Descemet membrane detachment after nonpenetrating filtering surgery.

PURPOSE: To make surgeons performing nonpenetrating filtering surgery aware of an unusual complication namely Descemet membrane detachment. METHODS: We retrospectively reviewed nine eyes of nine patients seen in our hospital with Descemet membrane detachment occurring after nonpenetrating filtering surgery from January 1994 to December 2000. RESULTS: Both planar and nonplanar detachments were reported. Neither scrolls nor tears in the Descemet membrane were observed in any patient. After viscocanalostomy (four patients), the detachment was generally noticed shortly after the procedure and the cornea maintained its clarity. After deep sclerectomy with a collagen implant (five patients), it developed weeks to months postoperatively with adjacent corneal edema. Four patients had descemetopexy. None required more than one procedure. However, at the last visit, two detachments persisted although they had diminished in size: one after viscocanalostomy and conservative treatment and one after descemetopexy after deep sclerectomy with a collagen implant. To date otherwise, no signs of significant corneal damage could be observed clinically nor by specular microscopy and pachymetry. CONCLUSIONS: The diagnosis of Descemet membrane detachment can be easily overlooked or misdiagnosed. The clinical presentation, clinical course, and pathogenesis depend on the type of nonpenetrating filtering surgery performed. Ophthalmologists should be aware of this unusual complication, which is likely to be more common after nonpenetrating filtering surgery than after trabeculectomy. A period of observation before attempting descemetopexy is recommended.

Surgery for incarcerated hernia: short-term outcome with or without mesh.

BACKGROUND: Incarcerated hernias represent about 5-15 % of all operated hernias. Tension-free mesh is the preferred technique for elective surgery due to low recurrence rates. There is however currently no consensus on the use of mesh for the treatment of incarcerated hernias, especially in case of bowel resection. AIM: The aims of this study were (i) to report our current practice for the treatment of incarcerated hernias, (ii) to identify risk factors for postoperative complications, and (iii) to assess the safety of mesh placement in potentially infected surgical fields. METHODS: This retrospective study included 166 consecutive patients who underwent emergency surgery for incarcerated hernia between January 2007 and January 2012 in two university hospitals. Demographics, surgical details, and short-term outcome were collected. Univariate analysis was employed to identify risk factors for overall, infectious, and major complications. RESULTS: Eighty-four patients (50.6 %) presented inguinal hernias, 43 femoral (25.9 %), 37 umbilical hernias (22.3 %), and 2 mixed hernias (1.2 %), respectively. Mesh was placed in 64 patients (38.5 %), including 5 patients with concomitant bowel resection. Overall morbidity occurred in 56 patients (32.7 %), and 8 patients (4.8 %) developed surgical site infections (SSI). Univariate risk factors for overall complications were ASA grade 3/4 (P = 0.03), diabetes (P = 0.05), cardiopathy (P = 0.001), aspirin use (P = 0.023), and bowel resection (P = 0.001) which was also the only identified risk factor for SSI (P = 0.03). In multivariate analysis, only bowel incarceration was associated with a higher rate of major morbidity (OR = 14.04; P = 0.01). CONCLUSION: Morbidity after surgery for incarcerated hernia remains high and depends on comorbidities and surgical presentation. The use of mesh could become current practice even in case of bowel resection.

Cerebral metabolic effects of exogenous lactate supplementation on the injured human brain.

PURPOSE: Experimental evidence suggests that lactate is neuroprotective after acute brain injury; however, data in humans are lacking. We examined whether exogenous lactate supplementation improves cerebral energy metabolism in humans with traumatic brain injury (TBI). METHODS: We prospectively studied 15 consecutive patients with severe TBI monitored with cerebral microdialysis (CMD), brain tissue PO2 (PbtO2), and intracranial pressure (ICP). Intervention consisted of a 3-h intravenous infusion of hypertonic sodium lactate (aiming to increase systemic lactate to ca. 5 mmol/L), administered in the early phase following TBI. We examined the effect of sodium lactate on neurochemistry (CMD lactate, pyruvate, glucose, and glutamate), PbtO2, and ICP. RESULTS: Treatment was started on average 33 ± 16 h after TBI. A mixed-effects multilevel regression model revealed that sodium lactate therapy was associated with a significant increase in CMD concentrations of lactate [coefficient 0.47 mmol/L, 95% confidence interval (CI) 0.31-0.63 mmol/L], pyruvate [13.1 (8.78-17.4) μmol/L], and glucose [0.1 (0.04-0.16) mmol/L; all p < 0.01]. A concomitant reduction of CMD glutamate [-0.95 (-1.94 to 0.06) mmol/L, p = 0.06] and ICP [-0.86 (-1.47 to -0.24) mmHg, p < 0.01] was also observed. CONCLUSIONS: Exogenous supplemental lactate can be utilized aerobically as a preferential energy substrate by the injured human brain, with sparing of cerebral glucose. Increased availability of cerebral extracellular pyruvate and glucose, coupled with a reduction of brain glutamate and ICP, suggests that hypertonic lactate therapy has beneficial cerebral metabolic and hemodynamic effects after TBI.

The pressure cooker technique for the treatment of brain AVMs.

Arteriovenous malformations (AVMs) may be cured by injecting liquid embolic agents such as Onyx. Reflux, however, can sometimes be difficult to control and may jeopardize a complete embolization. The pressure cooker technique (PCT) was designed to create an anti-reflux plug by trapping the detachable part of an Onyx-compatible microcatheter with coils and glue in order to obtain wedge-flow conditions, thereby enabling a better understanding of macrofistulous AVMs and a more comprehensive, forceful and controlled Onyx embolization. The PCT might enlarge the range of AVMs amenable to endovascular cure. Three illustrative cases are presented.

Consensus guidelines for enhanced recovery after gastrectomy: Enhanced Recovery After Surgery (ERAS®) Society recommendations.

BACKGROUND: Application of evidence-based perioperative care protocols reduces complication rates, accelerates recovery and shortens hospital stay. Presently, there are no comprehensive guidelines for perioperative care for gastrectomy. METHODS: An international working group within the Enhanced Recovery After Surgery (ERAS®) Society assembled an evidence-based comprehensive framework for optimal perioperative care for patients undergoing gastrectomy. Data were retrieved from standard databases and personal archives. Evidence and recommendations were classified according to the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system and were discussed until consensus was reached within the group. The quality of evidence was rated 'high', 'moderate', 'low' or 'very low'. Recommendations were graded as 'strong' or 'weak'. RESULTS: The available evidence has been summarized and recommendations are given for 25 items, eight of which contain procedure-specific evidence. The quality of evidence varies substantially and further research is needed for many issues to improve the strength of evidence and grade of recommendations. CONCLUSION: The present evidence-based framework provides comprehensive advice on optimal perioperative care for the patient undergoing gastrectomy and facilitates multi-institutional prospective cohort registries and adequately powered randomized trials for further research.

Malignant glioma after ependymoma: an unusual secondary malignancy

Purpose : Secondary malignancies (SM) are a known long-­‐term problem in children surviving brain tumors. We report on two unusual cases of SM observed after treatment of ependymoma. Case reports : 1. The first case is a female survivor of a low-­‐grade ependymoma (Grade II). She had been treated at the age of 3 months with surgery and chemotherapy. A relapse of the primary tumor happened two years later, which was completely removed and treated with local radiotherapy to the posterior fossa. Fifteen years after the first cancer, she developed a pontine glioma near the location of the previous radiotherapy. 2. The second case is a femal survivor of an ependymoma (Grade III) which was removed and irradiated when she was 4 years old. The child developed a pontine glioma near the location of the previous radiotherapy ten years after the diagnosis of the first cancer. Further extension of the disease showed after biopsy PNET-­‐ like features. Both patients passed away. Discussion and Conclusion : Second malignant neoplasia is a rare phenomenon and this risk should not overshadow the great success in treating cancer of childhood. Among the studied risk factors, young age and radiotherapy are well established. The reported patients were followed annually to ensure their remission and both developed symptoms and an unusual unreported secondary cancer a few months after the annual monitoring that was considered as normal. This issue highlights the complexity of monitoring cancer survivors and raises the question of the best way for their long-­‐term follow-­‐up.

Bosentan and/or Sildenafil for non-operable chronic thromboembolic pulmonary hypertension

Objectives: To evaluate outcome of patients treated "off-label" by bosentan and/or sildenafil for chronic thromboembolic pulmonary hypertension (CTEPH). Patients and methods: Since 2003, 18 patients (mean age 69 ± 11 years) have been treated with bosentan and/or sildenafil for CTEPH (mean pulmonary arterial resistance 8.1 ± 3.7 U Wood) in Lausanne University Hospital, with a follow-up of at least 12 months. Sixteen of them were inoperable because of distal disease and/or age or significant co-morbidities and 2 had persistent or recurrent pulmonary hypertension despite surgery. Efficacy of treatment was evaluated by comparison of New York Heart Association functional class (NYHA), six-minute walk test (6-MWT) and serum levels of N-terminal-pro brain natriuretic peptide (NT pro-BNP) at baseline (T0) and at 12 months (T12). Wilcoxon rank test was used for statistics. Results: At T0, median NYHA class was III (range II-IV), 6-MWT was 348 meters (5 and 95 centiles:0, 539) and NT pro-BNP was 387 mmol/l (58, 3508). At T12, 11 patients were treated with bosentan, 5 with sildenafil, 1 with inhaled Iloprost (because of failure of the two other treatments) and 1 with a combination of sildenafil and Iloprost. NYHA had improved in 10 patients, remained stable in 7 and worsened in 1 (median decrease 0.5 (-2; 0.2) p = 0.013). Six-MWT improved by a median of 15 meters (-142, +270) (p = 0.047) and NT pro-BNP decreased by a median of 65 mmol/l (-2988, +187) (p = n.s.). Among the 10 patients with a follow-up of 2 years or longer, two thirds remained stable and one third had worsened at 24 month. Treatments were well tolerated and only one patient had significant side effects (cutaneous reaction to bosentan) necessitating a switch to another treatment. Conclusion: In agreement with published data, bosentan and sildenafil improved functional status (NYHA, 6-MWT) and haemodynamics (NT pro BNP) in our patients with inoperable CTEPH. However these medications should not be used as substitute for surgery when the latter is applicable.

A fast-track program reduces complications and length of hospital stay after open colonic surgery.

BACKGROUND & AIMS: A fast-track program is a multimodal approach for patients undergoing colonic surgery that combines stringent regimens of perioperative care (fluid restriction, optimized analgesia, forced mobilization, and early oral feeding) to reduce perioperative morbidity, hospital stay, and cost. We investigated the impact of a fast-track protocol on postoperative morbidity in patients after open colonic surgery. METHODS: A randomized trial of patients in 4 teaching hospitals in Switzerland included 156 patients undergoing elective open colonic surgery who were assigned to either a fast-track program or standard care. The primary end point was the 30-day complication rate. Secondary end points were severity of complications, hospital stay, and compliance with the fast-track protocol. RESULTS: The fast-track protocol significantly decreased the number of complications (16 of 76 in the fast-track group vs 37 of 75 in the standard care group; P = .0014), resulting in shorter hospital stays (median, 5 days; range, 2-30 vs 9 days, respectively; range, 6-30; P < .0001). There was a trend toward less severe complications in the fast-track group. A multiple logistic regression analysis revealed fluid administration greater than the restriction limits (odds ratio, 4.198; 95% confidence interval, 1.7-10.366; P = .002) and a nonfunctioning epidural analgesia (odds ratio, 3.365; 95% confidence interval, 1.367-8.283; P = .008) as independent predictors of postoperative complications. CONCLUSIONS: The fast-track program reduces the rate of postoperative complications and length of hospital stay and should be considered as standard care. Fluid restriction and an effective epidural analgesia are the key factors that determine outcome of the fast-track program.

Time processing in visual cortices: How the visual brain encodes and keeps track of time

Time is embedded in any sensory experience: the movements of a dance, the rhythm of a piece of music, the words of a speaker are all examples of temporally structured sensory events. In humans, if and how visual cortices perform temporal processing remains unclear. Here we show that both primary visual cortex (V1) and extrastriate area V5/MT are causally involved in encoding and keeping time in memory and that this involvement is independent from low-level visual processing. Most importantly we demonstrate that V1 and V5/MT are functionally linked and temporally synchronized during time encoding whereas they are functionally independent and operate serially (V1 followed by V5/MT) while maintaining temporal information in working memory. These data challenge the traditional view of V1 and V5/MT as visuo-spatial features detectors and highlight the functional contribution and the temporal dynamics of these brain regions in the processing of time in millisecond range. The present project resulted in the paper entitled: 'How the visual brain encodes and keeps track of time' by Paolo Salvioni, Lysiann Kalmbach, Micah Murray and Domenica Bueti that is now submitted for publication to the Journal of Neuroscience.

Predictive value of Glasgow Coma Scale after brain trauma: change in trend over the past ten years.

BACKGROUND: Age and the Glasgow Coma Scale (GCS) score on admission are considered important predictors of outcome after traumatic brain injury. We investigated the predictive value of the GCS in a large group of patients whose computerised multimodal bedside monitoring data had been collected over the previous 10 years. METHODS: Data from 358 subjects with head injury, collected between 1992 and 2001, were analysed retrospectively. Patients were grouped according to year of admission. Glasgow Outcome Scores (GOS) were determined at six months. Spearman's correlation coefficients between GCS and GOS scores were calculated for each year. RESULTS: On average 34 (SD: 7) patients were monitored every year. We found a significant correlation between the GCS and GOS for the first five years (overall 1992-1996: r = 0.41; p<0.00001; n = 183) and consistent lack of correlations from 1997 onwards (overall 1997-2001: r = 0.091; p = 0.226; n = 175). In contrast, correlations between age and GOS were in both time periods significant and similar (r = -0.24 v r = -0.24; p<0.002). CONCLUSIONS: The admission GCS lost its predictive value for outcome in this group of patients from 1997 onwards. The predictive value of the GCS should be carefully reconsidered when building prognostic models incorporating multimodality monitoring after head injury.

Peroxisome proliferator-activated receptor-alpha-null mice have increased white adipose tissue glucose utilization, GLUT4, and fat mass: Role in liver and brain.

Activation of the peroxisome proliferator-activated receptor (PPAR)-alpha increases lipid catabolism and lowers the concentration of circulating lipid, but its role in the control of glucose metabolism is not as clearly established. Here we compared PPARalpha knockout mice with wild type and confirmed that the former developed hypoglycemia during fasting. This was associated with only a slight increase in insulin sensitivity but a dramatic increase in whole-body and adipose tissue glucose use rates in the fasting state. The white sc and visceral fat depots were larger due to an increase in the size and number of adipocytes, and their level of GLUT4 expression was higher and no longer regulated by the fed-to-fast transition. To evaluate whether these adipocyte deregulations were secondary to the absence of PPARalpha from liver, we reexpresssed this transcription factor in the liver of knockout mice using recombinant adenoviruses. Whereas more than 90% of the hepatocytes were infected and PPARalpha expression was restored to normal levels, the whole-body glucose use rate remained elevated. Next, to evaluate whether brain PPARalpha could affect glucose homeostasis, we activated brain PPARalpha in wild-type mice by infusing WY14643 into the lateral ventricle and showed that whole-body glucose use was reduced. Hence, our data show that PPARalpha is involved in the regulation of glucose homeostasis, insulin sensitivity, fat accumulation, and adipose tissue glucose use by a mechanism that does not require PPARalpha expression in the liver. By contrast, activation of PPARalpha in the brain stimulates peripheral glucose use. This suggests that the alteration in adipocyte glucose metabolism in the knockout mice may result from the absence of PPARalpha in the brain.

Postoperative epidural hematoma contributes to delayed upper cord tethering after decompression of Chiari malformation type I.

Symptomatic arachnoiditis after posterior fossa surgical procedures such as decompression of Chiari malformation is a possible complication. Clinical presentation is generally insidious and delayed by months or years. It causes disturbances in the normal flow of cerebrospinal fluid and enlargement of a syrinx cavity in the upper spinal cord. Surgical de-tethering has favorable results with progressive collapse of the syrinx and relief of the associated symptoms. Case Description: A 30-year-old male with Chiari malformation type I was treated by performing posterior fossa bone decompression, dura opening and closure with a suturable bovine pericardium dural graft. Postoperative period was uneventful until the fifth day in which the patient suffered intense headache and progressive loose of consciousness caused by an acute posterior fossa epidural hematoma. It was quickly removed with complete clinical recovering. One year later, the patient experienced progressive worsened of his symptoms. Upper spinal cord tethering was diagnosed and a new surgery for debridement was required. Conclusions: The epidural hematoma compressing the dural graft against the neural structures contributes to the upper spinal cord tethering and represents a nondescribed cause of postoperative fibrosis, adhesion formation, and subsequent recurrent hindbrain compression.

Hypothermie thérapeutique en traumatologie crânienne grave [Therapeutic hypothermia for severe traumatic brain injury].

Therapeutic hypothermia (TH) is considered a standard of care in the post-resuscitation phase of cardiac arrest. In experimental models of traumatic brain injury (TBI), TH was found to have neuroprotective properties. However, TH failed to demonstrate beneficial effects on neurological outcome in patients with TBI. The absence of benefits of TH uniformly applied in TBI patients should not question the use of TH as a second-tier therapy to treat elevated intracranial pressure. The management of all the practical aspects of TH is a key factor to avoid side effects and to optimize the potential benefit of TH in the treatment of intracranial hypertension. Induction of TH can be achieved with external surface cooling or with intra-vascular devices. The therapeutic target should be set at a 35°C using brain temperature as reference, and should be maintained at least during 48 hours and ideally over the entire period of elevated intracranial pressure. The control of the rewarming phase is crucial to avoid temperature overshooting and should not exceed 1°C/day. Besides its use in the management of intracranial hypertension, therapeutic cooling is also essential to treat hyperthermia in brain-injured patients. In this review, we will discuss the benefit-risk balance and practical aspects of therapeutic temperature management in TBI patients.