Cost Comparison of Peri-Strips Dry®/Peri-Strips Dry with Veritas® (PSD/PSD-V) Versus Seamguard® in Gastric Staple Line Reinforcement (SLR)

The prevalence of morbid obesity (body mass index (BMI) >=40 kg/m2) is highest among men and women in high-income western countries (men=3.3%; women=5.7%) [1]. Lowand middle-income countries such as those in Latin America have lower prevalence, but the rate of morbid obesity among adults is increasing rapidly [1]. In the last decade (2007-2016), prevalence of morbid obesity among adult men and women in Latin America has approximately doubled (2.1 and 1.5 times) to 1.2% and 3.2%, respectively [1]. Abstract Background: A recent meta-analysis of staple line complications (SLC) in primary bariatric/metabolic procedures showed significantly lower (p<0.05) SLC rates for bovine pericardium (Peri-Strips Dry/Peri-Strips Dry with Veritas (PSD/PSD-V); Baxter Healthcare, Deerfield, IL) compared to biocompatible glycolide copolymer buttress (Seamguard; W.L. Gore & Associates, Inc, Flagstaff, AZ), suture reinforcement (oversewing), and no reinforcement.

Bariatric surgery is indicated to manage morbid obesity, severe obesity (BMI=35-39.9 kg/m2) with obesity-related comorbidities, and obesity (30-34.9 kg/m2) with difficult to control comorbidities [2]. The American Society for Metabolic and Bariatric Surgery (ASMBS) has favorably compared the most common bariatric surgery procedures -Roux-en-Y gastric bypass (gold standard) and sleeve gastrectomy -for management of weight and comorbidities [3]. Sleeve gastrectomy has overtaken Roux-en-Y gastric bypass as the most common primary bariatric/metabolic procedure worldwide [4]. However, the most common surgery type in many Latin American countries continues to be Roux-en-Y gastric bypass by a wide margin [5].

High cost of staple line complications (SLC)
According to the annual report on outcomes after bariatric surgery published by the International Federation for the Surgery of Obesity and Metabolic Disorders (IFSO), most primary bariatric/metabolic procedures are conducted laparoscopically worldwide (99.3%) with a good safety profile [5]. However, staple line complications (SLC), such as hemorrhage (weighted average across procedures=2.76%) and leak (weighted average across procedures=2.46%) may be severe [6]. Multiple studies have

Reduce SLC using Peri-Strips Dry with Veritas (PSD-V) for staple line reinforcement (SLR)
Staple line reinforcement (SLR) is the reinforcing or buttressing of the gastric staple line with the goal of reducing SLC following primary bariatric/metabolic surgery. There is no standard of care (SOC) for gastric SLR [11]. In fact, during many primary bariatric/ metabolic surgeries no SLR is administered, likely due to perceived cost [6]. To fill this gap in care, multiple products and methods have been deployed for SLR. Peri-Strips Dry® with Veritas® Collagen Matrix (PSD-V; Baxter Healthcare, Deerfield, IL) is prepared from dehydrated bovine pericardium procured from cattle under 30 months of age in the United States [12]. PSD-V was preceded by Peri-Strips Dry® Bovine Pericardium Strips (PSD; Baxter Healthcare, Deerfield, IL) [13]. Seamguard (W.L. Gore & Associates, Inc, Flagstaff, AZ) is another commonly used buttressing option made from synthetic biocompatible glycolide copolymer [14].
Another method of gastric SLR is oversewing of the suture line; however, this is associated with increased OR time.
The American Society for Metabolic and Bariatric Surgery (ASMBS) database of bariatric surgeries shows low rates (<1%) of leaks and bleeds for both sleeve gastrectomy and Roux-en-Y gastric bypass in the US [3]. A recent meta-analysis by Shikora et al. (2015) based on 253 studies covering 66,727 unique patients favorably compared PSD/PSD-V to Seamguard, oversewing, and no SLR for primary gastric bypass and sleeve gastrectomy surgeries [6]. Overall, the use of PSD/PSD-V for gastric SLR was associated with a significant reduction in SLC including both leaks and bleeds after both gastric bypass and sleeve gastrectomy [6]. The aim of this study is to apply costs to those results and assess the impact of SLR choice on costs and outcomes of primary gastric bypass and sleeve gastrectomy from the hospital administrator perspective in the US, Brazil, Colombia, and Mexico.

Materials and Methods
A cost-consequence model was developed to compare the cost impact associated with using PSD/PSD-V for SLR in primary bariatric/metabolic surgery as compared to other SLR methods including Seamguard, oversewing, and no reinforcement. Costs from the hospital administrator perspective include the difference in the distribution of surgeries, rates of SLC including leaks and bleeds, surgery time, and product costs. Four countries were selected based on geographic region (Americas) and availability of country-specific data: the US, Brazil, Colombia, and Mexico.
Epidemiologic, clinical, and cost inputs are shown in Table 1 (by SLR method) and Table 2 (by country).

Epidemiologic Inputs
Country-specific rates of gastric bypass and sleeve gastrectomy are from the international survey of primary bariatric/metabolic performed annually by IFSO [15]. The rates of gastric bypass and sleeve gastrectomy data for Brazil were supplemented with a report by the Brazilian Ministry of Health [16]. The rates of gastric bypass and sleeve gastrectomy data for the US were supplemented with data from US databases [17,18]. The proportions of procedures using each type of SLR -PSD/PSD-V, Seamguard, oversewing, and no SLR -are from the meta-analysis by Shikora et al. (2015) [6] for Latin American countries with supplemental information from US databases for the US [17][18][19]. As bariatric surgical centers are often specialized, annual outcomes are reported based on a high-volume hospital performing 100 surgeries per year [20,21].

Clinical Inputs
The Operating room time for gastric bypass and sleeve gastrectomy by SLR method were taken from the literature [25][26][27]. Because the length of surgery for gastric bypass with oversewing SLR could not be identified, the same percentage increase (24%) in the length of surgery for sleeve gastrectomy with oversewing versus with no SLR was applied [26].

Cost Inputs
Product Costs: Given lack of visibility to product costs in each country, costs for PSD-V and Seamguard are based on the US average sales price (ASP) in 2018 [28]. Product and all other costs were exchanged and inflated to 2018 currency using the exchange rates and country-specific consumer price index (CPI) published by the International Monetary Fund (IMF) [29,30].

Cost of Complications:
The associated cost of a SLC (leak or bleed) was applied to the specific surgery type. For bleed complications, the additional cost of a blood bank event (6 units) was added [31].
Costs of complications following sleeve gastrectomy for Brazil,

Sensitivity Analysis
Sensitivity analyses were conducted for both annual net cost impact results and net cost impact results per procedure. Oneway sensitivity analyses used the 95% confidence intervals or +/-20% when the confidence interval was not available. Probabilistic

Am J Biomed Sci & Res
Copy@ Manuel G Ramirez    given that the lower bound of the 95% confidence interval in each country still shows cost savings across 5000 iterations.

Limitations:
In the case of the distribution of SLR methods across procedures, country-specific inputs were not available. Variability in this input was allowed in both the one-way sensitivity analysis and PSA, but the relative influence of annual net cost savings from primary bariatric/metabolic procedures was not large. Only the US distribution of SLR use for gastric bypass was a top-5 influencer of annual net cost savings for primary metabolic procedures.
Based on our modelled results, more gastric bypass and sleeve gastrectomy procedures being performed without SLR or using the Seamguard and oversewing methods would lead to greater benefit of PSD/PSD-V in terms of patient outcomes and a low to positive cost impact in favor of PSD/PSD-V.
Additionally, given lack of data, US product costs for PSD/PSD-V, Seamguard and oversewing were converted to local currencies and used as a proxy for Brazil, Colombia and Mexico. The costs of PSD/ PSD-V and Seamguard were both influential in sensitivity analysis.
In the US, these costs per firing for these products are roughly equivalent. Therefore, a hospital administrator is acquiring both products for different prices, the results of this research may not hold (Appendix 1-3). Colombia, and, Mexico, respectively, by using PSD/PSD-V rather than other SLR choices. Despite the acquisition cost of PSD/PSD-V, SLR using PSD/PSD-V demonstrates cost savings associated with reductions in complications (i.e., leaks and bleeds) and OR time.