A Pathology of Mesh and Time: Dysejaculation, Sexual Pain, and Orchialgia Resulting From Polypropylene Mesh Erosion Into the Spermatic Cord.

OBJECTIVE: The ubiquitous use of polypropylene mesh in hernia surgery has spawned a new clinical syndrome: chronic post-herniorrhaphy neuralgia. A subset of that clinical picture is dysejaculation, sexual pain, and orchialgia. We propose to identify the processes that lead to that pain. SUMMARY OF BACKGROUND DATA: Specimens of vas adherent to polypropylene mesh, explanted in an attempt to control severe, life-changing inguinodynia are extremely difficult to obtain. This scarcity may be due to ingrained attitudes in our society about removal of vas and/or testicles for whatever reason. Attempts at preserving such damaged structures may paradoxically contribute to the chronicity and severity of such pain. METHODS: The medical files of patients who had mesh specimens explanted because of severe chronic post-herniorrhaphy pain were reviewed to identify cases with recorded evidence, at the time of surgery, of involvement of spermatic cord/vas deferens with mesh. These criteria were met in 13 cases and the specimens were analyzed histologically. RESULTS: The vas deferens was resected in 83% (5 of 6) of the patients with a history of sexual pain and/or dysejaculation (vs 14% of those without a history of sexual pain, P = 0.03). Histology demonstrated unequivocal mesh invasion of the spermatic cord, where the initial damage occurred to nerves (autonomic, somatic), then to the smooth muscle of the vas while the lumen remained patent. In 50% (3 of 6), the vas and other cord structures appeared to be completely invaded by the mesh and replaced by scar tissue. CONCLUSIONS: Irreversible damage of the nerves and vas musculature due to mesh migration is one of the mechanisms for sexual pain and dysejaculation. Attempts at all cost to preserve elements of the spermatic cord may not be justified in cases of severe pain, especially sexual pain (and/or dysejaculation) and intraoperative finding of cord involvement by the mesh. Vasectomy with mesh removal may well be indicated and be considered not a radical procedure but a conservative measure given the severity of the pain!

Degradation of polypropylene in vivo: A microscopic analysis of meshes explanted from patients.

Polypropylene meshes, originally introduced for hernia repair, are presently utilized in several anatomical sites. Several million are implanted annually worldwide. Depending on the device, up to 10% will be excised to treat complications. The excised meshes can provide material to study the complications, however, they have remained underutilized over the last decades and the mechanisms of complications continue to be incompletely understood. The fundamental question as to whether polypropylene degrades in vivo is still debated. We have examined 164 excised meshes using conventional microscopy to search for features of polypropylene degradation. Four specimens were also examined by transmission electron microscopy. The degraded material, detected by its ability to absorb dyes in the degradation nanopores, formed a continuous layer at the surface of the mesh fibers. It retained birefringence, inclusions of non-degraded polypropylene, and showed ability to meld with the non-degraded fiber core when heated by the surgical cautery. Several features indicated that the degradation layer formed in vivo: inflammatory cells trapped within fissures, melting caused by cautery of excision surgery, and gradual but progressive growth of the degradation layer while in the body. Cracking of the degraded material indicated a contribution to clinically important mesh stiffening and deformation. Chemical products of degradation need to be analyzed and studied for their role in the mesh-body interactions. The described methods can also be used to study degradation of other materials. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 237-248, 2017.

Safety considerations for synthetic sling surgery.

Implantation of a synthetic midurethral sling (SMUS) is the most commonly performed anti-incontinence operation in women worldwide. The effectiveness of the SMUS is comparable to that of the historical gold standards--autologous fascial slings and the Burch colposuspension. Much controversy, however, has evolved regarding the safety of this type of sling. Overall, the quality of the studies with respect to assessing risks of SMUS-associated complications is currently poor. The most common risks in patients with SMUS include urethral obstruction requiring surgery (2.3% of patients with SMUS), vaginal, bladder and/or urethral erosion requiring surgery (1.8%) and refractory chronic pain (4.1%); these data likely represent the minimum risks. In addition, the failure rate of SMUS implantation surgery is probably at least 5% in patients with stress urinary incontinence (SUI). Furthermore, at least one-third of patients undergoing sling excision surgery develop recurrent SUI. Considering the additional risks of refractory overactive bladder, fistulas and bowel perforations, among others, the overall risk of a negative outcome after SMUS implantation surgery is ≥15%.

Femoral pseudo-hernias.

Before surgical intervention in the femoral area, doctors should be mindful of two situations in which surgery is not indicated and, in fact, may cause harm.

The unified theory of hernia formation.

The perusal of surgical journals suggests that the etiology and the treatment of hernias are still based on the understanding of a simple mechanical defect, an idiopathic happenstance requiring a reliable hernia repair, preferably with a prosthetic mesh or device. The need for additional elucidation does not constitute an aim that is pervasive in the surgical community or with the corporate manufacturers of surgical implements. This may well be because surgeons are not trained scientists and laboratory workers. Fortunately, several disciplines are injecting a healthy dose of curiosity matched by ingenuity. Among these contributors, we can count anatomists, electron microscopists, biochemists, organic chemists, pathologists, geneticists, and molecular biologists, who have looked at collagen, enzymes, tobacco smoke, congenital diseases, and chromosomal defects. Every aspect of the researchers' work has identified and converged onto a final common organ: collagen. It is the pathological changes in collagen that set the stage for the development of a hernia. The multiple theories on mechanisms of hernia formation have, at last, melded into one single Unified Theory of hernia formation.