Pelvic Floor Disorders: Surgical Approach

2. Epidemiology and Prevalence of Pelvic Floor Disorders

Carolina Ilaria Ciangola, Ilaria Capuano, Federico Perrone and Luana Franceschilli 

(1)

Department of Experimental Medicine and Surgery, Tor Vergata University, Rome, Italy

Luana Franceschilli

Email: luana.franceschilli@virgilio.it

Abstract

Pelvic floor disorders (PFDs) manifest with a variable spectrum of symptoms and can involve anterior, middle and posterior compartments. PFDs represent an important aspect of global healthcare, with about 28 million women affected by these diseases worldwide. This number is expected to reach 44 million in the next 40 years. In the literature, the incidence and prevalence of PFDs are often reported inconsistently, depending on the definitions used, the measures considered to assess the stages, the gender and age of the patient, and the severity of the pathology. The etiology of these disorders is multifactorial and it is important to identify the risk factors, because avoiding them or reducing exposure to them can change the natural history of PFDs, allowing physicians to make an earlier diagnosis and use more effective therapy.

2.1 Introduction

Pelvic floor disorders (PFDs) manifest with a variable spectrum of symptoms and can involve anterior, middle and posterior compartments. PFDs represent an important aspect of global healthcare, with about 28 million women affected by these diseases worldwide. This number is expected to reach 44 million in the next 40 years. In the literature, the incidence and prevalence of PFDs are often reported inconsistently, depending on the definitions used, the measures considered to assess the stages, the gender and age of the patient, and the severity of the pathology. The etiology of these disorders is multifactorial and it is important to identify the risk factors, because avoiding them or reducing exposure to them can change the natural history of PFDs, allowing physicians to make an earlier diagnosis and use more effective therapy.

2.2 Definitions, Costs, and Prevalence of Pelvic Floor Disorders

Pelvic floor disorders (PFDs) manifest with a variable spectrum of symptoms and can involve the anterior, middle, and posterior compartments of the pelvic floor. PFDs can manifest as:

·               Urinary incontinence and sensory abnormalities of lower urinary tract

·               Pelvic organ prolapse

·               Anal incontinence

·               Obstructed defecation

·               Chronic pain syndromes related to the pelvic organs

PFDs represent an important aspect of global healthcare, with an incidence of about 4 million visits per year to physicians in the USA (1% of total ambulatory visits). In 1997, costs of pelvic organ prolapsed (POP) surgery in the USA were US$1,012 million, including US$494 million for vaginal hysterectomy, US$279 million dollars for cystocele and rectocele repair, and US$135 million for abdominal hysterectomy. Moreover, costs for physician services and hospitalization increase the total expense. An indirect expense is represented by days absent from work due to illness [1].

The incidence of PFDs is increasing: 48,000 surgical procedures for urinary incontinence (UI) were performed in 1979, and over 100,000 were performed in 2004 [2]. For a woman aged 80 years, the lifetime risk of undergoing surgery for PFD is 11% [3]. Annually, in the USA, 80,000 surgical procedures are performed for UI, 220,000 for POP, and 3,500 for fecal incontinence. The following rates have been reported for age distribution of surgical treatment: 7, 24, 31, and 17 per 10,000 in reproductive, perimenopausal, postmenopausal, and elderly women, respectively [4].

It is thought that these numbers will increase, as the number of women expected to develop PFD increases in future decades. At present, the number of women affected by PFDs is about 28 million, and this number is expected to reach 44 million in the next 40 years. Moreover, the prevalence of PFD increases as the average age of the women increases; the percentage of PFD recurrence (currently 30%) also increases with age [5].

In the scientific literature, reports of the incidence and prevalence of PFD can be inconsistent, depending on the definitions used, the measures considered to assess the stages of PFD, the gender and age of the patient, and the severity of the pathology. Globally, we can assume that the prevalence of PFD may vary from 37% to 68% [6]. The National Health and Nutrition Examination Survey (NHANES) estimated that 24% of adult women experienced PFD symptoms. This prevalence increased with age: about 38% of women aged 60–79 years, and about 50% of women aged 80 years, were affected by PFD. In 2010, about 28 million people had a PFD in the USA.

2.3 Pelvic Floor Disorders

In order to increase our knowledge of the pathology of PFDs and their real impact on the global population, it is important to analyze the prevalence and incidence of each of the various manifestations of PFD.

2.3.1 Urinary Incontinence

The International Continence Society defined UI as “the complaint of any involuntary leakage of urine”. A review of 21 studies revealed a prevalence of 34% for any incontinence. Younger women are more affected by stress incontinence, while older women are affected by mixed and urge incontinence. Some studies have not found any relationship between ethnic origin and incidence of UI [7], while other studies on the USA population have found that 36% of Hispanic, 30% of white, 35% of black, and 19% of Asian American women experienced UI [8].

2.3.2 Pelvic Organ Prolapse

POP is defined as the complex of rectocele, cistocele and uterine prolapse. Based on a study conducted by Women’s Health Initiative [9], the general prevalence of POP is thought to be 41%. Further distinguishing between the different clinical manifestations of POP, the prevalence of cystocele varies from 25% to 34%, that of rectocele from 13% to 19%, and that of uterine prolapse from 4% to 14%, considering any grade of prolapse.

2.3.3 Anal Incontinence

Anal incontinence (AI) is defined as involuntary passage of gas, mucus, or liquid or solid feces. In the literature, the reported prevalence of AI varies from 2% to 24%, depending on the different definitions used for AI in scientific papers. Age is a risk factor for AI and an increase in adds ratio of 1.20 has been demonstrated for an increase of 10 years in age. According to scientific data, ethnicity does not appear to be a relevant factor in AI [2].

2.3.4 Obstructed Defecation

Obstructed defecation (OD) is defined as a persistent, difficult, infrequent, and incomplete evacuation. The prevalence of OD is 2–30% in the general population. OD can be caused either by slow intestinal transit and functional abnormalities, such as dyssynergic contraction of the pelvic floor muscles, which are more frequent in younger women, or by structural abnormalities of the pelvic floor, such as rectal prolapse and rectocele, which are more frequent in older women. It is important to distinguish between various causes of OD, as they can be treated differently [10].

2.4 Risk Factors

The etiology of these PFDs is multifactorial. Multiple genes, clinical history, comorbidities, and environmental risk factors, such as drugs, diet, and lifestyle, and the association between them, contribute to the development of PFDs.

It is important to identify the risk factors because avoiding them or reducing exposure to them can change the natural history of PFDs, allowing clinicians to make an earlier diagnosis and use more effective therapy. It is possible to divide the risk factors into different categories:

·               Predisposing factors: these are not modifiable

·               Inciting factors: theoretically these can be modified, but often they cannot be avoided

·               Promoting factors: these are easily modifiable and can influence the natural history of PFD

·               Decompensating factors: these are extrinsic to the pelvic floor but can create decompensation and dysfunction of an otherwise compensated pelvic floor.

2.4.1 Predisposing Factors

These include genetic make-up, congenital factors, race, age, and anatomic, neurologic and muscular factors. Although specific genetic loci responsible for the development of these pathologies are unknown, pelvic floor dysfunctions are more likely to be present in some genetic syndromes, especially in collagen diseases such as Ehlers-Danlos and Marfan syndromes. Moreover, it has been demonstrated that women with POP have more type III collagen in their pelvic floor tissue [11]. Cases of neonatal prolapse have been described, sometimes in association with neural tube abnormalities such as spina bifida, but also in neurologically intact neonates, underlining the possible role of undernutrition in utero [12]. Some research publications have shown that there is a increased incidence of pelvic floor dysfunctions in white American women compared with African American women, who have a smaller posterior pelvic floor area [13], narrower pelvic inlet and outlet [14], and higher urethral closing pressure while contracting pelvic muscles [15], suggesting an important role of race and ethnicity in the development of these disorders. Some women with POP have been demonstrated to have denervation of levator ani and periurethral muscles and altered neuropeptide function [2]. Finally, aging seems to be a complex risk factor, as it allows other risk factors to act over a longer period of time and result in a PFD [16].

Female gender is also a predisposing risk factor, but men are also affected by pelvic organ disorders: the male to female ratio for rectocele is 1:10 and the prevalence reported in literature [17], although scant, varies from 4% to 17%. Rectocele in men is more often associated with aging and prostatectomy (40%), although precise criteria for diagnosis of male perineal prolapse are yet to be formulated.

2.4.2 Inciting Factors

Inciting factors for PFDs include childbirth, radiation, and pelvic surgery. Various studies have analyzed the role of pregnancy and modes of delivery in the development of PFDs. PFDs increase with the number of deliveries: 30% of women who have had three or more deliveries develop PFDs [7]. However, when considering the mode of delivery, vaginal parous women show a greater prevalence for PFDs compared with nulliparous and cesarean parous women. There is no difference in the incidence of PFDs between nulliparous and cesarean parous women, but when further distinguishing between gravid nulliparous (women who had a pregnancy but did not deliver an infant larger than 2 kg) and nulligravid nulliparous women, the former show a higher prevalence for PFDs and this indicates an important role for hormonal factors in the development of PFDs. Further distinguishing between cesarean deliveries with and without labor, there is a greater prevalence of PFDs in women who had a labor, underlining the importance of mechanical stress on the pelvic floor [18]. Studies analyzing the incidence of POP in nulliparous and parous sisters demonstrated a similar rate of prolapse between the two, indicating a strong familial predisposition [5]. It is important to remember that environmental factors such as childbirth should be considered together with genetic susceptibility, as prolapse often occurs many years after delivery; however, the majority of women who have delivered do not experience PFDs and some women who have not delivered develop PFDs [5].

2.4.3 Promoting Factors

Promoting factors include constipation, body mass index (BMI), increased waist circumference, smoking, comorbidities, occupational activities, medications, infections, and hormonal therapy. Chronic constipation is controversially associated with POP, although it seems to create injuries to sphincteric innervation. Of patients undergoing surgery for rectal prolapse, 80% experienced an improvement in defecatory function. A waist circumference of more than 88 cm is associated with an increased risk of developing POP, as there is an increase in mechanical stress on the pelvic floor [19]. Obesity causes an increase in intra-abdominal pressure and women with a BMI of greater than 25 have a 30-50% higher risk of developing a PFD. Moreover, women who have undergone bariatric surgery and then lost 18 or more BMI points improved their urinary incontinence symptoms [20]. Anorexia is another risk factor for PFDs: 81% of anorexic patients reported defecatory disorders that increased with the duration and severity of the eating disorder, probably because of prolonged attempts to defecate, use of laxatives, overzealous exercise, and increased intra-abdominal pressure from forced vomiting [21]. The association between anorexia nervosa and rectal prolapse may be much more common than previously recognized. The Epidemiology of Incontinence in the County Of Nord-Trondelag (EPICONT) study showed an association between heavy smoking (20 cigarettes/day) and incontinence, probably due to frequent coughing, which increases intra-abdominal pressure, and also due to an interaction between smoking and estrogens, which negatively affects collagen synthesis [22]. Among comorbidities, diabetes seems to contribute to the development of PFDs because of an alteration to the microcirculation in the pelvic floor: 20% of women affected by type 2 diabetes mellitus have an increased risk of PFDs. Women who work as laborers and in factories and those who are homemakers have an increased risk of developing PFDs. Menopausal hormone therapy and the oral contraceptive pill also increase the risk of developing PFDs [2]. Finally, an excessive consumption of coffee and tea can increase the incidence of urinary incontinence [2].

2.4.4 Decompensating Factors

Psychiatric comorbidities, such as altered mental status and dementia, can cause functional pelvic floor decompensation [2].

2.5 Conclusions

PFDs remain an underestimated problem, probably because they manifest with embarrassing symptoms in an older and comorbid population. Although PFDs are diseases with a very low morbidity and no mortality, they have a strong negative impact on the quality of life, and they are characterized by high cost of treatment. Also, the incidence of PFDs is predicted to increase in the coming years.

References

1.

Subak LL, Waetjen LE, van den Eeden S (2001) Cost of pelvic organ prolapse surgery in the United States. Obstet Gynecol 98:646–651PubMedCrossRef

2.

Sung WS, Hampton BS (2009) Epidemiology of Pelvic Floor Dysfunction. Obstet Gynecol Clin N Am 36:421–443CrossRef

3.

Wu JM, Hundley AF, Fulton RG (2009) Forecasting the prevalenceof pelvic floor disorders in US women 2010 to 2050. Obstet Gynecol 114: 1278–1283PubMedCrossRef

4.

Shah AD, Kohli N, Rajan SS, Hoyte L (2008) The age distribution, rates and types of surgery for pelvic organ prolapse in the USA. Int. Urogynecol J Pelvic Floor Dysfuntion 19:89–96CrossRef

5.

Wu MJ, Ward RM, Allen-Brady KL et al (2012) Phenotyping clinical disorders:lessons learned from pelvic organ prolapse. Am J Obstet Gynecol 9378:2085–2086

6.

Kepenekci I, Keskinkilic B, Akinsu F et al (2011) Prevalence of pelvic floor disorders in the female population and the impact of Age, Mode of Delivery and Parity. Dis Col Rectum 54:85–94CrossRef

7.

Nygaard I, Barber MD, Burgio KL et al (2008) Prevalence of symptomatic pelvic floor disorders in US women. J Am Med Assoc 300:1311–1316CrossRef

8.

Thom DH, van den Eeden SK, Ragins AL et al (2006) Differences in prevalence of urinary incontinence by race/ethnicity. J Urol 175:259–264PubMedCrossRef

9.

Hendrix SL, Clark A, Nygaard I et al (2002) Pelvic organ prolapse in the women health’s initiative: gravity and gravidity. Am J Obstet Gynecol 186:1160–1166PubMedCrossRef

10.

Ribas Y, Saldana E, Marti-Raguè J et al (2011) Prevalence and Pathophysiology of functional constipation among women in Catalonia, Spain. Dis Colon Rectum 54:1560–1569PubMedCrossRef

11.

Moalli PA, Shand SH, Zyczynski HM et al (2005) Remodeling of vaginal connective tissue in patients with prolapse. Obstet Gynecol Clin N Am 106:953–963

12.

McGlone L, Patole S (2004) Neonatal genital prolapse. J Paediatr Child Health 40:156–157PubMedCrossRef

13.

Baragi RV, Delancey JO, Caspari R et al (2002) Difference in pelvic floor area between Africans, American and European America women. Am J Obstet Gynecol 187:111–115PubMedCrossRef

14.

Handa VL, Lockhart ME, Fielding JR et al (2008) Racial differences in pelvic anatomy by mangnetic resonance imaging. Obstet Gynecol 111:914–920PubMedCrossRef

15.

Howard D, Delancey JO, Tunn R et al (2000) Racial differences in the structure and function of the stress urinary continence mechanism. Obstet Gynecol 95:713–717PubMedCrossRef

16.

Dietz HP, Aust N Z J (2008) Prolapse worsens with age, doesn’t it? Obstet Gynaecol 48:587–591

17.

Savoye-Collet C, Savoye G, Kining E et al (2010) Gender influence of defecografic abnormalities in patient with posterior pelvic floor disorders. World J Gastroenterol 16:462–466PubMedCrossRef

18.

Lukacz ES, Laurence JM, Contreras R et al (2006) Parity, mode of delivery, and pelvic floor disorders. Obstet Gynecol 107: 1253–1260PubMedCrossRef

19.

Handa VL, Garrett E, Hendrix S et al (2004) Progression and remission of pelvic organ prolapse: a longitudinal study of menopausal women. Am J Obstet Gynecol 190:27–32PubMedCrossRef

20.

Sileri P, Franceschilli L, Cadeddu F et al (2012)Prevalence of defaecatory disorders in morbidly obese patients before and after bariatric surgery. J Gastrointest Surg 16:62–66PubMedCrossRef

21.

Sileri P, Iacoangeli F, Staar F et al (2012) Nervosa Anorexia Leads to Defecation Disorders Compared to General Population. Gastroenterology 142.5:S1072–S1073

22.

Hannestad YS, Rortveit G, Sandvik H et al (2000) A community based epidemiological survey of female urinary incontinence: the Norwegian EPICONT study. Epidemiology of Incontinence In the County Of Nord-Trondelag. J ClinEpidemiol 53:1150–1157CrossRef