Comparison of actual surgical outcomes and 3-dimensional surgical simulations

PURPOSE: The advent of imaging software programs has proved to be useful for diagnosis, treatment planning, and outcome measurement, but precision of 3-dimensional (3D) surgical simulation still needs to be tested. This study was conducted to determine whether the virtual surgery performed on 3D models constructed from cone-beam computed tomography (CBCT) can correctly simulate the actual surgical outcome and to validate the ability of this emerging technology to recreate the orthognathic surgery hard tissue movements in 3 translational and 3 rotational planes of space. MATERIALS AND METHODS: Construction of pre- and postsurgery 3D models from CBCTs of 14 patients who had combined maxillary advancement and mandibular setback surgery and 6 patients who had 1-piece maxillary advancement surgery was performed. The postsurgery and virtually simulated surgery 3D models were registered at the cranial base to quantify differences between simulated and actual surgery models. Hotelling t tests were used to assess the differences between simulated and actual surgical outcomes. RESULTS: For all anatomic regions of interest, there was no statistically significant difference between the simulated and the actual surgical models. The right lateral ramus was the only region that showed a statistically significant, but small difference when comparing 2- and 1-jaw surgeries. CONCLUSIONS: Virtual surgical methods were reliably reproduced. Oral surgery residents could benefit from virtual surgical training. Computer simulation has the potential to increase predictability in the operating room.

Prevalence of burnout among surgical residents and surgeons in Switzerland

Burnout is a pathologic reaction in response to long-term work-related stress. The aim of this study was 2-fold: first, to assess the prevalence and degree of burnout among surgical residents and surgeons in Switzerland and, second, to identify predictors of burnout in the surgical community. Four hundred five of 618 anonymous questionnaires (65.5%) were returned. Among respondents, 3.7% and 35.1% showed high and moderate degrees of burnout, respectively. Respondents with high and moderate degrees of burnout had higher summary scores of perceived stress (P < .001). In multiple logistic regression analysis, the strongest predictors of burnout were poor interaction with nurses, disturbances due to telephone consultations, and high overall workload. To reduce burnout, new work models should be sought, in addition to decreasing work intensity and workload rather than restricting work hours alone.

Trigonal and peritrigonal lesions of the lateral ventricle-surgical considerations and outcome analysis of 20 patients

The aim of this study is to review the results and clinical outcome of patients with surgically treated lesions within the trigone of the lateral ventricle. This is a retrospective case series of 20 (eight male, 12 female) patients with lesions of the trigone of the lateral ventricle operated between 1998 and 2008. All lesions were removed via the transcortical temporal and transcortical parietal route. Surgical complications and outcome were assessed using the modified Rankin Scale (mRS). There were four children and 16 adults with a mean age of 42?±?22 years (min?=?1, max?=?74). Eight (40%) lesions grew within the trigone of the dominant hemisphere. In 17 cases, the lesion was purely intraventricular, and in three cases, a slight paraventricular extension was seen. The mean size was 4.5 cm of maximal diameter. Surgical removal was achieved via the transcortical parietal route in 13 cases (65%) and the transcortical temporal route in seven cases (35%). In all cases, complete resection was possible. According to the mRS, 13 patients improved, five remained the same, and two were lost to follow-up. One patient had an increased visual field deficit postoperatively and new hemiparesis and aphasia, but returned to the preoperative level within a few weeks. In one patient, an acute myocardial infarction occurred due to previous cardiac stent placement and in-stent stenosis. Even large trigonal lesions can be resected with low morbidity using a transcortical approach depending on the peritrigonal extension of the tumor.

Diffuse descending necrotizing mediastinitis: surgical therapy and outcome in a single-centre series

Descending necrotizing mediastinitis (DNM) is a rare but rapidly progressing disease with a potentially fatal outcome, originating from odontogenical or cervical infections. The aim of this article was to give an up-to-date overview on this still underestimated disease, to draw the clinician's attention and particularly to highlight the need for rapid diagnosis and adequate surgical treatment.

Predictors of surgical, general and follow-up complications in lumbar spinal stenosis relative to patient age as emerged from the Spine Tango Registry

Published opinions regarding the outcomes and complications in older patients have a broad spectrum and there is a disagreement whether surgery in older patients entails a higher risk. Therefore this study examines the risk of surgery for lumbar spinal stenosis relative to age in the pooled data set of the Spine Tango registry.

Simulator training on pulsatile vascular models significantly improves surgical skills and the quality of carotid patch plasty

Vascular surgeons perform numerous highly sophisticated and delicate procedures. Due to restrictions in training time and the advent of endovascular techniques, new concepts including alternative environments for training and assessment of surgical skills are required. Over the past decade, training on simulators and synthetic models has become more sophisticated and lifelike. This study was designed to evaluate the impact of a 3-day intense training course in open vascular surgery on both specific and global vascular surgical skills.

Mastoiditis in children: a prospective, observational study comparing clinical presentation, microbiology, computed tomography, surgical findings and histology

The aim of this study was to obtain comprehensive data on clinical presentation, microbiology, computed tomography, surgical findings and histology in acute, sub-acute and chronic mastoiditis. We performed a prospective, observational study in children under 16 years of age presenting to our institution during the 2-year period beginning in April 2000. The children were examined and their condition treated in accordance with a standardized protocol elaborated by the paediatric, otolaryngology (ORL) and radiology departments. Thirty-eight patients were hospitalized (22 with acute mastoiditis, seven with sub-acute mastoiditis, nine with chronic mastoiditis). There were 30 complications present in 21 patients (55%). Streptococcus pyogenes was the most common pathogen (7/24 cases), followed by Streptococcus pneumoniae (4/24 cases). Mastoid surgery was performed in 29 patients. Histology of mastoid tissue revealed predominantly acute inflammation in two cases, mixed acute/chronic inflammation in 19 cases and predominantly chronic inflammation in seven cases. Radiologic data were evaluated retrospectively. Spiral, volume-based high-resolution (HR) computed tomography (CT) of the temporal bone had a sensitivity of 100%, specificity of 38%, positive predictive value (PPV) of 50% and negative predictive value (NPV) of 100% in detecting coalescence of mastoid trabeculae. Cranial CT with contrast had a sensitivity of 80%, specificity of 94%, PPV of 80% and NPV of 94% in identifying intra-cranial extension. Conclusion: histological evidence suggests that sub-acute/chronic infection underlies not only sub-acute and chronic mastoiditis, but most cases of acute mastoiditis as well. HR-CT of the temporal bone is effective in ruling out coalescence. Cranial CT is valuable in identifying intra-cranial extension. Cranial and HR-CT are recommended in the examination of children with mastoiditis.

An implantable carotid sinus baroreflex activating system: surgical technique and short-term outcome from a multi-center feasibility trial for the treatment of resistant hypertension

OBJECTIVES: To assess perioperative outcomes and blood pressure (BP) responses to an implantable carotid sinus baroreflex activating system being investigated for the treatment of resistant hypertension. METHODS: We report on the first seventeen patients enrolled in a multicenter study. Bilateral perivascular carotid sinus electrodes (CSL) and a pulse generator (IPG) are permanently implanted. Optimal placement of the CSL is determined by intraoperative BP responses to test activations. Acute BP responses were tested postoperatively and during the first four months of follow-up. RESULTS: Prior to implant, BP was 189.6+/-27.5/110.7+/-15.3 mmHg despite stable therapy (5.2+/-1.8 antihypertensive drugs). The mean procedure time was 202+/-43 minutes. No perioperative strokes or deaths occurred. System tests performed 1 or up to 3 days postoperatively resulted in significant (all p < or = 0.0001) mean maximum reduction, with standard deviations and 95% confidence limits for systolic BP, diastolic BP and heart rate of 28+/-22 (17, 39) mmHg, 16+/-11 (10, 22) mmHg and 8+/-4 (6, 11) BPM, respectively. Repeated testing during 3 months of therapeutic electrical activation demonstrated a durable response. CONCLUSIONS: These preliminary data suggest an acceptable safety of the procedure with a low rate of adverse events and support further clinical development of baroreflex activation as a new concept to treat resistant hypertension.

Non-photorealistic rendering of virtual implant models for computer-assisted fluoroscopy-based surgical procedures

Surgical navigation systems visualize the positions and orientations of surgical instruments and implants as graphical overlays onto a medical image of the operated anatomy on a computer monitor. The orthopaedic surgical navigation systems could be categorized according to the image modalities that are used for the visualization of surgical action. In the so-called CT-based systems or 'surgeon-defined anatomy' based systems, where a 3D volume or surface representation of the operated anatomy could be constructed from the preoperatively acquired tomographic data or through intraoperatively digitized anatomy landmarks, a photorealistic rendering of the surgical action has been identified to greatly improve usability of these navigation systems. However, this may not hold true when the virtual representation of surgical instruments and implants is superimposed onto 2D projection images in a fluoroscopy-based navigation system due to the so-called image occlusion problem. Image occlusion occurs when the field of view of the fluoroscopic image is occupied by the virtual representation of surgical implants or instruments. In these situations, the surgeon may miss part of the image details, even if transparency and/or wire-frame rendering is used. In this paper, we propose to use non-photorealistic rendering to overcome this difficulty. Laboratory testing results on foamed plastic bones during various computer-assisted fluoroscopybased surgical procedures including total hip arthroplasty and long bone fracture reduction and osteosynthesis are shown.