An Opening in the Abdomen An Opening in the Market: Hernia Tensiometer

An Opening in the Abdomen An Opening in the Market: Hernia Tensiometer GROUP 2: Martha Ingram Megan Johnston Chelsea Samson

What Is a Hernia?

Laparoscopic Open

“Tension-Free” Repair Method

Making the Case for Hernia research BK Poulose, MD, MPH; J Shelton, MD; S Phillips, MSPH; DE Moore, MD, MPH; W Nealon, MD; D Penson, MD, MPH; MD Holzman, MD, MPH Background: • “Currently, there is a lack of standardization in ventral hernia repair procedures, with widespread variation in delivery” • Lack of standard delivery Increased complications post-surgery increased cost Methods: $ Inpatient discharges from 2001-2006 Healthcare Cost and Utilization Project $ Outpatient estimates from 2006CDC National Survey of Ambulatory Surgery $ Total number of ventral hernia repair procedures performed in the U.S. $ Extrapolated operation dollars from 2006 to 2009 monies using Consumer Price Index

Results In 2006: • 154,278 inpatient + 193,543 outpatient = 348,000 operations • 1 inpatient operation = $15,374 • 1 outpatient operation = $3,745 • Total Expenditure in Procedures =$3.1 billion on VHR

Mean Cost of Ventral Hernia Repair Procedures over Time Cost per Discharge Year *adapted from BK Poulose, J Shelton, DE Moore, W Nealon, D Penson, M Holzman, Making the Case for Hernia Research. 2011.

Mean Frequency of Ventral Hernia Repair Operations over Time Number of Discharges Year *adapted from BK Poulose, J Shelton, DE Moore, W Nealon, D Penson, M Holzman, Making the Case for Hernia Research. 2011.

It is estimated that a 1%reduction in VHR operations could save $31 millionin Healthcare costs in the U.S. per year The application of an intra-operative tension-measuring device could increase understanding of and prevent hernia recurrence, significantly decreasing costs

Device Must: • Measure tension resisting closure at the suture line after: • - dissection of the injury area • - separating fascia from muscle • placing the mesh • Isolate abdominal tissue • Bring edges together • Read tension at center of hernia

User Feedback: Get a force (Newtons) and want to know if failure will occur… Probability of Recurrence 100 % 90 % 80 % 70 % 60 % 50 % 40 % 30 % 20 % 10 % 0 % Tension (N)

User Response: • Relaxing Incisions • Suture Closed • Mesh Placement

Lash force sensors across opening Clamp both hernia edges between metal plates Large, sharp serrations hold tissue in place

Digital display Gear to wind hernia edges together Mobile arm Force Sensor Static arm

Indentation Testing

Calibration 1. Initial calibration • Known weights (0-5 kg) applied • Measure voltage output in Labview • Convert to force 2. Tare • Zero weight  zero force 3. Pre-operative testing • Surgeons will calibrate with weights every 5-10 uses to confirm precise results (calibration curve is still relevant)

Timeline – Near Future • Attach sensors and test with weights – today • Test on porcine model – 4th week of Feb • Modify design – early March

An Opening in the Abdomen An Opening in the Market: Hernia Tensiometer