Outcomes of a prospective multi-center trial of a second-generation composite mesh for open ventral hernia repair

PURPOSE

Composite mesh prostheses incorporate properties of multiple materials for use in open ventral hernia repair (OVHR). This study examines clinical outcomes in patients who underwent OVHR with a polypropylene/expanded polytetrafluoroethylene (ePTFE) composite graft containing a novel polydioxanone (PDO) absorbable ring to facilitate placement and graft positioning.

METHODS

Data were prospectively collected on consecutive patients undergoing OVHR using a synthetic composite mesh. Seven centers enrolled patients during the study period. All patients underwent a standardized surgical procedure consisting of OVHR with sublay intraperitoneal placement of mesh. Mesh fixation was accomplished with peripheral tacks and transfascial sutures.

RESULTS

One hundred and nineteen patients underwent OVHR with the composite mesh. Average age was 55.8 years; there were 71 (59.7 %) females and 48 (40.3 %) males with mean BMI of 33.5 ± 7.1 kg/m(2). One hundred and two (85.7 %) patients presented with primary ventral hernias. Mean defect size was 13.6 cm(2), and mean mesh size was 113.6 cm(2). Most patients (67 %) were discharged the day of surgery. Twelve patients (10.1 %) experienced complications in the perioperative time period primarily consisting of seroma (4.2 %) and ileus (1.7 %). Two patients required reoperation and mesh removal in the early postoperative period for infection and herniorrhaphy site pain, respectively. There was a decline in pain and movement limitation scores between baseline and 1-year follow-up. Six-month (n = 109) and twelve-month (n = 99) follow-up revealed no hernia recurrences (95 % CI 0-3 %, and 0-4 %, respectively).

CONCLUSIONS

The use of this second-generation composite mesh was associated with no hernia recurrences and a low complication rate after open ventral hernia repair.

Evaluation of a new self-developing instant film for imaging and dosimetry

Radiation sensitive films are standard dosimetric tools in radiation therapy. Films are used for machine quality assurance (QA) and treatment planning software evaluation. With the advent of intensity modulated radiation therapy (IMRT), simple and fast imaging technology is needed for patient-specific verification of radiation fields. Conventional radiographic films are often used. Radiochromic films, e.g. Gafchromic films, were recently introduced to the market. But these films have some disadvantages. JP Laboratories have developed a prototype radiochromic film, called SIFID (self-developing, instant film for imaging and dosimetry) with superior performance such that SIFID is unaffected by ambient light for months, stable up to 90 degrees C and can be archived. SIFID is made of polymerisable diacetylene. The film develops blue colour instantly upon absorbing radiation. We evaluated the film for radiation therapy applications. Our preliminary data demonstrate its feasibility as a dosimetric tool for IMRT QA as well as for other applications.

Modeling alternation to synchrony with inhibitory coupling: a neuromorphic VLSI approach

We developed an analog very large-scale integrated system of two mutually inhibitory silicon neurons that display several different stable oscillations. For example, oscillations can be synchronous with weak inhibitory coupling and alternating with relatively strong inhibitory coupling. All oscillations observed experimentally were predicted by bifurcation analysis of a corresponding mathematical model. The synchronous oscillations do not require special synaptic properties and are apparently robust enough to survive the variability and constraints inherent in this physical system. In biological experiments with oscillatory neuronal networks, blockade of inhibitory synaptic coupling can sometimes lead to synchronous oscillations. An example of this phenomenon is the transition from alternating to synchronous bursting in the swimming central pattern generator of lamprey when synaptic inhibition is blocked by strychnine. Our results suggest a simple explanation for the observed oscillatory transitions in the lamprey central pattern generator network: that inhibitory connectivity alone is sufficient to produce the observed transition.