMG/SSEP Monitoring During Sacral Neuromodulation

Sacral root neuromodulation has been employed for the treatment of idiopathic overactive bladder, urgency-frequency syndromes, interstitial cystitis, pudendal neuralgia, vulvodynia, coccygodynia, and a variety of chronic pelvic pain (CPP) syndromes.

EMG/SSEP Monitoring During Thoracolumbar Spinal Cord Stimulation

Intraoperative neurophysiological monitoring has become a routine procedure in complex spine surgery. Somatosensory-evoked potential (SSEP) recording has been advocated to monitor the functional integrity of the nervous system during surgical manipulation.

Use of a Touchscreen Monitor to Streamline Intraoperative Deep Brain Stimulation Research

Background:Creating a somatotopic map of the subthalamic nucleus of a patient undergoing deep brain stimulation requires extra procedural steps, hardware, and personnel and can result in prolonged procedural time. Objective:ClockSynch, a custom program used to collect intraoperative data, requires user input during surgery. A small touchscreen may simplify the researcher’s interaction with data collection software and minimize the impact of the research protocol on overall operative time. This possibility was investigated using the multi-input multioutput (MIMO) 720S, a lightweight touchscreen. Methods:ClockSynch is designed to be used with the MIMO 720S in touchscreen mode. During intraoperative data collection, the researcher used the MIMO to control ClockSynch without interacting with the computer running the program. Results:Once correctly configured, the MIMO was used in the operating room without any incidence of failure during intraoperative data collection. It also had the advantage of being compact and lightweight enough to be placed at any location around the patient and allowed the primary researcher to interact with the research software and the patient simultaneously. Conclusions:Small, touchscreen devices such as the MIMO 720S can facilitate intraoperative research by providing a simple interface with research software that allows a single researcher to perform more duties. Such devices also minimize the impact of research protocol on operative time.

Synchronizing microelectrode and electronic goniometer data using a pseudo-random binary signal

Abstract Intra-operative investigation of the subthalamic nucleus (STN) requires concurrent measurement of microelectrode voltage, electrode depth and joint movement during deep brain stimulation (DBS) surgery. Commercial solutions to this problem exist but are more expensive. Multiple instruments from different manufacturers can collect the same data, but data from incompatible instruments are collected on disparate clocks, precluding quantitative analysis. A pseudo-random binary signal recorded simultaneously by each set of instruments allows for chronological reconciliation. A custom program collects microelectrode data while simultaneously sending a pseudo-random binary signal to instruments measuring joint movement. The record of this signal is later used to express microelectrode voltage and joint position in a single chronological frame of reference. ClockSynch was used in 15 DBS procedures. After each surgery, records of microelectrode and joint movement were successfully chronologically reconciled. In conclusion, a pseudo-random binary signal integrates disparate systems of instrumentation at a significantly decreased cost.