Site Of Leak Research Articles

Targeted epidural blood patch through a catheter in the treatment of spontaneous intracranial hypotension.

ObjectiveSpontaneous intracranial hypotension (SIH) can be effectively treated by epidural blood patch (EBP) following the primary unsuccessful conservative therapy. Nevertheless, multi-site cerebrospinal fluid (CSF) leaks or those originating at the cervical or thoracic spine remain therapeutically challenging. Therefore, this study aimed to present our experience in the treatment of thoracic CSF leaks using epidural catheters for the EBP infusion. MethodsThree patients presenting with typical orthostatic headaches were qualified for an EBP procedure. Preoperative MRI scans, myelography, and CT myelography were performed. Additionally, delayed CT myelography was repeated after 3 h to identify the CSF leakage site. Patients were followed-up clinically and radiologically for three months. ResultsThe CT myelography identified CSF leak at the T2–3 (case 1), T5–12 (case 2), and T3–7 level (Case 3). A 0.06" diameter lumbar drainage catheter (Case 1 and 2) or Abbot's spinal cord stimulation (SCS) catheter (Case 3) was inserted epidurally through the lower thoracic/lumbar single-entry point and advanced into the identified thoracic leak site. The average volume of injected blood was 15.7 ml. No procedure-related complications were observed, and all patients improved clinically. ConclusionsEpidural catheters remain safe and effective in treating thoracic and multi-site CSF leaks. In addition, Abbot's SCS catheter was found superior to the lumbar drainage catheter due to higher rigidity and bigger diameter despite being shorter than the lumbar drainage catheter.

Efficacy of Navigated Laser Photocoagulation for Chronic Central Serous Chorioretinopathy: A Retrospective Observational Study.

Background. No consensus has been reached regarding the management of central serous chorioretinopathy (CSCR). We aimed to investigate the efficacy of navigated laser treatment for chronic CSCR and changes in the morphology of the retinal pigment epithelium (RPE). In this retrospective observational study, 19 patients with subjective symptoms admitted to the Nanjing Medical University Affiliated Eye Hospital were included between January 2021 and August 2021. All patients underwent visual acuity and optical coherence tomography (OCT) examination during follow-up. Fluorescein angiography (FA) was performed at baseline and at the final follow-up to confirm the dye leakage sites. The mean logMAR BCVA at baseline and at the end of follow-up was 0.49 ± 0.24 and 0.24 ± 0.15, respectively. The mean logMAR BCVA 3 months after treatment was significantly better than that before treatment (p = 0.002). Significant improvements were observed in central macular thickness (CMT) and subfoveal choroidal thickness (SFCT) after navigated laser photocoagulation (p < 0.0001). Subretinal fluid was completely resolved in 13 (68%) of 19 eyes at 3 months. RPE lesions on OCT images showed RPE detachment in 17 eyes (61.5%), small protrusion of the RPE layer in 5 eyes (7.5%), and a rough RPE layer in 4 eyes (31%). After laser treatment, 9 points (35%) showed retinal detachment, and 10 (38.5%) regions showed an irregular RPE layer. An irregularly protruded RPE layer was also observed in different regions of the leakage spot in 5 (19%) eyes, and RPE defects were seen in 2 (7.5%) eyes. Navigated laser photocoagulation for chronic CSCR can achieve substantial anatomical and visual improvement. OCT outcomes may provide new information to facilitate understanding of the mechanism of chronic CSCR. Navigated laser photocoagulation should be chosen as an optimal treatment option in patients with chronic CSCR who cannot afford photodynamic therapy.

Schlieren Phenomenon for Identification of Lymphorrhea Point.

Summary:Surgical invasion of the lymphatic system can lead to lymphorrhea. Lymphorrhea is first treated conservatively, but is often refractory and subsequently treated surgically. In surgery, it is difficult to identify the lymphatic leak points visually. In this study, we observed the schlieren phenomenon based on the difference in the refractive index between glucose solution and lymph fluid, and were able to easily identify the site of the lymphatic leakage in real time and treat lymphorrhea.

Simultaneous Integrated Boost Volumetric Modulated Arc Therapy for Rectal Cancer: Long-Term Results after Protocol-Based Treatment.

Background Volumetric modulated arc therapy (VMAT) with simultaneous integrated boost (SIB) is an advanced form of radiotherapy (RT) technology. The purpose of this study was to report long-term treatment outcomes in patients with locally advanced rectal cancer undergoing VMAT-SIB based concurrent chemoradiotherapy (CRT). Methods Between January 2016 and January 2018, a total of 22 patients with operable stage II-III rectal adenocarcinoma were recruited for the pre-designed VMAT-SIB RT protocol. All patients underwent standard diagnostic and staging work-up. The RT target volumes included the following areas: PTV1 = mesorectum that contained gross tumors and enlarged lymph node regions and PTV2 = mesorectum and regional lymphatics from L4-5/S1 to 3-4 cm below the tumor or levator ani muscle, excluding PTV1. The VMAT-SIB dose prescription was as follows: PTV1 = 52.5 Gy/daily 2.1 Gy/25 fractions, PTV2 = 45 Gy/daily 1.8 Gy/25 fractions. Results The mean age of the study population was 64 (range, 18-84) years, and 15 (68.2%) patients were male. Radical operation (total mesorectal excision) was performed by either low anterior resection, ultralow anterior resection, or abdominal perineal resection. All five (22.7%) of the patients with confirmed increasing serum carcinoembryonic antigen (CEA) level at diagnosis showed normalization of serum CEA level after the planned treatment. Among 20 patients who underwent preoperative CRT and surgery, tumor down staging in T- and N-stages was achieved in 10 patients (50%) and 13 patients (65%), respectively, with 20% of ypT0/Tis. With a median follow-up of 54.2 (range, 22.6-61.1) months, the 5-year disease-free survival, overall survival, and local control rates were 64.6%, 81.8%, and 84.4%, respectively. Five patients developed distant metastasis and one developed local recurrence as a first event. Two cases with anastomosis site leakage, three with adhesive ileus, and two with abscess formation were observed during postoperative periods. Conclusions The current VMAT-SIB-based CRT protocol provided acceptable treatment and toxicity outcomes.

Modern approaches to the diagnosis and treatment of spontaneous intracranial hypotension (a literature review)

The aim of this review is to analyze and summarize the existing evidence regarding the diagnosis and treatment of spontaneous intracranial hypotension. Spontaneous intracranial hypotension occurs due to a decrease in cerebrospinal fluid (CSF) volume as a result of its spontaneous leakage and has a variety of clinical and neuroimaging features, sometimes different from CSF hypotension after a lumbar puncture. Anatomical changes in spontaneous CSF leakage are complex and are often associated with structural disorders of the connective tissue, weakness of certain areas of the dura mater and its diverticulosis. One consequence of decreased CSF volume is brain descent. This leads to traction of pain-sensitive brain structures and, therefore, to headaches that are orthostatic or with some orthostatic features. The methods of choice to identify the site of CSF leak are CT-myelography and radioisotope cisternography. Epidural blood patch is the main treatment in most cases. Conclusions. The study on the most informative and minimally invasive methods to locate the site of CSF leak, conservative and surgical methods of treatment efficacy evaluation depending on the etiological factors of spontaneous intracranial hypotension are extremely important and promising scientific fields requiring further research with the development of personalized approaches considering the individual characteristics of each patient.

Biliopancreatic and biliary leak after pancreatoduodenectomy treated by percutaneous transhepatic biliary drainage.

Complementary to percutaneous intra-abdominal drainage, percutaneous transhepatic biliary drainage (PTBD) might ameliorate healing of pancreatic fistula and biliary leakage after pancreatoduodenectomy by diversion of bile from the site of leakage. This study evaluated technical and clinical outcomes of PTBD for this indication. All patients undergoing PTBD for leakage after pancreatoduodenectomy were retrospectively evaluated in two tertiary pancreatic centers (2014-2019). Technical success was defined as external biliary drainage. Clinical success was defined as discharge with a resolved leak, without additional surgical interventions for anastomotic leakage other than percutaneous intra-abdominal drainage. Following 822 pancreatoduodenectomies, 65 patients (8%) underwent PTBD. Indications were leakage of the pancreaticojejunostomy (n=25; 38%), hepaticojejunostomy (n=15; 23%) and of both (n=25; 38%). PTBD was technically successful in 64 patients (98%) with drain revision in 40 patients (63%). Clinical success occurred in 60 patients (94%). Leakage resolved after median 33 days (IQR 21-60). PTBD related complications occurred in 23 patients (35%), including cholangitis (n=14; 21%), hemobilia (n=7; 11%) and PTBD related bleeding requiring re-intervention (n=4; 6%). In hospital mortality was 3% (n=2). Although drain revisions and complications are common, PTBD is highly feasible and appears to be effective in the treatment of biliopancreatic leakage after pancreatoduodenectomy.

Risk factors and characteristics of central serous chorioretinopathy with later development of macular neovascularisation detected on OCT angiography: a retrospective multicentre observational study

ObjectiveTo identify the risk factors and characteristics of central serous chorioretinopathy (CSC) with subsequent macular neovascularisation (MNV) detected on optical coherence tomography angiography (OCTA).Methods and analysisWe included patients from six...

Establishing the National Institute for Research in Environmental Health, India.

ProblemMultiple environmental health issues resulting from pollution and climate change threaten public health in India.ApproachThe Government of India recognized the need for a permanent environmental health research institute; the Indian Council of Medical Research therefore established the National Institute for Research in Environmental Health in Bhopal in 2010. Scientists at the institute assessed the multiple long-term health effects of exposure to methyl isocyanate, and are now conducting research on a wide array of locally relevant environmental health issues.Local settingThe Union Carbide India Limited pesticide factory in Bhopal was the site of a methyl isocyanate gas leak in 1984, which affected half a million people. The Indian Council of Medical Research set up a coordinating unit in the immediate aftermath, which was upgraded to the Bhopal Gas Disaster Research Centre in 1986 and then the Centre for Rehabilitation Studies in 1995.Relevant changesScientists at the institute undertake environmental monitoring and health risk assessment studies among communities located near polluted areas, such as industrial areas. They are also assessing the training needs of practising physicians, with the aim of developing a curated curriculum to meet the deficiencies in environmental health education in the country.Lessons learntEnvironmental legislation was introduced in the wake of the disaster and a research institute in environmental health was established. Researchers at the institute have recognized the importance of engaging communities in environmental health research, as well as knowledge dissemination to relevant stakeholders.

Management options for Post Traumatic CSF Rhinorrhea

Objective: A descriptive case series study was aimed to evaluate management options for traumatic csf rhinorrhea and develop a better option&#x0D; Materials and Methods: The study was conducted at Neurosurgery department, Bahwal Victotoria hospital Bahawalpur . This study involved 80 patients aged between 20-55 years of both genders diagnosed of CSF rhinorrhea presented with trauma.&#x0D; Results: In the department of Neurosurgery BVH, Bahawalpur 2000 patients were admitted with head injury in two years from April 2021 to February 2022. A total of 80 patients of these had cerebrospinal fluid (CSF) rhinorrhea. This study was conducted to evaluate the management options of CSF rhinorrhea in the patients with head injury. CSF rhinorrhea was stopped in 70 patients with conservative management. In 10 patients cerebrospinal fluid rhinorrhea continued after the conservative management of 2-6 weeks and surgical repair of Dural tear at the base of skull was done in these patients. Site of CSF rhinorrhea leakage was located in these patients with the help of CT Scan and MRI skull.In all these patients Dural tears was repaired with a graft of fascia Lata or periosteum, pasted on the site of defect with fibrin glue.&#x0D; CONCLUSION:We concluded that all post traumatic C.S.F rhinorrhea cases should be managed conservatively because most of the C.S.F leaks stop spontaneously with proper conservative management. So surgical repair should be delayed for 2-12 weeks after a leak has been identified.

Regression patterns of central serous chorioretinopathy using en face optical coherence tomography

To study the regression patterns of subretinal fluid (SRF) in central serous chorioretinopathy (CSCR) on sequential en face optical coherence tomography (OCT) and its relationship to leak locations. Retrospective study on patients with acute CSCR. Inclusion criteria were (i) availability of data, sequential OCT and OCT angiography (B scan and en face OCT) every 2 weeks until resolution of SRF or 6 months, whichever is earlier; (ii) single active leak. Exclusion criteria were (i) presence of macular neovascularization or atypical CSCR, (ii) diffuse pigment epitheliopathy, (iii) multiple leaks. Serial en face OCT scans were evaluated and the area of SRF was measured using ImageJ software. Correlation coefficient was calculated for the regression rate of SRF area and central retinal thickness (CRT) over the first month of follow-up and the time of complete SRF resolution. Out of the 25 eyes, 20 eyes demonstrated a centripetal regression, and 5 eyes demonstrated a centrifugal regression. In eyes with a leakage point <1000μ from the fovea, 86% resolved in a centripetal fashion, and in eyes with leak site ≥1000μ away from fovea, 70% eyes resolved centripetally. There was a correlation (r=-0.47, p=0.018) of the rate regression of SRF area during the first month and timing of resolution. In contrast, this correlation was absent (r=-0.16, p=0.44) for CRT regression. Our en face-based analysis of sequential OCTs of regressing CSCR demonstrated a tendency for the subfoveal SRF to resolve towards the end or a centripetal pattern of regression. Prediction of resolution of SRF at 1 month is better with en face area of SRF in comparison to CRT.

Resectable Gastric Adenocarcinoma Cancer and the Role of Early Feeding on Clinical Outcome

&#x0D; Background: Gastric adenocarsinoma is one of the most common gastrointestinal tract cancer, it could be found either in elderly or young patients. Surgical resection is still the main therapeutic option and the gold standard for the resectable cases. Enhanced recovery protocols has been announced to improved the clinical outcome in of gastrointestinal cancer surgery. Especially in upper GI cancer, which still challenging in starting the oral feeding after surgical resection. We will reported the clincal outcome of early feeding on resectable gastric adenocarsinoma patients.&#x0D; &#x0D; &#x0D; &#x0D; &#x0D; &#x0D; Methods: This was a retrospective study, taken from January 2018 - December 2020. All resectable gastric adenocarsinoma patients were included. Tumor locations, type of resection and reconstruction were evaluated. All patients had early oral feeding from the first post operative day, continued with liquid and semi solid food. The short term outcome were recorded including the anastomose leakage and surgical site infection. &#x0D; &#x0D; &#x0D; &#x0D; &#x0D; &#x0D; Results: We reported eight gastric cancer patients during this study, 1 patient was young gastric cancer patiens and the rest were &gt; 50 years old patients. Gastric anthrum was the most common tumor site with partial gatrectomy and Billroth II have been done. 3 patients were corpus site and 1 case of fundus cancer, total gastrectomy and roux en y esófago-jejunostomy reconstruction was done. &#x0D; &#x0D; &#x0D; We found no anastomosis leakage. No SSI and no readmission associated with post operative morbidity. &#x0D; &#x0D; &#x0D; &#x0D; &#x0D; &#x0D; Conclusion: Early feeding on resectable gastric adenocarsinoma patients was feasibel, has good clinical outcomes and could tolerated well, no matter what type of gastric resection we did.&#x0D; &#x0D; &#x0D; &#x0D; &#x0D; &#x0D; &#x0D; &#x0D; &#x0D; &#x0D;

Congenital spontaneous otogenic cerebrospinal fluid leak as a cause of recurrent meningitis in a 9-year-old child – case report and literature review

&lt;b&gt;Introduction:&lt;/b&gt; Congenital otogenic CSF leak is a rare cause of meningitis. The underlying reason may be a defect of the fundus of internal auditory meatus with pathological communication with the inner ear and CSF leak to middle ear space. This condition requires surgical closure. &lt;/br&gt;&lt;/br&gt; &lt;b&gt;Case report:&lt;/b&gt; A 9-year-old boy with a history of recurrent meningitis – 3 episodes. During the last episode, β-2 transferrin test from ear fluid was positive. The patient complained of leakage of clear fluid through the nose on the right side. Otoscopy revealed a bulging tympanic membrane on the right side. The right ear was deaf with normal hearing on the left side. HRCT revealed congenital deformity of the right inner ear. Right side lateral petrosectomy with blind sac closure of the right external auditory canal was performed. During surgery there was an extensive CSF leak through the oval window niche due to a lack of the stapes footplate in the anterior part. Recovery was uneventful. After 24 months of follow up, no more leakage through the nose was observed. Control magnetic resonance performed one year after surgery showed no CSF in the mastoid cavity. &lt;/br&gt;&lt;/br&gt; &lt;b&gt;Discussion:&lt;/b&gt; Inner ear malformations are a rare cause of meningitis, and the most common sites of congenital otogenic CSF leakage include the oval and round window. Surgical closure is the only solution in such cases. Several methods of sealing the inner ear space were described in the literature. Vestibular packing and stapedectomy were most frequently used. However, recurrences were stated in up to 1/2 of cases. Such a risk can be limited with lateral petrosectomy. For this reason, LP can be considered as the treatment of choice in congenital spontaneous otogenic cerebrospinal fluid leak. &lt;/br&gt;&lt;/br&gt; &lt;b&gt;Conclusion:&lt;/b&gt; Every case of recurrent meningitis in children should be investigated with a suspicion of congenital ear malformation with spontaneous CSF leakage. Lateral petrosectomy is a safe and effective procedure for cases of otogenic CSF leak with a low risk of recurrence.

Mechanosensitive calcium flashes promote sustained RhoA activation during tight junction remodeling.

Epithelial cell-cell junctions remodel in response to mechanical stimuli to maintain barrier function. Previously, we found that local leaks in tight junctions (TJs) are rapidly repaired by local, transient RhoA activation, termed "Rho flares," but how Rho flares are regulated is unknown. Here, we discovered that intracellular calcium flashes and junction elongation are early events in the Rho flare pathway. Both laser-induced and naturally occurring TJ breaks lead to local calcium flashes at the site of leaks. Additionally, junction elongation induced by optogenetics increases Rho flare frequency, suggesting that Rho flares are mechanically triggered. Depletion of intracellular calcium or inhibition of mechanosensitive calcium channels (MSCs) reduces the amplitude of calcium flashes and diminishes the sustained activation of Rho flares. MSC-dependent calcium influx is necessary to maintain global barrier function by regulating reinforcement of local TJ proteins via junction contraction. In all, we uncovered a novel role for MSC-dependent calcium flashes in TJ remodeling, allowing epithelial cells to repair local leaks induced by mechanical stimuli.

Spinal Cerebrospinal Fluid Leak: Current Concepts and Management Policies

In this article we provide an update on the recent developments in understanding the diagnosis and treatment of spinal cerebrospinal fluid(CSF)leaks. Patients with spinal CSF leak show an increasingly broad spectrum of clinical presentations including intractable whiplash-associated disorder(WAD)and orthostatic dysregulation in childhood, in addition to classical spontaneous intracranial hypotension(SIH). A simple understanding of the condition defined by the presence of low CSF pressure is no longer sufficient or accurate. Fat-suppressed T2-weighted magnetic resonance images and continuous epidural fluid infusion as a diagnostic therapy ensure accurate diagnosis. Accurate localization of the leak followed by targeted epidural blood patch(EBP)significantly improves the outcome of patients with spinal CSF leak. In addition to the known sites of CSF leakage, a newly identified CSF leak site, at the craniovertebral junction dural entry point of the vertebral artery(VA), is described.

Early enteral feeding in patients with gastrointestinal surgery time to send the patient home early

Background: There has been a trend among surgeons to delay enteral feeding following gastrointestinal surgery so that complications like anastomotic site leak and infection can be prevented and also to give time for operated site to heal. Newer studies suggest that early enteral feeding is useful in comparison to conventional method of feeding i.e. waiting for bowel function to return. This study was undertaken to evaluate the safety and tolerability of early enteral feeding after gastrointestinal surgeries in terms of postoperative complications and length of hospitalization.Methods: This study was prospective observational study with retrospective controls done over a period of 18 months at a tertiary care center in India. 35 patients were included in each group (case versus control). Early enteral feeding was defined as commencement of oral feed within 48 hours of surgery. The data was analyzed using statistical package of social science (SPSS Version 20; Chicago Inc., USA).Results: Both groups were found to be well matched in terms of age and sex distribution. The mean hospital stay for patients given early enteral feeding was significantly lower as compared to controls (10.26±3.09 versus 13.4±2.186). They had a complication rate of 11.4 % as compared to late enteral feeding group (25.7%).Conclusions: Early enteral feeding has been found beneficial in most of the studies worldwide. Hence, it is time to open our minds and embrace it to improve surgical outcome in gastrointestinal surgery practice.

Influence of Preoperative Nutritional Status on Patients Who Undergo Upfront Surgery for Esophageal Squamous Cell Carcinoma

Few studies have focused on preoperative nutritional status of esophageal cancer patients eligible for upfront surgery. We aimed to investigate the association of preoperative nutritional status with prognosis of patients who undergo upfront surgery for esophageal cancer. A total of 274 patients who underwent upfront surgery for esophageal squamous cell carcinoma between January 2012 and December 2016 were eligible. Preoperative nutritional status was evaluated using prognostic nutritional index (PNI) scoring system, nutritional risk screening 2002 (NRS 2002), and controlling nutritional status. The median age was 63 years (interquartile range, 58–70) and 94.7% of patients were male. The pathological stages were Stage I—74.5% (204/274), Stage II—20.4% (56/274), and Stage III—5.1% (14/274). Multivariate analysis revealed that advanced stage, a low PNI, and a high NRS 2002 were independent predictors of overall survival. During median follow-up period of 55 mo, overall survival rates were lower in the high NRS 2002 group (P < 0.001). A high NRS 2002 score was associated with frequent postoperative complications, especially pneumonia and anastomosis site leakage (P = 0.003). The poor preoperative nutritional status with a high NRS 2002 is associated with postoperative complications as well as poor overall survival in patients with upfront surgery for esophageal cancer. Supplemental data for this article is available online at https://doi.org/10.1080/01635581.2022.2042573

Ligature Technique: A Safe Outcome in Laparoscopic Cholecystectomy

Objective: To compare Extracorporeal Sliding knot (ECK) and clip ligation to ligation of the cystic duct in laparoscopic cholecystectomy. Patients and Methods: This study was conducted as prospective randomized study in Jeddah National Hospital in Jeddah Saudi Arabia, in surgical department carried out from June 2018 to June 2019. In the study 100 patients were selected and divided into two groups, in which we compared outcomes of patients in whom Cystic Duct Occlusion was done by clips (Group I n=60) and other group Ligatures endoloop knotting (Group II n=40). During laparoscopic cholecystectomy (LC), cystic duct occlusion can be done with titanium clips or ligature permanently in order to prevent leakage of bile into the peritoneal cavity. Results: Average age of the patients of clipping group was 43.68 years and the average age of the patients of knot group was 42.64 years, with male to female ration as 1:4.5. 1:2.3 of clipping and knot group respectively. Regarding operating time from initial incision to closure of wound is 61 to 65 minutes in clip group and 69 to 70 minutes in knot group. Longer operating times in knot group is due to learning curve effect for most surgeons as is evident from the fact that first twenty surgeries took longer time as compared to subsequent surgeries. The port site infection was in 03 cases of the clip group 01 in the knot group, drain was kept in 12 cases in knot group and 06 in clip group, bile leak requiring ERCP 02 cases in clip group and 01 in knot group, retained CBD Stones 01 was in clip group, obstructive Jaundice was seen in one cases of clip group, while no mortality was seen in both groups. Although the hospital stay after surgery in clip group was 1-2 days and in knot group also 1-2 days and in ERCP patients’ Hospital stay was 2 to 3 days. Conclusion: Cystic duct occlusion with knots/ligatures is a safe, cost effective, less post operative pain alternative to clips as various studies showed clips complications. It also showed less post-operative pain, less bile leak and port site wound infection. Safety of using knots/ligatures is even better than clips as is evident from this study comparing these two methods of cystic duct occlusion. Key words: cholecystectomy, surgical clips, surgical knots, surgical ligature, cystic duct occlusion, bile leakage

SmartPAN: In vitro and in vivo proof-of-safety assessments for an intra-operative predictive indicator of postoperative pancreatic fistula.

Pancreatic surgery is complicated by untreated fluid leakage, but no tenable techniques exist to detect and close leakage sites during surgery. A novel hydrogel called SmartPAN has been developed to meet this need and is here assessed for safety before trials on human patients. First, resazurin assays were used to test the cytotoxic effects of SmartPAN's active bromothymol blue (BTB) indicator and its solution of phosphate-buffered saline (PBS) on normal (HPDE: human pancreatic duct epithelial) or carcinomic (FAMPAC) human pancreatic cells. Cells incubated with BTB showed no significant reduction in cell viability below threshold safety levels. However, PBS had a mild cytotoxic effect on FAMPAC cells. Second, SmartPAN's pathological effects were evaluated in vivo by applying 4-ml SmartPAN to a porcine (Sus scrofa domesticus) model of pancreatic resection. There were no significant differences in macroscopic and microscopic pathologies between pigs treated with SmartPAN or saline. Third, measurements using HPLC-MS/MS demonstrate that BTB does not cross into the bloodstream and was eliminated from the body within 2days of surgery. Overall, SmartPAN appears safe in the short term and ready for first-in-human trials because its components are either biocompatible or quickly neutralized by dilution and drainage.

Identification of type of threading dislocation causing reverse leakage in GaN p\u2013n junctions after continuous forward current stress

Power devices are operated under harsh conditions, such as high currents and voltages, and so degradation of these devices is an important issue. Our group previously found significant increases in reverse leakage current after applying continuous forward current stress to GaN p–n junctions. In the present study, we identified the type of threading dislocations that provide pathways for this reverse leakage current. GaN p–n diodes were grown by metalorganic vapor phase epitaxy on freestanding GaN(0001) substrates with threading dislocation densities of approximately 3 × 105 cm−2. These diodes exhibited a breakdown voltage on the order of 200 V and avalanche capability. The leakage current in some diodes in response to a reverse bias was found to rapidly increase with continuous forward current injection, and leakage sites were identified by optical emission microscopy. Closed-core threading screw dislocations (TSDs) were found at five emission spots based on cross-sectional transmission electron microscopy analyses using two-beam diffraction conditions. The Burgers vectors of these dislocations were identified as [0001] using large-angle convergent-beam electron diffraction. Thus, TSDs for which b = 1c are believed to provide current leakage paths in response to forward current stress.

Efficacy and Role of Intrathecal Fluorescein for Detection of Defect Site for Treatment of Cerebrospinal Fluid Rhinorrhea

Background/Objectives: Cerebrospinal fluid (CSF) rhinorrhea is a rare but potentially devastating condition that can lead to significant mortality and morbidity. 90% of post-traumatic rhinorrheas stop conservatively, 10% of post-traumatic, spontaneous, and post-operative rhinorrhea need surgical repair. Fluorescein is helpful in the detection of CSF rhinorrhea peroperatively.&#x0D; Material and Methods: A descriptive case series was conducted at the Department of Neurosurgery, PINS Lahore in a single unit by a single surgical team. 62 patients were enrolled who met the inclusion and exclusion criteria. The lumbar drain was passed at L4 – L5 level and 0.1 ml of 25% sodium Fluorescein was diluted in 10 ml of CSF. The endoscope passed through the nostril and the leakage point was detected by yellowish-green fluid coming out of the rent under endoscope. After surgery, the patients were followed up after two weeks to observe the efficacy. Post-stratification was done through a chi-square test.&#x0D; Results: The mean age of the patients was 42.85 years. The most common leakage was found from cribriform plate followed by lateral lamella &amp; sphenoid sinus. Gender difference, leakage site, and age of the patients did not have significant effects on the results of using fluorescein dye for detecting the rent. The benefit of using the dye was 79%.&#x0D; Conclusion: This study indicated that intrathecal fluorescein is a highly effective and beneficial approach for pinpoint localization of CSF defect, particularly very minute defects, and plays an important role in the successful treatment of CSF rhinorrhea.