Extra-Arachnoidal Dissection and Limited Meatal Drilling for Excision of Giant Vestibular Schwannomas: Improved Facial Nerve Preservation.

Background: Surgical excision of giant (>4 cm size) vestibular schwannomas (VS) with preservation of facial nerve (FN) function remains a challenge. Objective: Our surgical technique using an extra-arachnoid plane of dissection and limited meatal drilling is described with the goal of improving FN preservation. Methods: Surgical results with respect to FN preservation were analyzed for two groups of giant VS patients: Group A-operated between 2002 and 2009 using "standard" surgical technique, group B-operated between 2009 and 2016 using extra-arachnoidal dissection and limited meatal drilling. All patients had a minimum follow-up of 1 year. Results: Group A: Of the 115 patients, total excision was possible in 103 (89.5%), near-total in 7 (6%), and subtotal in 5 (4.3%) patients. At a >6-month follow-up, 68 (59.1%) patients had good FN function (House-Brackmann [H&B] grades 1-2), while 21 (18.3%) patients had poor function (H&B grade 3-5). Grade 6 involvement was seen in 26 (22.6%). Five patients had lower cranial nerve impairment necessitating tracheostomy. Group B: Of the 98 patients, total excision was achieved in 70 (71.4%) patients, near-total in 9 (9.2%), and subtotal in 19 (19.4%). Four patients had repeat surgery; 14 underwent gamma-knife radiosurgery. At >6-month follow-up, 78 (79.5%) patients had good FN function (H&B grades 1-2), while 20 (20.4%) had poor function (H&B grade 3-5). Conclusions: With our 'modified' surgical technique of extra-arachnoidal dissection of VS throughout surgery and limited meatal drilling, an improved rate of functional FN preservation was observed.

Simplifying Tumor Volume Estimation from Linear Dimensions for Intra-Cranial Lesions Treated with Stereotactic Radiosurgery.

AIMS: This study aims to derive simple yet robust formula(s) for the calculation of cranial tumor volume using linear tumor dimensions in anterioposterior (AP), mediolateral (ML) and craniocaudal (CC) directions and also propose a reproducible methodology for tumor dimension measurements. MATERIALS AND METHODS: Magnetic resonance images (MRI) of 337 patients planned for Gammaknife Stereotactic Radiosurgery for different types of brain tumors were analyzed using Leksell Gamma Plan (LGP) software. Tumor volume in three dimensional was outlined and maximum tumor diameters were measured in three orthogonal directions AP, ML, and CC on the MRI. Formulas were derived to calculate tumor volume from AP, ML, and CC diameters using linear regression technique. An agreement between the calculated volume and standard volume observed from LGP software was determined using Bland Altman (B-A) plot. A comparison was made between the volume calculated using traditionally used formula of ellipsoid, standard volume obtained from LGP software and volume calculated from formulas derived in the present study. RESULTS: The tumors were divided into two categories based on their size for better volume prediction. The tumors having product of their diameters in the range 0-2.5cc were called "small tumors" and the formula proposed for their volume estimation (V = 1.513) × (AP × ML × CC) + 0.047 ) was found to predict the tumor volume with an average bias of 0.0005cc. For "large tumors," having product of diameters in the range 2.5-36cc, the proposed formula (V = 0.444 × (AP × ML × CC) + 0.339 ) predicted the tumor volume with an average bias of 0.007cc. CONCLUSIONS: The two formulas proposed in the study are more accurate as compared to the commonly used formula that considers the tumors as ellipsoids. The methodology proposed in the study for measurement of linear tumor dimensions is simple and reproducible.

Tungiasis: Outbreak investigation of a zoonosis during overseas deployment.

BACKGROUND: Tungiasis is an ectoparasitosis caused by the sand flea Tunga penetrans. It is endemic in the under privileged communities of Latin America, the Caribbean and Sub Saharan Africa with geographic and seasonal variations even within endemic areas. We describe investigation of an outbreak of Tungiasis in troops deployed as part of UN peacekeeping force in Central Africa. METHODS: Tungiasis was diagnosed in an unusually large number of cases of severely pruritic boils over feet in soldiers of a UN peacekeeping battalion. An outbreak investigation was carried out and the outbreak was described in time, place and person distribution. A retrospective cohort study was done to ascertain the associated risk factors. RESULTS: A total of 36 cases were identified of which 33 had laboratory confirmation. Of the 36 cases, 10(27.77%) had only Fortaleza Stage II lesions, 22 (61.11%) a combination of Fortaleza Stage II and III lesions and four (11.11%) cases had a combination of Stage, II, III and IV lesions. Secondary bacterial infection was seen in 25 (69.44%) cases. Epidemiological analysis revealed that it was a common source single exposure outbreak traced to a temporary campsite along one of the patrolling routes. CONCLUSION: In a Military setting an integrated approach combining health education and environmental control is required to prevent such outbreaks.

A novel multimodal chromatography based single step purification process for efficient manufacturing of an E. coli based biotherapeutic protein product.

Methionine oxidized, reduced and fMet forms of a native recombinant protein product are often the critical product variants which are associated with proteins expressed as bacterial inclusion bodies in E. coli. Such product variants differ from native protein in their structural and functional aspects, and may lead to loss of biological activity and immunogenic response in patients. This investigation focuses on evaluation of multimodal chromatography for selective removal of these product variants using recombinant human granulocyte colony stimulating factor (GCSF) as the model protein. Unique selectivity in separation of closely related product variants was obtained using combined pH and salt based elution gradients in hydrophobic charge induction chromatography. Simultaneous removal of process related impurities was also achieved in flow-through leading to single step purification process for the GCSF. Results indicate that the product recovery of up to 90.0% can be obtained with purity levels of greater than 99.0%. Binding the target protein at pH

A novel aqueous two phase assisted platform for efficient removal of process related impurities associated with E. coli based biotherapeutic protein products.

This article presents a variant of aqueous two phase system (ATPS) as a tool for selective removal of process related impurities associated with Escherichia coli, namely host cell proteins and nucleic acids. Granulocyte colony stimulating factor (GCSF) expressed in E. coli has been selected as a model protein for the study. While achieving effective removal of host cell impurities as per the regulatory requirement for recombinant therapeutics, high product recovery has been achieved by adopting a novel strategy involving resolubilization of interfacial GCSF precipitate. This has been done such that the structural and biological activity of the product is retained. Exhaustive analysis of structural as well as functional integrity of resolubilized GCSF has been carried out using advanced analytical and in vitro bioassay tools. Product recovery of 99.5% has been achieved with the concentration of host cell proteins less than 100ppm and of nucleic acids below 10ng/ml. We think that the proposed platform can enable use of ATPS as a more economical alternative to process chromatography in industrial biopharmaceutical manufacturing processes.

Stapled hemorrhoidopexy - Initial experience from a general surgery center.

BACKGROUND: Stapled hemorrhoidopexy is gaining popularity as a relatively painless alternative to conventional excisional hemorrhoidectomy. The initial experience from a service hospital is presented along with review of literature. METHODS: 40 cases were managed by stapled hemorrhoidopexy (SH) over a period of two and half years. The primary outcome measures assessed were the analgesic requirement in the post-operative period and the time taken to resume Activities of Daily Living (ADL). Additional outcome measures studied were; presence of bleeding per rectum, prolapse of mass per rectum, incontinence to flatus/stool, post-operative urinary retention, requirement of a repeat procedure, presence of post-operative anal stenosis, and residual external haemorrhoids at 1 week, 1, 3 and 6 months and 1 year after surgery. RESULTS: 40 patients with grade II, III and IV hemorrhoids underwent SH under spinal anesthesia. In the first 24 h 17 patients required a single dose of Injection Diclofenac Sodium while 19 patients required two doses and 4 patients had to be given three doses. 14 patients (35%) achieved Katz Index of Independence in Activities of Daily Living score of 6 on the first post-operative day and another 17 (42.5%) on the second post-operative day. By the fourth post-operative day all patients had achieved a score of 6. One patient had a rectal perforation as a complication of the procedure and another required a second procedure for excision of thrombosed external hemorrhoids. CONCLUSION: Stapled hemorrhoidopexy is associated with less post-operative pain and early resumption of ADL. Although the procedure appears simple to perform, it can be associated with serious complications and still cannot be considered the standard of care for the operative treatment of internal hemorrhoids.