BREAST The Use of Mesh versus Primary Fascial Closure of the Abdominal Donor Site When Using a Transverse Rectus Abdominis Myocutaneous Flap for Breast Reconstruction: A Cost-Utility Analysis Abhishek Chatterjee, M.D., M.B.A. Dipak B. Ramkumar, M.D. Tamara B. Dawli, M.D. John F. Nigriny, M.D. Mitchell A. Stotland, M.D. Emily B. Ridgway, M.D. Lebanon, N.H.
T
Background: During breast reconstruction using the transverse rectus abdominis myocutaneous (TRAM) flap, the use of mesh for abdominal donor-site closure provides for a technology that potentially offers clinical benefit yet incurs an added cost. The authors’ goal was to determine whether it is cost effective to use mesh during abdominal donor-site closure when performing a TRAM flap for breast reconstruction. Methods: A literature review was conducted to identify and collect published hernia and bulge rates at abdominal TRAM flap donor sites closed either primarily or with mesh. A decision tree analysis was performed. Outcome probabilities, costs of complications, and expert utility estimates were populated into the decision tree model to evaluate the cost-utility of using mesh in TRAM abdominal donor-site closure. One-way sensitivity analyses were performed to verify the robustness of the results. Results: The authors’ literature review resulted in 10 articles describing 1195 patients who had TRAM abdominal donor-site closure primarily and 696 patients who had donor-site closure performed with mesh. Pooled hernia/bulge complication rates for these two groups were 7.87 percent and 4.45 percent, respectively. The use of mesh was more clinically effective based on total quality-adjusted life-years gained of 30.53 compared with 30.41 when performing primary fascial closure alone. The incremental additional cost incurred by the mesh arm when running the decision tree model was $693.14. This difference in cost, divided by the difference in clinical efficacy (0.12), results in an incremental cost-utility ratio value of $5776.17 per quality-adjusted life-year gained when using mesh, making it cost effective (when using a willingness-to-pay threshold of $50,000). One-way sensitivity analysis revealed the following: (1) using mesh was a cost effective option, provided that the price of mesh was less than or equal to $5970; (2) mesh was cost effective when its use led to a hernia/bulge rate less than or equal to 7.25 percent; and (3) primary facial closure was cost effective when its use led to a hernia/bulge rate less than or equal to 4.75 percent. Conclusion: The use of mesh when repairing the abdominal donor site during a pedicled or free TRAM flap breast reconstruction is cost effective compared with primary fascial closure alone. (Plast. Reconstr. Surg. 135: 682, 2015.)
here has been substantial literature evaluating the clinical benefit of using mesh reinforcement versus primary fascial repair
From the Dartmouth-Hitchcock Medical Center. Received for publication May 30, 2014; accepted August 8, 2014. Presented at the 55th Annual Meeting of the New England Society of Plastic and Reconstructive Surgeons, in Sebasco Estates, Maine, June 6 through 8, 2014; and at Plastic S urgery The Meeting, in Chicago, Illinois, October 10 through 14, 2014. Copyright © 2015 by the American Society of Plastic Surgeons DOI: 10.1097/PRS.0000000000000957
682
of the abdominal donor site when performing a transverse rectus abdominis myocutaneous (TRAM) flap breast reconstruction.1–8 Although a perceived clinical benefit may exist in the use of mesh, the addition of this technology also adds a significant cost to the operation. This conflict of a Disclosure: Dr. Chatterjee is a speaker for LifeCell Corp. He has received no direct funding for this research project in particular. The other authors have no conflicts of interest to declare.
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Volume 135, Number 3 • Mesh versus Primary Fascial Closure technology offering a potential clinical advantage over the status quo while also potentially costing creates the need to perform a cost-utility analysis. This type of analysis weighs the clinical benefit and the added cost to assess whether a technology is cost effective compared with the status quo. To date, there has been no cost-utility study evaluating the use of mesh to reinforce the abdominal donor site when using a TRAM flap for breast reconstruction. Given this, our goal was to perform a cost-utility analysis to see whether there was a cost-utility benefit in using mesh (both synthetic and biological) versus primary fascial closure at the abdominal donor site in breast reconstruction patients undergoing TRAM flap surgery.
PATIENTS AND METHODS The use of mesh in the abdominal donor-site closure after TRAM flap harvesting for breast reconstruction has been well documented.1–8 As with the addition of any implantable material during an operation, the mesh may add not only clinical benefit but also increased cost. This perception of clinical benefit along with increased associated costs invites analysis that considers the relationship between cost and utilities. Cost-utility analysis is composed of costs, probabilities, and utilities of various health outcomes (health states) that are used to evaluate competing interventions.9–17 Perspective The perspective of the hospital was adopted for the decision analysis. Secondary data were used in this analysis for which it was impossible to estimate the productivity costs to the patient and the patient’s family; thus, adopting a societal perspective would be inappropriate.16,18 Health States The relevant surgical literature was explored to properly identify the most common and clinically pertinent abdominal donor-site mesh complications associated with free and pedicled TRAM flap breast reconstruction. These meshrelated complications primarily included abdominal bulge and hernia.1–8,19–22 Infections related to mesh were not included in the decision analysis, given that these complications were rare ( 0 and < willingness to pay, willingness to pay = $50,000. One-way sensitivity analysis was performed to determine whether the baseline decision analysis was robust by varying the hernia/bulge complication rate when using primary fascial closure and when using mesh and observing how this affected the incremental cost-utility ratio. One-way sensitivity analysis was also performed to calculate the maximum price of mesh that would allow it to be cost effective. All of the above statistical calculations were performed using TreeAge Pro 2012 (TreeAge Software, Inc., Williamstown, Mass.). This study was conducted in accordance with the principles outlined in the Declaration of Helsinki.
RESULTS The literature review1–8,19–22,25,26 revealed that the complication rate was heavily dominated by abdominal hernia/bulges with and without the use of mesh when repairing the abdominal donor site after TRAM flap harvest (Table 1). When performing primary closure of the abdominal donor site, the abdominal hernia/bulge rate was 7.87 percent versus 4.45 percent when using mesh as a reinforcement. The cost-utility analysis revealed a baseline cost difference of $693.14, a gain in quality-adjusted life-years of 0.12, and an incremental cost-utility ratio of $5776.17 per quality-adjusted life-year gained with the use of mesh closure compared with primary fascial closure (Table 2). This is substantially less than the $50,000 threshold (marking the upper limit of willingness to pay), making the use of mesh a cost-effective option. One-way sensitivity analysis (Table 2) performed by varying mesh pricing while holding other variables constant revealed that using mesh
685
Plastic and Reconstructive Surgery • March 2015 Table 2. Cost Utility and Sensitivity Analysis
Baseline analysis Sensitivity analysis (when using mesh) Recurrence rate (with mesh) = 7.25% Sensitivity analysis of maximum mesh cost Cost of mesh = $5970
Cost Difference ($)
QALY Gained
Cost ($) per QALY Gained (ICUR)
693.14
0.12
5776.17
739.54
0.02
36,977.00
5913.14
0.12
49,276.17
QALY, quality-adjusted life-year; ICUR, incremental cost-utility ratio.
to repair the abdominal donor site was a cost-effective option, provided that the price of mesh was less than or equal to $5970. Similarly, one-way sensitivity analysis (Table 2), performed by varying abdominal hernia/bulge rates when using mesh, revealed that the use of mesh during TRAM flap abdominal donor-site closure is cost effective when its use leads to a hernia/bulge rate less than or equal to 7.25 percent. A hernia/bulge rate of greater than 7.25 percent, when using mesh, led to a qualityadjusted life-year gained of greater than $50,000, thus making it cost-ineffective. Lastly, one-way sensitivity analysis revealed that when all other variables are held constant, primary facial closure of the abdominal donor site is cost effective when its use leads to a hernia/bulge rate less than or equal to 4.75 percent.
DISCUSSION The difficulty of assessing an intervention that improves clinical outcomes yet adds cost to the health care system is an area of study in which cost-utility analysis proves most useful.18 Within the arena of cost analysis, cost-utility analysis studies the clinical outcomes of a surgical intervention and translates it into quality-adjusted life-years. These quality-adjusted life-years are then compared to the costs of the surgical intervention to create a cost per quality-adjusted life-year, also known as the incremental cost-utility ratio.16,18 This ratio provides the marginal cost incurred by a new intervention per quality-adjusted life-year gained. The decision to choose this newer or alternative intervention is based on a predetermined, acceptable upper cost limit per quality-adjusted life-year. Ranges in the literature between $20,000 and $150,000 per quality-adjusted life-year have been proposed, depending on which health care system or payer group is involved.29,30 Our threshold for cost-effectiveness at $50,000 per quality-adjusted life-year was chosen based on historical precedent.28 This number was felt to be a conservative estimate for the maximum willingness of a society to pay based on both domestic and international standards.30
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Based on our results, the use of synthetic mesh is a cost-effective option when closing the abdominal donor site of the TRAM flap being used for breast reconstruction. The incremental cost-utility ratio value of $5776.17 per qualityadjusted life-year gained demonstrates that the cost effectiveness of using mesh is derived from the decreased hernia rate of 4.45 percent with its use. This increased clinical benefit makes the additional cost of the mesh acceptable. These findings support the use of mesh at the abdominal donor site and provide a cost-outcomes conclusion. Our literature review demonstrated that by far the most prevalent TRAM flap donor-site complication is abdominal hernias/bulges (Table 1). Although other donor-site complications are associated with TRAM flap breast reconstruction, the purpose of this study was to look at a decision analysis focusing on whether or not to use mesh in repairing the abdominal donor site. For this reason, complications such as hematomas, seromas, and abdominal wall weakness were not included in the decision analysis. Our literature review did not show that these complications were specifically associated with the use of mesh; thus, they were not included in this particular decision analysis. Sensitivity Analysis Our one-way sensitivity analysis (Table 2) revealed that by varying the probability of an abdominal hernia/bulge complication occurring with the use of mesh, a probability of 0.0725 (7.25 percent) or lower was associated with increased cost-effectiveness of using mesh. Certain assumptions were made, including the maximum willingness-to-pay amount for a quality-adjusted life-year was $50,000, the distribution of specific complications remained constant, and the complication rate of primary fascial closure remained constant at 7.87 percent. If one were to prefer to use a primary fascial closure technique for the abdominal donor site, our sensitivity analysis revealed that by varying the probability of an abdominal hernia/bulge complication occurring with primary fascial closure alone, a probability of 0.0475 (4.75 percent) or lower was
Volume 135, Number 3 • Mesh versus Primary Fascial Closure associated with increased cost-effectiveness without using mesh. Again, similar assumptions were made, namely, that the complication rate of closure with mesh remained constant at 4.45 percent. Lastly, a one-way sensitivity analysis was performed by varying the price of mesh and holding other variables constant, and demonstrated that the maximum cost-effective price of mesh was $5970 or less. Mesh Choice and Surgeon Autonomy The use of cost-effectiveness analysis in decision making should be studied collaboratively by decision makers and analysts to improve its usefulness. In cost-conscious times, especially during an economic recession where health care cost cutting threatens to undermine the autonomy of surgeon choice, cost-utility analysis provides the surgeon an empowering tool that validates clinical judgment. An example of this is demonstrated by the one-way sensitivity analysis that finds the maximum price of mesh to be $5970 at or under which choosing mesh would be a cost-effective option. With this knowledge, the surgeon can justify the clinical benefit and cost of mesh choice, synthetic or biological, when repairing an abdominal TRAM flap donor site. Although the literature demonstrates clinical benefits of using either synthetic or biological mesh, there is no head-to-head comparison of the two when closing an abdominal donor site. However, this cost-utility with its sensitivity analysis justifies the use of either, provided that the cost of the mesh being used is $5970 or less. Limitations One limitation inherent in cost-utility analysis is its reliance on the reliability of the literature in the literature review.31–34 Factors such as chemotherapy were not addressed in the articles reviewed and can present as confounders to outcomes with regard to donor-site healing. In addition, there is an assumption that the data gathered with regard to surgical technique and outcomes when performing TRAM flap operations and the closure of abdominal donor sites is uniform with little variability. Clearly, inherent flaws are present when pooling data from a literature review, given the variability of data collection, patients being operated on, and surgeons performing the operations. One example of this is highlighted by the variability of follow-up periods in the literature. Hernias and bulges can present several years after an operation. By pooling data that represent a sample of patients with follow-ups ranging from 6 months to 6 years, hernias and bulges in this
sample could have been missed if they presented at later times. Until further large-scale, prospective, randomized, unbiased studies are performed, the decision analysis performed here provides a reasonable cost-effectiveness analysis that can aid in decision making when it comes to using or not using mesh to close TRAM flap donor sites. A second limitation involves the assumption that no subsequent recurrences of hernia/bulges occurred after the first revision. By relying on the literature specific to TRAM flap donor-site reconstruction, we modeled our outcomes to what was reported in the literature, which did not assume subsequent recurrences. This may have been attributable to the follow-up period, which may have missed subsequent hernias and bulges. A third limitation involves the grouping of mesh in the literature review that includes both biological and synthetic mesh. On further reviewing the individual articles used, there was no observable difference in hernia/bulge complication rates between biological and synthetic mesh.1,19 This may be because the abdominal donor sites still have some sort of fascia (either rectus sheath or transversalis fascia) remaining over which the mesh supplements and adds strength to the closure. The preference of using one type of mesh over another for abdominal donor-site closure, which constitutes an area for potential future research, is beyond the scope of this article, which compares mesh use to primary fascial closure. A fourth limitation involves the choice of TRAM flaps for breast reconstruction versus other forms of autologous tissue for breast reconstruction. The choice of considering the TRAM flap (free and pedicled) was made because of its common use in breast reconstruction and the abundance of literature available looking at outcomes from this operation. Although other flaps such as the muscle-sparing TRAM flap and the deep inferior epigastric perforator flap are reasonable options for breast reconstruction, the results of this study do not directly address the use of mesh in these types of reconstructions. A fifth limitation involves the inherent lack of opportunity cost in a decision tree analysis. Opportunity cost is the potential gain or loss when a person chooses to perform an activity over its next best alternative.35–37 With respect to surgery, opportunity cost can occur if a less efficient surgical technique uses more overall operating time (by possible complications incurred requiring further operations) than its next best alternative. This additional operating time could be used in a productive way that, when economically valued,
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Plastic and Reconstructive Surgery • March 2015 adds a “cost” to the less efficient surgical technique. In our decision analysis, not using mesh may lead to additional bulges and hernias that adds an expense in time that could otherwise be used productively in performing other operations.
CONCLUSIONS The use of mesh, biological or synthetic, when repairing the abdominal donor site during a pedicled or free TRAM flap breast reconstruction can be cost-effective when compared with primary fascial closure alone. The use of mesh remains a costeffective option, provided that the hernia/bulge recurrence rate with its use remains less than or equal to 7.25 percent or its costs are less than or equal to $5970. If one chooses to use primary closure alone to repair an abdominal donor site, the hernia/bulge rate should be less than or equal to 4.75 percent for this approach to be cost-effective. Abhishek Chaterjee, M.D., M.B.A. Dartmouth-Hitchcock Medical Center One Medical Center Drive Lebanon, N.H. 03756 [email protected]
REFERENCES 1. Chang EI, Soto-Miranda MA, Zhang H, et al. Comprehensive analysis of donor-site morbidity in abdominally based free flap breast reconstruction. Plast Reconstr Surg. 2013;132:1383–1391. 2. Drever JM, Hodson-Walker N. Closure of the donor defect for breast reconstruction with rectus abdominis myocutaneous flaps. Plast Reconstr Surg. 1985;76:558–565. 3. Kroll SS, Marchi M. Comparison of strategies for preventing abdominal-wall weakness after TRAM flap breast reconstruction. Plast Reconstr Surg. 1992;89:1045–1051; discussion 1052. 4. Kroll SS, Schusterman MA, Reece GP, et al. Abdominal wall strength, bulging, and hernia after TRAM flap breast reconstruction. Plast Reconstr Surg. 1995;96:616–619. 5. Mizgala CL, Hartrampf CR Jr, Bennett GK. Assessment of the abdominal wall after pedicled TRAM flap surgery: 5- to 7-year follow-up of 150 consecutive patients. Plast Reconstr Surg. 1994;93:988–1002; discussion 1003. 6. Pennington DG, Lam T. Gore-Tex patch repair of the anterior rectus sheath in free rectus abdominis muscle and myocutaneous flaps. Plast Reconstr Surg. 1996;97:1436–1440; discussion 1441. 7. Clugston PA, Gingrass MK, Azurin D, Fisher J, Maxwell GP. Ipsilateral pedicled TRAM flaps: The safer alternative? Plast Reconstr Surg. 2000;105:77–82. 8. Hartrampf CR Jr, Bennett GK. Autogenous tissue reconstruction in the mastectomy patient: A critical review of 300 patients. Ann Surg. 1987;205:508–519. 9. Cavaliere CM, Chung KC. A cost-utility analysis of nonsurgical management, total wrist arthroplasty, and total wrist arthrodesis in rheumatoid arthritis. J Hand Surg Am. 2010;35:379–391.e2. 10. Chung KC, Saddawi-Konefka D, Haase SC, et al. A cost-utility analysis of amputation versus salvage for Gustilo type IIIB and IIIC open tibial fractures. Plast Reconstr Surg. 2009;24:1965–1973.
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11. Chatterjee A, Krishnan NM, Rosen JM. Complex ventral hernia repair using components separation with or without biologic mesh: A cost-utility analysis. Ann Plast Surg. 2014; doi: 10.1097/SAP.0b013e31829fd306 [Epub ahead of print]. 12. Chatterjee A, Krishnan NM, Rosen JM. Complex ventral hernia repair using components separation with or without synthetic mesh: A cost-utility analysis. Plast Reconstr Surg. 2014;133:137–146. 13. Chatterjee A, Krishnan NM, Van Vliet MM, Powell SG, Rosen JM, Ridgway EB. A comparison of free autologous breast reconstruction with and without the use of laser-assisted indocyanine green angiography: A cost-effectiveness analysis. Plast Reconstr Surg. 2013;131:693e–701e. 14. Krishnan NM, Chatterjee A, Rosenkranz KM, Powell SG, Nigriny JF, Vidal DC. The cost effectiveness of acellular dermal matrix in expander-implant immediate breast reconstruction. J Plast Reconstr Aesthet Surg. 2014;67:468–476. 15. Krishnan NM, Chatterjee A, Van Vliet MM, Powell SG, Rosen JM, Nigriny JF. A comparison of acellular dermal matrix to autologous dermal flaps in single-stage, implant-based immediate breast reconstruction: A cost-effectiveness analysis. Plast Reconstr Surg. 2013;131:953–961. 16. Thoma A, Khuthaila D, Rockwell G, Veltri K. Cost-utility analysis comparing free and pedicled TRAM flap for breast reconstruction. Microsurgery 2003;23:287–295. 17. Ziolkowski NI, Voineskos SH, Ignacy TA, Thoma A. Systematic review of economic evaluations in plastic surgery. Plast Reconstr Surg. 2013;132:191–203. 18. Thoma A, Veltri K, Khuthaila D, Rockwell G, Duku E. Comparison of the deep inferior epigastric perforator flap and free transverse rectus abdominis myocutaneous flap in postmastectomy reconstruction: A cost-effectiveness analysis. Plast Reconstr Surg. 2004;113:1650–1661. 19. Glasberg SB, D’Amico RA. Use of regenerative human acellular tissue (AlloDerm) to reconstruct the abdominal wall following pedicle TRAM flap breast reconstruction surgery. Plast Reconstr Surg. 2006;118:8–15. 20. Moscona RA, Ramon Y, Toledano H, Barzilay G. Use of synthetic mesh for the entire abdominal wall after TRAM flap transfer. Plast Reconstr Surg. 1998;101:706–710; discussion 711. 21. Zienowicz RJ, May JW Jr. Hernia prevention and aesthetic contouring of the abdomen following TRAM flap breast reconstruction by the use of polypropylene mesh. Plast Reconstr Surg. 1995;96:1346–1350. 22. Lejour M, Dome M. Abdominal wall function after rectus abdominis transfer. Plast Reconstr Surg. 1991;87:1054–1068. 23. Ingenix. DRG Expert. Reston, Va: Ingenix; 2012. 24. U.S. Department of Health and Human Services. Physician Fee ScheduleSearch.Availableat:http://www.cms.gov/apps/physician-fee-schedule/license-agreement.aspx. Accessed February 10, 2014. 25. Elliott LF, Eskenazi L, Beegle PH Jr, Podres PE, Drazan L. Immediate TRAM flap breast reconstruction: 128 consecutive cases. Plast Reconstr Surg. 1993;92:217–227. 26. Arnez ZM, Bajec J, Bardsley AF, Scamp T, Webster MH. Experience with 50 free TRAM flap breast reconstructions. Plast Reconstr Surg. 1991;87:470–478; discussion 479. 27. National Center for Health Statistics. Death in the United States, 2010. Available at: http://www.cdc.gov/nchs/data/ databriefs/db99.pdf. Accessed February 12, 2014. 28. Grosse SD. Assessing cost-effectiveness in healthcare: History of the $50,000 per QALY threshold. Expert Rev Pharmacoecon Outcomes Res. 2008;8:165–178. 29. Laupacis A, Feeny D, Detsky AS, Tugwell PX. How attractive does a new technology have to be to warrant adoption and
Volume 135, Number 3 • Mesh versus Primary Fascial Closure utilization? Tentative guidelines for using clinical and economic evaluations. CMAJ 1992;146:473–481. 30. Vernon JA, Payette M, Chatterjee A. Social welfare and adolescent vaccination programs in the United States: The economic opportunities for a systematic expansion. Soc Work Public Health 2009;24:414–445. 31. Davis Sears E, Chung KC. Decision analysis in plastic surgery: A primer. Plast Reconstr Surg. 2010;126:1373–1380. 32. Chen NC, Shauver MJ, Chung KC. A primer on use of decision analysis methodology in hand surgery. J Hand Surg Am. 2009;34:983–990. 33. Elwyn G, Edwards A, Eccles M, Rovner D. Decision analysis in patient care. Lancet 2001;358:571–574.
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34. Birkmeyer JD, Liu JY. Decision analysis models: Opening the black box. Surgery 2003;133:1–4. 35. Chatterjee A, McCarthy JE, Montagne SA, Leong K, Kerrigan CL. A cost, profit, and efficiency analysis of performing carpal tunnel surgery in the operating room versus the clinic setting in the United States. Ann Plast Surg. 2011;66:245–248. 36. Chatterjee A, Chen L, Goldenberg EA, Bae HT, Finlayson SR. Opportunity cost in the evaluation of surgical innovations: A case study of laparoscopic versus open colectomy. Surg Endosc. 2010;24:1075–1079. 37. Chatterjee A, Payette MJ, Demas CP, Finlayson SR. Opportunity cost: A systematic application to surgery. Surgery 2009;146:18–22.
Article Collections – Cosmetic Breast The Cosmetic Breast article collection on PRSJournal.com represents a pre-made article search on relevant topics in Cosmetic Breast, as evaluated and chosen by the PRS Editorial Board and the PRS Section Editors. The collection contains some of the most educational and very best articles published in Plastic and Reconstructive Surgery over the last 10 years. This is just one of 15 articles in the collection. See more at www.PRSJournal.com
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Background: During breast reconstruction using the transverse rectus abdominis myocutaneous (TRAM) flap, the use of mesh for abdominal donor-site closure provides for a technology that potentially offers clinical benefit yet incurs an added cost. The authors’ goal was to determine whether it is cost effective to use mesh during abdominal donor-site closure when performing a TRAM flap for breast reconstruction. Methods: A literature review was conducted to identify and collect published hernia and bulge rates at abdominal TRAM flap donor sites closed either primarily or with mesh. A decision tree analysis was performed. Outcome probabilities, costs of complications, and expert utility estimates were populated into the decision tree model to evaluate the cost-utility of using mesh in TRAM abdominal donor-site closure. One-way sensitivity analyses were performed to verify the robustness of the results. Results: The authors’ literature review resulted in 10 articles describing 1195 patients who had TRAM abdominal donor-site closure primarily and 696 patients who had donor-site closure performed with mesh. Pooled hernia/bulge complication rates for these two groups were 7.87 percent and 4.45 percent, respectively. The use of mesh was more clinically effective based on total quality-adjusted life-years gained of 30.53 compared with 30.41 when performing primary fascial closure alone. The incremental additional cost incurred by the mesh arm when running the decision tree model was $693.14. This difference in cost, divided by the difference in clinical efficacy (0.12), results in an incremental cost-utility ratio value of $5776.17 per quality-adjusted life-year gained when using mesh, making it cost effective (when using a willingness-to-pay threshold of $50,000). One-way sensitivity analysis revealed the following: (1) using mesh was a cost effective option, provided that the price of mesh was less than or equal to $5970; (2) mesh was cost effective when its use led to a hernia/bulge rate less than or equal to 7.25 percent; and (3) primary facial closure was cost effective when its use led to a hernia/bulge rate less than or equal to 4.75 percent. Conclusion: The use of mesh when repairing the abdominal donor site during a pedicled or free TRAM flap breast reconstruction is cost effective compared with primary fascial closure alone. (Plast. Reconstr. Surg. 135: 682, 2015.)
here has been substantial literature evaluating the clinical benefit of using mesh reinforcement versus primary fascial repair
From the Dartmouth-Hitchcock Medical Center. Received for publication May 30, 2014; accepted August 8, 2014. Presented at the 55th Annual Meeting of the New England Society of Plastic and Reconstructive Surgeons, in Sebasco Estates, Maine, June 6 through 8, 2014; and at Plastic S urgery The Meeting, in Chicago, Illinois, October 10 through 14, 2014. Copyright © 2015 by the American Society of Plastic Surgeons DOI: 10.1097/PRS.0000000000000957
682
of the abdominal donor site when performing a transverse rectus abdominis myocutaneous (TRAM) flap breast reconstruction.1–8 Although a perceived clinical benefit may exist in the use of mesh, the addition of this technology also adds a significant cost to the operation. This conflict of a Disclosure: Dr. Chatterjee is a speaker for LifeCell Corp. He has received no direct funding for this research project in particular. The other authors have no conflicts of interest to declare.
www.PRSJournal.com
Volume 135, Number 3 • Mesh versus Primary Fascial Closure technology offering a potential clinical advantage over the status quo while also potentially costing creates the need to perform a cost-utility analysis. This type of analysis weighs the clinical benefit and the added cost to assess whether a technology is cost effective compared with the status quo. To date, there has been no cost-utility study evaluating the use of mesh to reinforce the abdominal donor site when using a TRAM flap for breast reconstruction. Given this, our goal was to perform a cost-utility analysis to see whether there was a cost-utility benefit in using mesh (both synthetic and biological) versus primary fascial closure at the abdominal donor site in breast reconstruction patients undergoing TRAM flap surgery.
PATIENTS AND METHODS The use of mesh in the abdominal donor-site closure after TRAM flap harvesting for breast reconstruction has been well documented.1–8 As with the addition of any implantable material during an operation, the mesh may add not only clinical benefit but also increased cost. This perception of clinical benefit along with increased associated costs invites analysis that considers the relationship between cost and utilities. Cost-utility analysis is composed of costs, probabilities, and utilities of various health outcomes (health states) that are used to evaluate competing interventions.9–17 Perspective The perspective of the hospital was adopted for the decision analysis. Secondary data were used in this analysis for which it was impossible to estimate the productivity costs to the patient and the patient’s family; thus, adopting a societal perspective would be inappropriate.16,18 Health States The relevant surgical literature was explored to properly identify the most common and clinically pertinent abdominal donor-site mesh complications associated with free and pedicled TRAM flap breast reconstruction. These meshrelated complications primarily included abdominal bulge and hernia.1–8,19–22 Infections related to mesh were not included in the decision analysis, given that these complications were rare ( 0 and < willingness to pay, willingness to pay = $50,000. One-way sensitivity analysis was performed to determine whether the baseline decision analysis was robust by varying the hernia/bulge complication rate when using primary fascial closure and when using mesh and observing how this affected the incremental cost-utility ratio. One-way sensitivity analysis was also performed to calculate the maximum price of mesh that would allow it to be cost effective. All of the above statistical calculations were performed using TreeAge Pro 2012 (TreeAge Software, Inc., Williamstown, Mass.). This study was conducted in accordance with the principles outlined in the Declaration of Helsinki.
RESULTS The literature review1–8,19–22,25,26 revealed that the complication rate was heavily dominated by abdominal hernia/bulges with and without the use of mesh when repairing the abdominal donor site after TRAM flap harvest (Table 1). When performing primary closure of the abdominal donor site, the abdominal hernia/bulge rate was 7.87 percent versus 4.45 percent when using mesh as a reinforcement. The cost-utility analysis revealed a baseline cost difference of $693.14, a gain in quality-adjusted life-years of 0.12, and an incremental cost-utility ratio of $5776.17 per quality-adjusted life-year gained with the use of mesh closure compared with primary fascial closure (Table 2). This is substantially less than the $50,000 threshold (marking the upper limit of willingness to pay), making the use of mesh a cost-effective option. One-way sensitivity analysis (Table 2) performed by varying mesh pricing while holding other variables constant revealed that using mesh
685
Plastic and Reconstructive Surgery • March 2015 Table 2. Cost Utility and Sensitivity Analysis
Baseline analysis Sensitivity analysis (when using mesh) Recurrence rate (with mesh) = 7.25% Sensitivity analysis of maximum mesh cost Cost of mesh = $5970
Cost Difference ($)
QALY Gained
Cost ($) per QALY Gained (ICUR)
693.14
0.12
5776.17
739.54
0.02
36,977.00
5913.14
0.12
49,276.17
QALY, quality-adjusted life-year; ICUR, incremental cost-utility ratio.
to repair the abdominal donor site was a cost-effective option, provided that the price of mesh was less than or equal to $5970. Similarly, one-way sensitivity analysis (Table 2), performed by varying abdominal hernia/bulge rates when using mesh, revealed that the use of mesh during TRAM flap abdominal donor-site closure is cost effective when its use leads to a hernia/bulge rate less than or equal to 7.25 percent. A hernia/bulge rate of greater than 7.25 percent, when using mesh, led to a qualityadjusted life-year gained of greater than $50,000, thus making it cost-ineffective. Lastly, one-way sensitivity analysis revealed that when all other variables are held constant, primary facial closure of the abdominal donor site is cost effective when its use leads to a hernia/bulge rate less than or equal to 4.75 percent.
DISCUSSION The difficulty of assessing an intervention that improves clinical outcomes yet adds cost to the health care system is an area of study in which cost-utility analysis proves most useful.18 Within the arena of cost analysis, cost-utility analysis studies the clinical outcomes of a surgical intervention and translates it into quality-adjusted life-years. These quality-adjusted life-years are then compared to the costs of the surgical intervention to create a cost per quality-adjusted life-year, also known as the incremental cost-utility ratio.16,18 This ratio provides the marginal cost incurred by a new intervention per quality-adjusted life-year gained. The decision to choose this newer or alternative intervention is based on a predetermined, acceptable upper cost limit per quality-adjusted life-year. Ranges in the literature between $20,000 and $150,000 per quality-adjusted life-year have been proposed, depending on which health care system or payer group is involved.29,30 Our threshold for cost-effectiveness at $50,000 per quality-adjusted life-year was chosen based on historical precedent.28 This number was felt to be a conservative estimate for the maximum willingness of a society to pay based on both domestic and international standards.30
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Based on our results, the use of synthetic mesh is a cost-effective option when closing the abdominal donor site of the TRAM flap being used for breast reconstruction. The incremental cost-utility ratio value of $5776.17 per qualityadjusted life-year gained demonstrates that the cost effectiveness of using mesh is derived from the decreased hernia rate of 4.45 percent with its use. This increased clinical benefit makes the additional cost of the mesh acceptable. These findings support the use of mesh at the abdominal donor site and provide a cost-outcomes conclusion. Our literature review demonstrated that by far the most prevalent TRAM flap donor-site complication is abdominal hernias/bulges (Table 1). Although other donor-site complications are associated with TRAM flap breast reconstruction, the purpose of this study was to look at a decision analysis focusing on whether or not to use mesh in repairing the abdominal donor site. For this reason, complications such as hematomas, seromas, and abdominal wall weakness were not included in the decision analysis. Our literature review did not show that these complications were specifically associated with the use of mesh; thus, they were not included in this particular decision analysis. Sensitivity Analysis Our one-way sensitivity analysis (Table 2) revealed that by varying the probability of an abdominal hernia/bulge complication occurring with the use of mesh, a probability of 0.0725 (7.25 percent) or lower was associated with increased cost-effectiveness of using mesh. Certain assumptions were made, including the maximum willingness-to-pay amount for a quality-adjusted life-year was $50,000, the distribution of specific complications remained constant, and the complication rate of primary fascial closure remained constant at 7.87 percent. If one were to prefer to use a primary fascial closure technique for the abdominal donor site, our sensitivity analysis revealed that by varying the probability of an abdominal hernia/bulge complication occurring with primary fascial closure alone, a probability of 0.0475 (4.75 percent) or lower was
Volume 135, Number 3 • Mesh versus Primary Fascial Closure associated with increased cost-effectiveness without using mesh. Again, similar assumptions were made, namely, that the complication rate of closure with mesh remained constant at 4.45 percent. Lastly, a one-way sensitivity analysis was performed by varying the price of mesh and holding other variables constant, and demonstrated that the maximum cost-effective price of mesh was $5970 or less. Mesh Choice and Surgeon Autonomy The use of cost-effectiveness analysis in decision making should be studied collaboratively by decision makers and analysts to improve its usefulness. In cost-conscious times, especially during an economic recession where health care cost cutting threatens to undermine the autonomy of surgeon choice, cost-utility analysis provides the surgeon an empowering tool that validates clinical judgment. An example of this is demonstrated by the one-way sensitivity analysis that finds the maximum price of mesh to be $5970 at or under which choosing mesh would be a cost-effective option. With this knowledge, the surgeon can justify the clinical benefit and cost of mesh choice, synthetic or biological, when repairing an abdominal TRAM flap donor site. Although the literature demonstrates clinical benefits of using either synthetic or biological mesh, there is no head-to-head comparison of the two when closing an abdominal donor site. However, this cost-utility with its sensitivity analysis justifies the use of either, provided that the cost of the mesh being used is $5970 or less. Limitations One limitation inherent in cost-utility analysis is its reliance on the reliability of the literature in the literature review.31–34 Factors such as chemotherapy were not addressed in the articles reviewed and can present as confounders to outcomes with regard to donor-site healing. In addition, there is an assumption that the data gathered with regard to surgical technique and outcomes when performing TRAM flap operations and the closure of abdominal donor sites is uniform with little variability. Clearly, inherent flaws are present when pooling data from a literature review, given the variability of data collection, patients being operated on, and surgeons performing the operations. One example of this is highlighted by the variability of follow-up periods in the literature. Hernias and bulges can present several years after an operation. By pooling data that represent a sample of patients with follow-ups ranging from 6 months to 6 years, hernias and bulges in this
sample could have been missed if they presented at later times. Until further large-scale, prospective, randomized, unbiased studies are performed, the decision analysis performed here provides a reasonable cost-effectiveness analysis that can aid in decision making when it comes to using or not using mesh to close TRAM flap donor sites. A second limitation involves the assumption that no subsequent recurrences of hernia/bulges occurred after the first revision. By relying on the literature specific to TRAM flap donor-site reconstruction, we modeled our outcomes to what was reported in the literature, which did not assume subsequent recurrences. This may have been attributable to the follow-up period, which may have missed subsequent hernias and bulges. A third limitation involves the grouping of mesh in the literature review that includes both biological and synthetic mesh. On further reviewing the individual articles used, there was no observable difference in hernia/bulge complication rates between biological and synthetic mesh.1,19 This may be because the abdominal donor sites still have some sort of fascia (either rectus sheath or transversalis fascia) remaining over which the mesh supplements and adds strength to the closure. The preference of using one type of mesh over another for abdominal donor-site closure, which constitutes an area for potential future research, is beyond the scope of this article, which compares mesh use to primary fascial closure. A fourth limitation involves the choice of TRAM flaps for breast reconstruction versus other forms of autologous tissue for breast reconstruction. The choice of considering the TRAM flap (free and pedicled) was made because of its common use in breast reconstruction and the abundance of literature available looking at outcomes from this operation. Although other flaps such as the muscle-sparing TRAM flap and the deep inferior epigastric perforator flap are reasonable options for breast reconstruction, the results of this study do not directly address the use of mesh in these types of reconstructions. A fifth limitation involves the inherent lack of opportunity cost in a decision tree analysis. Opportunity cost is the potential gain or loss when a person chooses to perform an activity over its next best alternative.35–37 With respect to surgery, opportunity cost can occur if a less efficient surgical technique uses more overall operating time (by possible complications incurred requiring further operations) than its next best alternative. This additional operating time could be used in a productive way that, when economically valued,
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Plastic and Reconstructive Surgery • March 2015 adds a “cost” to the less efficient surgical technique. In our decision analysis, not using mesh may lead to additional bulges and hernias that adds an expense in time that could otherwise be used productively in performing other operations.
CONCLUSIONS The use of mesh, biological or synthetic, when repairing the abdominal donor site during a pedicled or free TRAM flap breast reconstruction can be cost-effective when compared with primary fascial closure alone. The use of mesh remains a costeffective option, provided that the hernia/bulge recurrence rate with its use remains less than or equal to 7.25 percent or its costs are less than or equal to $5970. If one chooses to use primary closure alone to repair an abdominal donor site, the hernia/bulge rate should be less than or equal to 4.75 percent for this approach to be cost-effective. Abhishek Chaterjee, M.D., M.B.A. Dartmouth-Hitchcock Medical Center One Medical Center Drive Lebanon, N.H. 03756 [email protected]
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Article Collections – Cosmetic Breast The Cosmetic Breast article collection on PRSJournal.com represents a pre-made article search on relevant topics in Cosmetic Breast, as evaluated and chosen by the PRS Editorial Board and the PRS Section Editors. The collection contains some of the most educational and very best articles published in Plastic and Reconstructive Surgery over the last 10 years. This is just one of 15 articles in the collection. See more at www.PRSJournal.com
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