Biomechanical comparison of occipitoatlantal screw fixation techniques

OBJECT: The stability provided by 3 occipitoatlantal fixation techniques (occiput [Oc]-C1 transarticular screws, occipital keel screws rigidly interconnected with C-1 lateral mass screws, and suboccipital/sublaminar wired contoured rod) were compared. METHODS: Seven human cadaveric specimens received transarticular screws and 7 received occipital keel-C1 lateral mass screws. All specimens later underwent contoured rod fixation. All conditions were studied with and without placement of a structural graft wired between the skull base and C-1 lamina. Specimens were loaded quasistatically using pure moments to induce flexion, extension, lateral bending, and axial rotation while recording segmental motion optoelectronically. Flexibility was measured immediately postoperatively and after 10,000 cycles of fatigue. RESULTS: Application of Oc-C1 transarticular screws, with a wired graft, reduced the mean range of motion (ROM) to 3% of normal. Occipital keel-C1 lateral mass screws (also with graft) offered less stability than transarticular screws during extension and lateral bending (p < 0.02), reducing ROM to 17% of normal. The wired contoured rod reduced motion to 31% of normal, providing significantly less stability than either screw fixation technique. Fatigue increased motion in constructs fitted with transarticular screws, keel screws/lateral mass screw constructs, and contoured wired rods, by means of 19, 5, and 26%, respectively. In all constructs, adding a structural graft significantly improved stability, but the extent depended on the loading direction. CONCLUSIONS: Assuming the presence of mild C1-2 instability, Oc-C1 transarticular screws and occipital keel-C1 lateral mass screws are approximately equivalent in performance for occipitoatlantal stabilization in promoting fusion. A posteriorly wired contoured rod is less likely to provide a good fusion environment because of less stabilizing potential and a greater likelihood of loosening with fatigue.     

Surgical management of primary and metastatic sarcoma of the mobile spine

OBJECT: Sarcomas of the spine are a challenging problem due to their frequent and extensive involvement of multiple spinal segments and high recurrence rates. Gross-total resection to negative margins, with preservation of neurological function and palliation of pain, is the surgical goal and may be achieved using either intralesional resection or en bloc excision. The authors report outcomes of surgery for primary and metastatic sarcomas of the mobile spine in a large patient series. METHODS: A retrospective review of patients undergoing resection for sarcomas of the mobile spine between 1993 and 2005 was undertaken. Sarcomas were classified by histology study results and as either primary or metastatic. Details of the surgical approach, levels of involvement, and operative complications were recorded. Outcome measures included neurological function, palliation of pain, local recurrence, and overall survival. RESULTS: Eighty patients underwent 110 resections of either primary or metastatic sarcomas of the mobile spine. Twenty-nine lesions were primary sarcomas (36%) and 51 were metastatic sarcomas (64%). Intralesional resections were performed in 98 surgeries (89%) and en bloc resections were performed in 12 (11%). Median survival from surgery for all patients was 20.6 months. Median survival for patients with a primary sarcoma of the spine was 40.2 months and was 17.3 months for patients with a metastatic sarcoma. Predictors of improved survival included a chondrosarcoma histological type and a better preoperative functional status, whereas osteosarcoma and a high-grade tumor were negative influences on survival. Multivariate analysis showed that only a high-grade tumor was an independent predictor of shorter overall survival. American Spinal Injury Association scale grades were maintained or improved in 97% of patients postoperatively, and there was a significant decrease in pain scores postoperatively. No significant differences in survival or local recurrence rates between intralesional or en bloc resections for either primary or metastatic spine sarcomas were found. CONCLUSIONS: Surgery for primary or metastatic sarcoma of the spine is associated with an improvement in neurological function and palliation of pain. The results of this study show a significant difference in patient survival for primary versus metastatic spine sarcomas. The results do not show a statistically significant benefit in survival or local recurrence rates for en bloc versus intralesional resections for either metastatic or primary sarcomas of the spine, but this may be due to the small number of patients undergoing en bloc resections.     

Efficacy of Trans-septal Trans-sphenoidal Surgery in Correcting Visual Symptoms Caused by Hematogenous Metastases to the Sella and Pituitary Gland

The rate of symptomatic improvement of visual symptoms associated with hematogenous metastases to the sella and pituitary was evaluated retrospectively in seven patients (five men, two women; mean age, 52.3 years) with primarily visual symptoms (diplopia alone in three, diplopia with blurred vision in one, blurred vision alone in one, loss of peripheral vision in one, and unilateral complete blindness in one). Symptom duration ranged from 0.5 to 2 months. The primary diseases were non-small cell lung cancer in two patients, renal cell carcinoma in two patients, prostate cancer in two patients, and medullary thyroid carcinoma in one patient. All patients had widespread metastatic disease. Three patients had a suprasellar tumoral component. One patient had a clival extension, and one patient had extension into the cavernous sinus. All underwent trans-sphenoidal surgery to correct visual symptoms. Gross total resection was achieved in three patients. Subtotal resections and a partial resection were performed in three patients and one patient, respectively. Surgical blood loss averaged 282 mL. One patient died from sepsis. Five patients developed complications (cerebrospinal fluid leakage in three, diabetes insipidus in two, anterior pituitary dysfunction in two, and colitis in one). At a mean follow-up of 15 months, three patients were alive. Visual symptoms improved in five patients and were unchanged in two. Trans-sphenoidal surgery helped improve visual symptoms in most patients. The morbidity rate was high and likely related to the locally destructive and extensive nature of the lesions in overall morbid patients with widespread metastatic disease. Unless nonoperative measures can provide equal results, however, this approach provides reasonable palliation.     

The clinical, electrophysiologic, and surgical characteristics of peripheral nerve injuries caused by gunshot wounds in adults: a 40-year experience

BACKGROUND: There are few large-volume studies on the repair of peripheral nerve lesions caused by gunshot wounds. In this study, the results of peripheral nerve repair are analyzed, and the factors influencing the outcome are investigated. METHODS: During a 40-year period, 2210 peripheral nerve lesions in 2106 patients who sustained gunshot injury were treated surgically in the Department of Neurosurgery. One thousand thirty-four patients had shrapnel injury, and 1072 patients had missile injury. Twelve peripheral nerves were included in this study, and all of them were repaired by direct suture, using nerve graft, or neurolysis. All patients underwent neurologic and electrophysiologic evaluations in the preoperative period and postoperatively at the end of the follow-up period. The mean time of follow-up was 2.6 years. Final outcome was based on the motor, sensory, and electrophysiologic recoveries, and a patient judgment scale. RESULTS: Using the muscle grading scale, sensory grading scale, EMNG, and patient judgments, the maximal recovery was achieved in the subscapular nerve, but there were only 4 subscapular nerve lesions, which is not sufficient for a statistically significant outcome. Furthermore, the tibial, median, and femoral nerve lesions showed the best recovery rate, whereas the peroneal nerve, ulnar nerve, and brachial plexus lesions had the worst. CONCLUSION: Type of the peripheral nerve, injury (repair) level, associated injuries, electrophysiologic findings, operation time, intraoperative findings, surgical techniques, and postoperative physical rehabilitation are the prognostic factors for peripheral nerve lesions due to gunshot wounds.     

Predicting complications in elderly patients undergoing lumbar decompression

A retrospective chart review of 68 patients 70 years of age or older who underwent decompressive procedures of the lumbar spine with or without fusion for benign conditions was performed to determine the ability of preoperative assessment of medical comorbidities to predict early postoperative complications. Patients 70 years of age or older who underwent decompressive procedures on the lumbar spine with or without fusion from January 1, 1990 to June 30, 1996 were identified. A chart review focused on preoperative comorbid diseases and early postoperative complications. A telephone survey was performed to assess patient satisfaction. Thirty-four women and 34 men with an average of 76.5 years averaged 1.6 comorbidities. Thirteen patients did not have comorbidities. The weighted comorbidity index resulted in an average score of 1.9. Eighty-five percent of the patients underwent posterolateral fusion. The total complication rate was 40%. Serious complications potentially affecting quality of life occurred in 12% of patients. The early mortality rate was 1.4%. The authors were unable to show a significant relationship between comorbidities and postoperative complications. Seventy-one percent of the 44 patients who were contacted at an average 42 months postoperatively were satisfied with their outcome. Elderly patients can safely undergo lumbar spinal procedures with an outcome similar to younger patients.     

Application of 2 vibrators salvages ejaculatory failures to 1 vibrator during penile vibratory stimulation in men with spinal cord injuries

PURPOSE: Penile vibratory stimulation is the treatment of first choice for anejaculation in men with spinal cord injury. Nonresponders to penile vibratory stimulation are usually referred for electroejaculation or surgical sperm retrieval. Compared to penile vibratory stimulation these methods are invasive and usually yield lower total motile sperm, potentially limiting options for assisted reproductive technologies. To avoid these less than ideal options a simple method to salvage penile vibratory stimulation failures would be of benefit to spinal cord injured patients. We investigated the recovery rate when 2 vibrators were used to salvage ejaculatory failures to 1 vibrator in men with spinal cord injury. MATERIALS AND METHODS: A retrospective chart review was performed in 297 spinal cord injured men who underwent a total of 965 trials of penile vibratory stimulation at our center between 1991 and 2006. Only trials with high amplitude vibrators were examined. All men underwent 2 or more penile vibratory stimulation trials using 1 vibrator applied to the dorsum or frenulum of the glans penis. Men failing to ejaculate with 1 vibrator received 1 or more trials in which the glans penis was then sandwiched between 2 vibrators. RESULTS: Of all men 49% and 57% of those whose level of injury was T10 or above responded to penile vibratory stimulation with 1 vibrator. Of failures with 1 vibrator 22% responded to penile vibratory stimulation with 2 vibrators. CONCLUSIONS: Application of 2 vibrators salvaged ejaculatory failures to 1 vibrator during penile vibratory stimulation procedures in men with spinal cord injury. This simple penile vibratory stimulation sandwich method is recommended before referring patients for electroejaculation or surgical sperm retrieval.     

Left ventricular hypertrophy and chronic fluid overload in peritoneal dialysis patients

Purpose

Cardiovascular disease is the leading cause of mortality in dialysis patients with left ventricular hypertrophy (LVH) being an important predictor of mortality. We wanted to determine the prevalence of LVH in peritoneal dialysis (PD) patients and factors contributing to it.

Methods

This is a cross-sectional study assessing LVH using echocardiogram in PD patients. Left ventricular mass index (LVMI) was calculated to determine LVH. Chronic fluid overload (overhydration) was assessed using the body composition monitor, and blood pressure (BP) was measured using 24-h ambulatory BP monitoring.

Results

Thirty-one patients (21 females:10 males, 48.97 ± 14.50 years and dialysis vintage 40.0 ± 28.9 months) were studied. More than two-thirds (77.4 %) were hypertensive, and a third (35.5 %) were diabetic. Baseline data included mean serum albumin (37.34 ± 4.43 g/l), weekly Kt/V (2.02 ± 0.23), residual renal function of 68 (0–880) ml and ultrafiltration of 1,606.9 ± 548.6 ml. Majority of patients (80.6 %) had LVH on echocardiogram with LVMI of 136.5 ± 37.8 g/m² and overhydration of 2.23 ± 1.77 l. Average systolic BP, diastolic BP and mean arterial pressure were 141.2 ± 23.3, 90.8 ± 19.7 and 107.6 ± 19.6 mmHg, respectively. Patients with LVH had a lower serum albumin (p = 0.003), were more overhydrated (p = 0.010) and were on higher number of anti-hypertensive agents (p ≤ 0.001). Predictors of LVMI were overhydration (p = 0.002), the presence of diabetes (p = 0.008) and the number of anti-hypertensive agents used (p = 0.026). However, overhydration (p = 0.007) was the main predictor of LVH on multivariate analysis.

Conclusion

Overhydration is strongly associated with LVH in PD patients.     

The effect of fluoxetine on ischemia–reperfusion after aortic surgery in a rat model

Background

Aortic ischemia–reperfusion (IR) is an important factor in the development of postoperative acute lung injury after abdominal aortic surgery. The aim of the present study was to examine the effect of fluoxetine (Flx), a selective serotonin reuptake inhibitor widely used as a preoperative anxiolytic, on lung injury induced by abdominal aortic IR in rats.

Methods

Wistar rats were randomized into three groups (n = 7 per group): (1) control (sham laparotomy); (2) IR without Flx (60-min ischemia and 120-min reperfusion); (3) IR with Flx (Flx + IR) (Flx 20 mg/kg/d, intraperitoneally for 3 d before surgery). Lung tissue samples and bronchoalveolar lavage (BAL) were obtained for biochemical analysis of oxidative status. Ischemia-modified albumin (IMA) level and protein concentrations in BAL and lung wet to dry weight ratios were determined. Histologic evaluation of the lung tissues was also performed.

Results

IR without Flx led to significant increase in lipid hydroperoxide, malondialdehyde, and pro-oxidant–antioxidant balance and decrease in superoxide dismutase, glutathione, and ferric reducing antioxidant power activities (P < 0.05 versus control), whereas Flx was able to restore these parameters (P > 0.05 versus control) and decrease IMA level (P < 0.01 versus control) and protein concentration (P < 0.05 versus control) in BAL and wet to dry lung weight ratio. Histologic evaluation showed that Flx attenuated the morphologic changes associated with lung injury.

Conclusions

The results indicate that Flx confers protection against aortic IR-induced lung oxidative stress and cellular integrity. IMA levels in BAL may be used as a follow-up marker for the efficacy of treatment in lung injury.     

The prevalence of anxiety and depression among end-stage renal disease patients on hemodialysis in Saudi Arabia

Depression commonly overlaps with uremic symptoms, but anxiety is less commonly studied among renal patients. The symptoms of medical illness, along with the psychological and social stresses that often accompany a debilitating chronic disease, are thought to produce deleterious psychological consequences. We sought to determine the prevalence and predictors of anxiety and depression among Saudi dialysis patients in Makkah. A cross-sectional study of anxiety and depression among end-stage renal disease (ESRD) patients in Makkah was conducted in November 2011. The Hospital Anxiety and Depression Scale (HADS) was used to screen for anxiety and depression. Participants’ demographic data, possible stressors and past psychiatric history were obtained. All participants were Saudi ESRD patients on maintenance hemodialysis. According to HADS, 57 (21.1%) patients were probable cases of anxiety and 63 (23.3%) were probable cases of depression. Only 32 (11.3%) were diagnosed with depression or anxiety before ESRD onset. Age was a significant predictor of anxiety and depression diagnoses. Major family problems (p?=?0.001) were also a significant predictor of anxiety. Anxiety and depressive symptoms are prevalent among ESRD patients in Makkah, and anxiety can be predicted by family factors. Early detection, management and family support might improve clinical outcomes.     

Transvaginal Route for Kidney Extraction in Laparoscopic Donor Nephrectomy

Background and Objectives:

The aim of this retrospective study was to compare conventional laparoscopic living-donor nephrectomy with transvaginal natural orifice transluminal endoscopic surgery–assisted living-donor nephrectomy in terms of feasibility and reproducibility.

Methods:

A total of 115 consecutive female patients who underwent laparoscopic living-donor nephrectomy (n = 70) or transvaginal natural orifice transluminal endoscopic surgery–assisted living-donor nephrectomy (n = 45) were included and compared in terms of operative characteristics, as well as donor and recipient outcomes.

Results:

No significant difference was observed between the laparoscopic living-donor nephrectomy and transvaginal natural orifice transluminal endoscopic surgery–assisted living-donor nephrectomy groups in terms of mean duration of warm and cold ischemia, operation time, length of hospital stay, arterial anastomoses, visual analog scale pain scores, serum creatinine levels, and receiver outcomes, whereas a significantly higher number of venous anastomoses was noted in the laparoscopic living-donor nephrectomy group than in the transvaginal natural orifice transluminal endoscopic surgery–assisted living-donor nephrectomy group (P = .029).

Conclusions:

Transvaginal natural orifice transluminal endoscopic surgery–assisted living-donor nephrectomy seems to be a feasible and reproducible alternative to conventional laparoscopic living-donor nephrectomy in female donors provided the viability of the vagina as an organ retrieval route.