James J. Lynch

Venous air embolism in sitting and supine patients undergoing vestibular schwannoma resection.

OBJECTIVE This study retrospectively compares the incidence of venous air embolism (VAE) detection and morbidity in the sitting and supine positions. All patients underwent vestibular schwannoma resection via the retrosigmoid approach by a single surgical team. METHODS A total of 432 consecutive operations were reviewed, 222 of which were performed with the patients in the sitting position and 210 of which were performed with the patients in the supine position. Charts were reviewed for evidence of intraoperative VAE, intraoperative hypotension secondary to VAE, postoperative morbidity related to VAE, and other variables to compare the groups. RESULTS This study demonstrated a 28% incidence of VAE detection when patients were in the sitting position compared to a 5% incidence of VAE detection when patients were in the supine position (P < 0.0001). Intraoperative hypotension secondary to VAE was noted in 1.8% of the sitting patients and 1.4% of the supine patients (P=0.72, no significant difference). Postoperative morbidity caused by VAE was noted in one sitting patient (0.5%) (pulmonary edema) and in no supine patients (P=0.48, no significant difference). Blood loss was slightly greater in the supine group, and operative times were similar in both groups, despite that the average tumor size of patients operated on in the sitting position was 2.8 cm versus 2.2 cm in the supine group (P < 0.0001). CONCLUSION Our results indicate that although there is a higher incidence of VAE detection in sitting patients, the morbidity is not statistically greater. We conclude that because morbidity from VAE is similar in either position, patient positioning should be based on surgical team preference.

Magnetic resonance imaging clarity of the Bryan, Prodisc-C, Prestige LP, and PCM cervical arthroplasty devices.

Study Design. Prospective, randomized, controlled and double-blinded study on imaging of artificial discs. Objective. The purpose of this study is to compare postoperative imaging characteristics of the 4 currently available cervical arthroplasty devices at the level of implantation and at adjacent levels. Summary of Background Data. Cervical arthroplasty is being performed increasingly frequently for degenerative disc disease and, in most cases, with frank neural compression. Unlike lumbar arthroplasty, performed mainly for axial back pain, decompression of neural elements may need to be confirmed with postoperative imaging after cervical arthroplasty. Methods. Preoperative and postoperative magnetic resonance imaging scans of 20 patients who had undergone cervical arthroplasty were assessed for imaging quality. Five cases each of the Bryan® (Medtronic Sofamor Danek, Memphis, TN), Prodisc-C® (Synthes Spine, Paoli, PA), Prestige LP® (Medtronic Sofamor Danek), and PCM® devices (Cervitech, Rockaway, NJ) were analyzed. Six blinded spinal surgeons scored twice sagittal and axial T2-weighted images using the Jarvik 4-point scale. Statistical analysis was performed comparing quality before surgery and after disc implantation at the operated and adjacent levels and between implant types. Results. Moderate intraobserver and interobserver reliability was noted. Preoperative images of patients in all implant groups had high-quality images at operative and adjacent levels. The Bryan® and Prestige LP® devices allowed satisfactory visualization of the canal, exit foramina, cord, and adjacent levels after arthroplasty. Visualization was significantly impaired in all PCM® and Prodisc-C® cases at the operated level in both the spinal canal and neural foramina. At the adjacent levels, image quality was statistically poorer in the PCM® and Prodisc-C® than those of Prestige LP® or Bryan®. Conclusions. Postoperative visualization of neural structures and adjacent levels after cervical arthroplasty is variable among current available devices. Devices containing nontitanium metals (cobalt-chrome-molybdenum alloys in the PCM® and Prodisc-C®) prevent accurate postoperative assessment with magnetic resonance imaging at the surgical and adjacent levels. Titanium devices, with or without polyethylene (Bryan® disc or Prestige LP®), allow for satisfactory monitoring of the adjacent and operated levels. This information is crucial for any surgeon who wishes to assess adequacy of neural decompression and where monitoring of adjacent levels is desired.

The successful application of simulation-based training in thoracic surgery residency

OBJECTIVE We developed and tested a clinical simulation program in the principles and conduct of cardiopulmonary bypass with the aim of improving confidence and proficiency in this critical aspect of cardiac surgical care. METHODS Fifteen residents from 6 resident-training programs who reported no prior cardiopulmonary bypass observation or simulation-based perfusion experience participated in a cardiopulmonary bypass course involving both didactic lectures and hands-on simulation. A computer-controlled hydraulic model of the human circulation was used in a specifically designed multidisciplinary simulation center environment to give the participants hands-on training with both basic operations and specific perfusion crisis scenarios. Pretraining and posttraining assessments concerning confidence, knowledge, and applications with regard to cardiopulmonary bypass were administered and compared. RESULTS Likert scale scores on confidence-related items increased significantly (P < .001), from 59% +/- 16% to 92% +/- 8%. Pretraining versus posttraining scores (72% +/- 14%) on similar cognitive items were not significantly different (P=.3636). Scores on similar open-ended application items before and after training improved from 62% +/- 25% to 85+/-10% (P < .0001). All subjects agreed that simulation-based cardiopulmonary bypass training was superior to classroom- and clinic-based education and that the scenarios enhanced their learning experience. CONCLUSIONS Simulation-based cardiopulmonary bypass training appears to be an effective technique to build the confidence of thoracic surgery residents regarding knowledge and applications. Scenario-based practice in a specifically designed simulated environment is a valuable adjunct to traditional educational methods and has the potential to improve the training of thoracic residents.

Surgical treatment of fibrous dysplasia of the skull in children

Introduction: We evaluate the role of surgery in the treatment of fibrous dysplasia of the skull in children. Methods: We identified 48 consecutive cases of fibrous dysplasia of the skull that were surgically treated at a single institution over a 23-year interval. The 28 patients that initially presented during the first two decades of life were selected for further analysis. Presenting symptoms, signs, surgical treatment, surgical outcome and the state of the disease at the extended follow-up interval were recorded. Results: Fibrous dysplasia of the skull in children most often involved the frontal, sphenoid and ethmoid bones. Most patients presented with facial asymmetry or proptosis. A gross total resection was achieved in 7 patients, subtotal resection in 17 patients, and 4 patients underwent biopsy alone. Over the follow-up interval, 7 patients had symptomatic progression of subtotally resected fibrous dysplasia and 3 patients had asymptomatic progression. The extent of resection was correlated with recurrence risk. Conclusions: In order to prevent progression of disease, an attempt at gross total resection is indicated in cases of fibrous dysplasia of the skull in childhood where the risk of neurologic morbidity is low and cosmetic results will be acceptable.

Simulation-Based Postcardiotomy Extracorporeal Membrane Oxygenation Crisis Training for Thoracic Surgery Residents

BACKGROUND We developed and tested a clinical simulation program in the principles and conduct of postcardiotomy extracorporeal membrane oxygenation (ECMO) with the aim of improving confidence, proficiency, and crisis management. METHODS Twenty-three thoracic surgery residents from unique residency programs participated in an ECMO course involving didactic lectures and hands-on simulation. A current postcardiotomy ECMO circuit was used in a simulation center to give residents training with basic operations and crisis management. Pretraining and posttraining assessments concerning confidence and knowledge were administered. Before and after the training, residents were asked to identify components of the ECMO circuit and manage crisis scenarios, including venous line collapse, arterial hypertension, and arterial desaturation. RESULTS In the hands-on portion, residents had difficulty identifying the gas source and flow rate, centrifugal pump head inlet, and oxygenator outflow line. Timely and accurate ECMO component identification improved significantly after training. The arterial desaturation crisis scenario gave the residents difficulty, with only 22% providing the appropriate treatment recommendations in a timely and accurate fashion. At the end of the simulation training, most residents were able to manage the crises correctly in a timely manner. Posttraining confidence-related scores increased significantly. Most of the residents strongly recommended the course to their peers and reported simulation-based training was helpful in their postcardiotomy ECMO education. CONCLUSIONS We developed a simulation-based postcardiotomy ECMO training program that resulted in improved ECMO confidence in thoracic surgery residents. Crisis management in a simulated environment enabled residents to acquire technical and behavioral skills that are important in managing critical ECMO-related problems.

Comparison of Electroencephalography and Cerebral Oximetry to Determine the Need for In-Line Arterial Shunting in Patients Undergoing Carotid Endarterectomy

OBJECTIVE To compare cerebral near-infrared regional spectroscopy (NIRS) with the 12-lead electroencephalogram for the detection of ischemia during carotid artery clamping for carotid endarterectomy (CEA). DESIGN Prospective, observational. SETTING Single, tertiary care center. PARTICIPANTS Ninety patients older than 18 undergoing elective, unilateral CEA. INTERVENTIONS In addition to EEG monitoring, all patients underwent continuous blinded NIRS monitoring with sensors placed bilaterally above the supraorbital ridge. MEASUREMENTS AND MAIN RESULTS Seventeen patients were excluded, leaving 73 patients available for evaluation. Four patients (5.5%) required shunting based on EEG findings. Changes in cerebral oxygen saturation (rSO2) were assessed on the operative side using the average value for the 1 minute prior to cross-clamp and the lowest rSO2 value the first 5 minutes postclamp. Each 1% absolute decrease and each 1% relative decrease from baseline conferred a 50% increase in the need for shunt placement (OR 1.5; 95% CI (1.03-2.26); p = 0.03 and OR 1.4; 95% CI (1.02-1.81); p = 0.04 respectively). Sensitivity, specificity, and positive and negative predictive values were determined using significant cutoffs of≥5% absolute change or≥10% relative change. Positive predictive value was low (<25%) for both absolute and relative changes. CONCLUSIONS A decrease in rSO2 during carotid cross-clamping for CEA is associated with EEG-determined need for shunting, but the positive predictive value is low. Using the above cutoffs in the current series would have resulted in an increase in the shunt rate by approximately 20% when it was not indicated by EEG.

Surgical management of traumatic thoracic spondyloptosis : Review of 2 cases

Spondyloptosis due to trauma is a very rare injury typically associated with motor vehicle accidents and typically at the lumbosacral junction. This report describes two patients with T6-7 and T12-L1 spondyloptosis secondary to trauma. The former was a 36-year-old man who was pinned under a 200 kg hay bale, suffering immediate paraplegia and undergoing successful posterior reduction and stabilization via a single stage posterior approach. Two years after his injury he has not developed any new deformity or neurological deterioration. The latter was a 22-year-old miner who was thrown against the ceiling of a coalmine and suffered a hyperflexion injury resulting in an immediate T12 paraplegia. Again successful reduction and stabilization was able to be achieved through pedicle screw instrumentation via a single-stage posterior approach. These two patients are the first reported cases of traumatic thoracic spondyloptosis. This report describes the rationale, likely mechanisms and surgical technique required for operative reduction and stabilization via a single-stage posterior approach.

Robotic Mitral Valve Repair: A Review of Anesthetic Management of the First 200 Patients

OBJECTIVE The aim of this study was to describe the evolution in anesthetic technique used for the first 200 patients undergoing robotic mitral valve surgery. DESIGN A retrospective review. SETTING A single tertiary referral academic hospital. PARTICIPANTS Two hundred consecutive patients undergoing robotic mitral valve surgery using the da Vinci Surgical System (Intuitive Surgical, Inc., Sunnyvale, CA) at Mayo Clinic Rochester. INTERVENTIONS None. MEASUREMENTS AND MAIN RESULTS After obtaining institutional review board approval, surgical and anesthetic data were recorded. For analysis, patients were placed in 4 groups, each containing 50 consecutive patients, labeled Quartiles 1 to 4. Over time, there were statistically significant decreases in cardiopulmonary bypass and aortic cross-clamp times. Significant differences in the anesthetic management were shown, with a reduction of intraoperative fentanyl and midazolam doses, and the introduction of paravertebral blockade in Quartile 2. There was a reduction of time between incision closure and extubation, and nearly 90% of patients were extubated in the operating room in Quartiles 3 and 4. Despite changes to the intraoperative analgesic management, and focus on earlier extubation, there were no differences seen in visual analog scale (VAS) pain scores over the 4 quartiles. Reductions were seen in total intensive care unit and hospital length of stay during the study period. CONCLUSIONS Changes to the practice, including efforts to limit intraoperative opioid administration and the addition of preoperative paravertebral blockade, helped facilitate earlier extubation. In the second half of the study period, close to 90% of patients were extubated in the operating room safely and without delaying patient transition to the intensive care unit.

Use of Paravertebral Blockade to Facilitate Early Extubation after Minimally Invasive Cardiac Surgery

We retrospectively reviewed the first 14 patients who received preoperative paravertebral blockade prior to minimally invasive cardiac surgical procedures. The use of paravertebral blockade along with an anesthetic technique designed to facilitate rapid recovery allowed early extubation in the operating room or intensive care unit in all but one patient. Extubated patients leaving the operating room were comfortable. No postoperative respiratory complications occurred.

Clinical application of a novel video camera laryngoscope: a case series venturing beyond the normal airway ☆

The McGRATH Video Laryngoscope Series 5 is an example of indirect laryngoscopic equipment. Experience using this device to safely intubate the trachea of awake and asleep patients with known or anticipated difficult airways is presented.