“Locus minoris resistentiae” and connective tissue weakness in older women: a case report and review of the literature on pelvic organ prolapse with inguinal bladder hernia | BMC Women’s Health
In all three cases reported here, the patients were of advanced age and long postmenopausal. In the context of demographic development in industrialized countries, many elderly people are in good general condition and have high expectations for their quality of life. Thus, we find it important to discuss surgery in the context of advanced age and aging.
In two of the cases presented here, MIII inguinal hernias developed or significantly enlarged after reconstructive surgery for POP. A patient presented with the triple finding of POP, rectal prolapse and inguinal hernia. In all cases, ultrasound examination revealed that the hernial sacs contained the bladder, which had herniated through the orifice of the inguinal hernia.
Inguinal bladder hernia is rare . Levine  first described it in 1951, using the term “scrotal cystocele”. It usually occurs in men with other risk factors, such as obesity and / or age> 50 years . Less than 7% of these hernias are diagnosed before surgery because of their asymptomatic presentation or nonspecific symptoms, such as hematuria, dysuria, urgent urination, and inguinal swelling . The literature contains several case reports and case series of inguinal hernia of the bladder in humans. [2, 3]. Alsayegh et al.  reported that approximately 150 such cases had been reported up to 2004. Branchu et al.  included 64 cases of inguinal bladder hernia in men in their systematic review covering the period 2005-2017. A case of indirect inguinal bladder hernia in a patient, detected post-mortem, was reported by Tubbs et al. . A search of the PubMed database using the terms “inguinal hernia” AND “bladder” AND “female” or “inguinal bladder hernia” AND “female” revealed an additional case of direct inguinal bladder hernia in a 72-year-old female. years, reported in 2018 by Caliscan et al. . In two of our presented cases, a hernia had developed or enlarged following reconstructive surgery for POP due to several conditions and anatomical musculo-aponeurotic weakness – a “locus minoris resistentiae”.
Although reports of this type of bladder hernia are rare , simultaneous discovery of inguinal hernia and POP may be more common, as both conditions are considered to be associated with connective tissue weakness [12, 13]. Few studies of POP risk constellations have examined this simultaneous presentation [5, 9,10,11]. Risk factors for POP include menopause, advanced age, a high body mass index, a difficult obstetric history, spontaneous vaginal deliveries, heavy labor, a family history of prolapse, and signs of connective tissue disorders ( for example, varicose veins, hemorrhoids and hernia) [8, 9]. Previous hernia surgery was only considered in one of the studies included in a review of risk factors for POP and its recurrence; the authors thus stated that this factor could not be associated with primary POPs without additional confirmatory evidence . However, in a cross-sectional study of 1380 women in the Netherlands, a previous surgery for POP and / or incontinence was associated with a previous surgery for hernia. . A case-control study showed that inguinal hernia was significantly more common in 60 patients with advanced POP (stage III-IV) than in 60 patients without POP or mild (stage 0-I) . However, complete data on the coexistence of hernia and female genital prolapse remains scarce.
A historical review of the literature for the past 40 years has confirmed that similar pathophysiological mechanisms underlie POP, inguinal hernia, and abdominal wall abnormalities called “herniosis”, which may be responsible for the co-occurrence of the conditions. [11, 21]. A growing number of studies have found collagen alterations associated with POP and hernia [12, 13]. Changes in the amount and ratio of collagen subtypes I and III, the biomechanical properties and structure of collagen fibrils, and abnormalities in collagen catabolism, caused for example by imbalances in matrix metalloproteinases and inhibitors tissue metalloproteinases have been described. [12, 13]. Additionally, alterations in the collagen gene have been associated with the development of inguinal hernia and POPs. [13, 22, 23]. The aging of tissues is believed to be an important endogenous trigger for both conditions [9, 24].
The simultaneous occurrence of hernia and female genital prolapse can also be conceptualized according to the “locus minoris resistentiae” model. This model is used in various fields of medicine, such as dermatology and internal medicine [14, 25]. Siegfried’s shoulder and Achilles heel are the original examples of “locus minoris resistentiae” from Greek mythology. . In medicine, the term refers to any part of the body that is more vulnerable than other areas to disease due to impaired firmness. . In anatomy, it describes regions of the musculo-aponeurotic system with less resistance, leading to a hernia, such as the female pelvic floor and inguinal canal . In our cases, the bladder had found its way to a second “locus minoris resistentiae” after the first of these sites had been surgically closed.
In summary, although reports of inguinal bladder hernia in women are rare, the simultaneous occurrence of hernial orifices and POPs may be more common, as evidence suggests that hernia and POP coexist frequently. [4, 9,10,11] and that similar collagen alterations underlie both conditions [12, 13]. With this report, we present our observations on a small sample of cases of this rare disease. A larger prospective study on the subject using the “locus minoris resistentiae” model to examine detailed preoperative and follow-up information on patient history, risk factors for POP or hernia and individual complaints is warranted. With additional evidence, the simultaneous discovery of hernia and POP could be further discussed as a valid clinical marker for the future definition of connective tissue weakness for clinical evaluation..
The simultaneous occurrence of an inguinal hernia and a female POP can lead to a bladder hernia after prolapse surgery, in the sense of “locus minoris resistentiae”. Clinical examination of simultaneous signs of connective tissue weakness and counseling before pelvic reconstructive surgery may help increase patients’ adherence to subsequent surgical treatment of the hernia.