Assignment 1 - Part 1

Name Study Number Bachelor Study E-mail

: : : :

Dwisetya Safirna Widyaratih 4491408 Mechanical Engineering [email protected]

Part I: Transvaginal Mesh for Reconstructing Pelvic Organ Prolaps (POP) Pelvic Organ Prolapse (POP) is the condition when the pelvic organ descended from its normal position (herniation) due to weakening of muscles, ligament, or fascia that support the organ. There are three types of POP (figure 1), which are anterior compartment prolapse, posterior compartment prolapse, and uterine prolapse [1]. There are several ways to treat POP, depend on severity of the prolapse. In the early stage of POP, the patient can be treated with non-surgical option by doing kegel exercise to strengthen pelvic muscle. The other treatment is inserting ring pessary to support the organ. If the POP is getting worse, doctor will offer a surgical treatment. If the patient is not sexually active anymore, the doctor usually recommends vaginal closure surgery (Colpocliesis). In the other hand, for a sexually active woman, the doctor will do a reconstructive surgical repair by inserting a surgical mesh to support the organ to reconstruct the organ and retaining the sexual function (figure 2A &B).

Figure 1Pelvic Organ Prolapse Types [1]

For the past years, surgical mesh has been widely used to reconstruct the pelvic floor (transvaginal mesh). In the Netherlands more than 13,000 surgical procedures each year

have been performed to correct POP [2]. Transvaginal mesh has a relatively easy procedures to be inserted in the body and provides a good anatomical result. It is made from polypropylene, polytetrafluoroethylene, or polyester fibers. Surgical mesh was firstly used to treat abdominal hernias in the 1950s. Then, in 1970s, another functionality of abdominal surgical mesh was induced to correct POP. The first surgical mesh product intended for vaginal was approved by FDA in 2002 [3]. This reconstructive surgery for POP is an incision surgery. The surgeon use 3 main tools, which are anatomic curvature, retrieval device, and cannula (figure 2C). Firstly, incision is proceed by anatomic curvature and cannula. The incision starting point is 3cm below and 3cm lateral from anus. Surgeon hand guide the direction of the tools to pass through the sacrospinous ligament and enter rectovaginal space. Next, the anatomical guideline is carefully removed and leave the cannula inside to hold its position. The retrieval device is inserted via cannula and retrieve from rectovaginal space. The retrieval device is pulled out from vagina therefore it has two ends, one is from vagina and the other is from cannula. The last step is inserting the transvaginal mesh. The transvaginal mesh is tied to the retrieval device that come out from the vagina. The retrieval device is pulled from the other end, resulting the transvaginal mesh pass through the vaginal space, cannula, and retrieve in incision point. Then the cannula is removed, leaving the transvaginal mesh inside the body. For a complete animation of the surgery, access https://www.youtube.com/watch?v=LBSh-VLuid4.

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B

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Figure 2 (A & B) Transvaginal Mesh Inside Body [4] [5], (C) Surgical Tools (Gynocare Prolift, Johnson & Johnson Brand)

However, reconstructive surgery didn’t seem to remedy the patients. The transvaginal mesh is intended to be permanently hold the prolapse. After few years of implantation, there are several complications of transvaginal mesh. If we look at the history of transvaginal mesh, this product was not exactly designed for pelvic floor. It based on the characteristics of abdominal hernia meshes. The complication occurred because vagina have completely different biomechanical properties than the abdominal wall [6]. Moreover, the other problem of transvaginal mesh can result from degradation of mesh’s material as a result of it is not inert and not biocompatible. As consequence, the material will degrade and become brittle. It will produce toxic compound and restricts movement in pelvic area, increases the risk of

inflammatory and erosion [6] [7]. This oxidation process and will occur continuously in patient for lifetime. It will become more and more painful for the patient so the surgeon must do another operation for revision surgery to remove the mesh. In July 2011, FDA (Food and Drug Administration) warned of serious complications associated with pelvic reconstruction surgery using transvaginal mesh. They received nearly 4,000 complaints between 2005 and 2010. About 75,000 women filed lawsuits against the manufacturers of transvaginal mesh products [3]. Facing lots of complaints and dead ends in conventional transvaginal mesh, researcher start to evaluate the material of transvaginal mesh. The researcher need to discover a new technological solution from engineering science. The failure of transvaginal mesh arise from the selection of material. There are many choices in degradable material but it will just hold the organ for the period of time. Another reconstructive surgery still have to be done to insert a new mesh. The most suitable material for permanent usage of transvaginal mesh is titanium (Ti). Titanium has been commonly used for implant. It is biocompatible, nontoxic, and corrosion resistance. It can be equipped in the pelvic for permanent use without any complication. But how to insert the titanium in the organ without an open incision? How does the titanium passing through the cannula? The best solution is using nitinol as the material of the transvaginal mesh. Nitinol is a unique material that formed from titanium and nickel (Ni). It has a superelastic and shape memory behavior. The performance of nitinol is undoubtedly, it has been extensively exploited by medical device industry since the late 1980’s [8]. The shape and geometry of nitinol transvaginal mesh duplicate the conventional transvaginal mesh. The procedures of insertion is the same as well. It is also uses anatomic curvature, retrieval device, and cannula. Nitinol can be flexible enough for insertion through the cannula. After inserting the nitinol mesh inside the cannula, it will recover from the deformation and fit in the pelvic organ properly. Another benefit of using nitinol as transvaginal mesh is MRI compability. It is safe to perform MRI for the patient. This imaging can be used for evaluation after the surgery and controls the patients’ condition.

I hereby state that this essay contains my own ideas and it was written by myself.

[1] [2] [3] [4]

[5] [6] [7] [8]

I. U. Association, "Pelvic Organ Prolapse: A Guide for Women," 2011. A. Vollebregt, Polypropylene Mesh in Anterior Vaginal Prolapse Surgery : Efficacy, Safety, and Cost, Waddinxveen: Off Page, 2012. "Drug Watch," 2015. [Online]. Available: http://www.drugwatch.com/transvaginal-mesh/. [Accessed 24 October 2015]. A. L. F. Association, "Transvaginal Mesh Settlement," [Online]. Available: http://www.transvaginalmeshsettlement.com/legal-options-transvaginal-mesh/what-is-transvaginal-mesh/. [Accessed 24 October 2015]. "Injury Lawyer News," 19 August 2014. [Online]. Available: http://injurylawyer-news.com/transvaginalmesh/stress-urinary-incontinence/. [Accessed 24 October 2015]. Expert Report of Prof. Dr. Med Bernd Klosterhalfen, M.D., 2015. D. Ostergard, "Polypropylene vaginal mesh grafts in gynecology.," The American College of Obstetricians and Gynecologists, vol. 116, no. 4, pp. 962-966, 2010. P. P. Poncet, "Application of uperelastic Nitinol Tubing," MEMRY Corporation, California.