Effectiveness of bedside staplers in bariatric robotic procedures

Background Few studies have evaluated the use of laparoscopic staplers in robotic procedures (bedside stapling, BS). This study aims to evaluate the effectiveness of BS compared with robotic staplers (RS) in bariatric robotic procedures. Methods Patients who underwent robotic sleeve gastrectomy or gastric bypass elective procedures between 1/1/2021 and 12/31/2021 were extracted from PINC AI™ Healthcare Data. The following clinical outcomes were compared: blood transfusion, bleeding, anastomotic leak, intensive care unit (ICU) visit, and 30-day readmission, operating room (OR) time, inpatient costs, and length of stay. We evaluated baseline balance in BS and RS and bivariate association between covariates and outcomes using Chi-square or Fisher exact test and t-test or ANOVA. Multivariable general linear mixed models (GLMMs) with respective gamma or binomial distribution and log-link function were used to obtain adjusted outcomes variations between BS and RS. Results Total of 7268 discharges were included with 1603 (22.1%) BS and 5665 (77.9%) RS cases. RS cases consisted of a higher number of patients who were Hispanic (17.0% vs. 9.4%), had Medicaid (26.9% vs. 19.4%) and underwent sleeve gastrectomy (68.4% vs. 53.5%). Higher proportions of RS cases were done by providers in Northeast region (35.5% vs. 24.3%), smaller size (< 500 beds; 71.1% vs. 52.3%), and teaching hospitals (59.4% vs. 39%). The adjusted outcomes variations demonstrated that patients that had RS were significantly more likely to have blood transfusions, ICU stays, increased ORT (19 min) and costs ($1273). Sensitivity analysis showed similar results, except no significant differences in blood transfusion rates in both groups. Conclusions Bedside staplers significantly reduce healthcare resource utilization with equivalent effectiveness and fewer ICU stays compared to robotic staplers. Graphical abstract Supplementary Information The online version contains supplementary material available at 10.1007/s00464-024-11045-w.

Surgical stapling is ubiquitous in abdominal surgery.Surgical staplers have advanced through the years and have now become automated.They now include built in safety features as well as the capability to sense tissue thickness and resistance to the device.This feedback in real time can allow the surgeon to modify staple cartridge size to accommodate thicker or thinner tissue.The safety profile of these staplers is very high, with an estimated failure rate of 1 in 8000 firings [1].Even then, most of those events are not clinically significant, and are usually just an equipment failure with no risk to the patient.We previously reported on the safety of stapling devices and found that the most common adverse event reported to the Food and Drug Administration was failure to fire for both Medtronic and Ethicon.Failure to fire can be time consuming and frustrating to the surgeon but has little chance of harming the patient.The efficacy of these staplers is proven daily, and data from the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP) demonstrates very low leak and bleeding rates [2].The MBSAQIP does not have the granularity to determine if stapling devices are directly responsible for leaks or bleeding, but with the rise of the sleeve gastrectomy (SG), which is a purely stapling procedure, most surgeons recognize the role of the stapler in these two complications.
In the last decade, a third company has entered the arena of surgical stapling.Intuitive Surgical introduced the robotic platforms stapler in 2012 [3].The first iteration of this robotic stapler (RS) was the Endowrist™ and later it has been refined to the Sureform™.There is little data reported on this stapler, but by evaluating the MBSAQIP, suppositions about its safety can be made.According to the latest American Society of Metabolic and Bariatric Surgeons estimates, robotic-assisted cases made up 30% of total bariatric operations in 2022 [4].There is no statistically significant increase in leakage in these cases compared to non-robotic, again demonstrating equivalent safety.However, these observations are muddled by the fact that not all robotic surgeons use the robotic stapler.The type of stapler used is not reported in the MBSAQIP, so a robotic case may or may not have used a robotic stapler.There are a few reasons for this, including surgeon comfort level with their traditional bedside staplers and distrust in the first-generation robotic stapler.
Few studies have evaluated results of non-robotic bedside staplers (BS) used in robotic procedures [5][6][7].In addition, a previous study showed that robotic staplers need more reloads to complete the gastric pouch and the overall stapling costs were higher than bedside staplers [8].The objective of this study is to evaluate the effectiveness of bedside staplers compared with robotic staplers during bariatric robotic-assisted procedures using a nationwide hospital-based database.

Data sources
Data were extracted from the PINC AI™ Healthcare Data (PHD).The PHD comprises U.S. hospital-based, servicelevel, all-payor information on inpatient discharge [9].More than 1400 hospitals/healthcare systems contribute data to the PHD with more than 9 million visits per year since 2012, representing approximately 25% of annual United States inpatient admissions.The PHD contains information on hospital and visit characteristics, admitting and attending physician specialties, healthcare payers, and patient data, including demographics, disease states, diagnoses, costs, medications, and device details from standard hospital discharge billing files.The PHD is de-identified in accordance with the HIPAA Privacy Rule.This study was determined exempt from full board review by Sterling IRB.

Study population
Patients who underwent primary sleeve gastrectomy (SG) or Roux-en-Y gastric bypass (RYGB) with a robotic system in the inpatient setting between 1/1/2021 and 12/31/2021 were obtained from PINC AI™ Healthcare Data.Inclusion criteria were patients whose procedure used BS and RS, had all the key variables, and had non-zero costs (Fig. 1).Robotic procedures were defined as an inpatient claim with a secondary procedure code (International Classification of Diseases version-10 [ICD 10 PCS]) or any claim with a Current Procedure Terminology (CPT) code indicated as a robotic procedure or patients charged with robotic supplies.These included CPT code S2900, ICD-10 code 8E0W4CZ.

Study design
This study is based on Donabedian A 4 ."Structure-Process-Outcomes Quality Framework" to evaluate outcomes (clinical outcomes and healthcare resource utilization) effectiveness of bariatric robotic procedures (Fig. 2) [10].

Clinical outcomes and healthcare resource utilization
Clinical outcomes included the rates of blood transfusion, bleeding, anastomotic leak, intensive care unit (ICU) visits, and 30-day urgent and emergency room readmission.We used ICD-10 diagnosis and procedures codes and CPT codes to identify blood transfusion, bleeding, and anastomotic leak from patients' inpatient claim file.Premier 'READMIT' file and charge master files were used to identify ICU and readmission.Healthcare resource utilization included operating room (OR) time in minutes obtained from the hospital charge file, costs (in US dollars), and length of stay (in days).
The key variable evaluated in the study is the type of stapler.We grouped staplers into two groups: bedside staplers included Johnson and Johnson Ethicon™ or Echelon™ staplers and Medtronic Signia™, Endo Gia™, Tri-staple™ staplers; the robotic staplers included the latest Intuitive SUREFORM™ staplers.The manual/intelligent bedside staplers (MIBS) subgroup only included Medtronic beside staplers.All types of staplers were used product name/product number as text searching through the hospital change master file.
All study codes are listed in Supplementary Table 1.

Statistical analysis
Effectiveness was measured by clinical outcomes and healthcare resource utilization.The covariates to evaluate effectiveness included baseline patient and provider characteristics.We evaluated baseline balance in BS and RS and the bivariate association between covariates and outcomes using

Sensitivity analysis
For testing the robustness of the results, two additional modeling approaches for sensitivity analyses are used.First, we used propensity score matching methods to adjust baseline imbalance for two types of staplers.We performed a 1:1 match between bedside staplers and robotic staplers with a maximum caliper width of 0.2 for the absolute probability using the nearest neighbor technique without replacement.
All baseline patients and provider characteristics were input into a logistic regression model for propensity score matching.The chi-squared, fisher exact, or paired t-test was used to examine the outcomes of the post-matched cases [11].Secondly, we used propensity scores covariate adjustment multivariable general linear mixed models to estimate the outcome variations between types of staplers used.The propensity score calculation was based on all baseline patients and provider characteristics.The statistical significance was determined if p-value < 0.05.All data management and analyses were conducted using SAS 9.4 software (SAS Institute Inc, Cary, NC) using 2-sided statistical tests.

Sensitivity analysis
Our sensitivity analysis-propensity score covariate adjustment GLMMs showed similar results except no significant differences in blood transfusion rates between BS and RS (Tables 3 and 4).The propensity scores matching (PSM) method did not obtain enough matched pairs for an unbiased estimation of outcomes variations, for BS versus RS (1517 pairs, 94.6% of cases were matched) and for MIBS versus RS (657 pairs, 76.1% of cases were matched).
However, the results of PSM were similar to the other two approaches (Table 5).

Discussion
The important findings of this study were that bedside staplers had better outcomes than robotic staplers in terms of lower rates of blood transfusion, less ICU stays, shorter operative time and lower costs.The difference in blood transfusion was not shown in the GLMM sensitivity analysis.It should be noted that these findings are from a single year (2021) using data from a hospital-based database.But they may be generalizable to the bariatric population as a whole, since this data is collected on a national level.This study helps to clarify outcomes related to the type of stapler in robotic-assisted cases.Up until now, it was difficult to determine if complications in robotic surgery were secondary to the type of stapler used.This is because most papers use the MBSAQIP database for short-term outcomes.But there is no way to determine what type of stapler was used in the MBSAQIP database, as that is not reported data.That is why the PINC AI™ was used to evaluate this, as each stapling company's product could be individually evaluated.However, it is important to note that this data is from 2021, and in the last 3 years surgeon use of RS may have dramatically increased [4].In fact, the ASMBS Task Force in bariatric volume reported a rate of 30% robotic-assisted cases in 2022.
Bedside stapling was the norm for robotic-assisted bariatric operation until Intuitive released their first generation of endoscopic staplers.But even then, many surgeons continued to use beside staplers.Intuitive has continuously improved their stapler and released a newer version.The robotic platform also can be modified with software updates to improve performance of the RS.The rate of bedside stapling will likely decrease over time in robotic-assisted cases as time goes by.
The question remains; however, will surgeons continue to use BS with the Intuitive robotic platform?Bedside staplers have a long track record and have improved continuously over the years.There is force feedback in these staplers and tissue sensing technology.Many surgeons have their assistant fire the stapler at the bedside and prefer to have a skilled assistant there.There is also a familiarity factor and mid to late career surgeons have used these staplers literally tens of thousands of times and may be resistant to changing from a product they are very comfortable with.

Study limitation
Due to small or zero events for ICU visits in the comparison of Medtronic staplers versus SUREFORM, we used a modified model (Firth or Fisher exact) to analyze and estimate the rate of ICU visits.As a result, the 95% confidence interval was wide.Another limitation is that the hospitalbased database does not include the granularity of staple load (height) and staple line reinforcement.These factors can affect the formation of staples and outcomes and we were unable to account for these two factors.

Conclusion
Bedside staplers significantly reduce healthcare resource utilization with equivalent effectiveness and fewer ICU stays compared to robotic staplers.
Funding No funding support for this study, I-Wen Pan is a full-time employee of Medtronic plc.

Table 1
Patient and provider characteristicsChi-square or Fisher exact test and t-test or ANOVA.Multivariable general linear mixed models (GLMMs) with respective gamma or binomial distribution and log-link function were used to obtain the variations of adjusted outcomes and healthcare resources utilization between BS and RS.Additionally, a subgroup analysis was performed to analyze the effectiveness of manual/intelligent bedside staplers.
The bold shows statistical significance, p-value < 0.05 RS robotic staplers, BS bedside staplers, MIBS manual/intelligent bedside stapler

Table 2
Unadjusted clinical outcomes and health care resources utilization by types of staplers

Table 3
Adjusted clinical outcomes variations between robotic staplers and the compared bedside staplersThe bold shows statistical signficance, p-value < 0.05GLMMs general linear mixed model, CI confidence interval, RS robotic staplers, BS bedside staplers, MIBS manual/intelligent bedside staplers, ICU intensive care unit a Multivariable GLMMs: Multivariable general linear model with log link and binomial family function b Propensity score covariate adjustment GLMMs: propensity scores adjusted general linear model with log link and binomial family function president California chapter ASMBS (unpaid) and current executive Council Member ASMBS (unpaid).Billy also holds GT Metabolic stock (No payment made).Dr. Rami Lufti received educational grant from Gore Medical (The grant is to the Institution).He also received

Table 4
GLMMs general linear mixed model, CI confidence interval, RS robotic staplers, BS bedside staplers, MIBS manual/intelligent bedside staplers, OR odds ratio, LOS length of stay, USD United States dollars a Multivariable GLMMs: multivariable general linear mixed model with log link and Gamma family function b Propensity score covariate adjustment GLMMs: using propensity scores to replace covariates in the GLMMs

Table 5
The results of the propensity score matched cohort OR odds ratio, LOS length of stay USD United States dollars, ICU intensive care unit a Covariates for propensity score matching included procedure and all patient and provider characteristics, 657 manual/intelligent bedside stapling and robotic stapling cases were paired b 1517 (94.6%) of 1603 bedside and robotic stapling cases were matched c 657 (76.1%) of 863 manual/intelligent bedside stapling and robotic stapling cases were paired consulting fees from Medtronic, Ethicon, and Gore Medical.I-Wen Pan is a full-time employee of Medtronic Plc.Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made.The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material.If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.