Clinical, Biomechanical and Morphological Peculiarities of the Rectum in Patients with Obstructed Defecation Syndrome. Summary of the Doctoral Thesis

Abstract

Obstructed defecation syndrome (ODS) is a difficulty or inadequate rectal emptying for the last 3 months with symptom onset and at least 6 months prior to diagnosis, resulting in the need for straining at defecation and chronic constipation (Podzemny, Pescatori and Pescatori, 2015). Obstructed defecation syndrome (ODS) often manifests with chronic constipation (CC), which affects about 17 % of the general population revealing significantly higher levels in the elderly, especially people above the age of 70 – 20.6 % men and 25 % women (Choung et al., 2007). Approximately half of the patients with CC suffer from ODS (Rao, 2001). Constipation is a very common problem in general population. The estimates of the prevalence of constipation in North America ranged from 12 % to 19 %. Prevalence estimates by gender support a female-to-male ratio of 2.2:1 (Higgins and Johanson, 2004). 2.5 million physician visits for constipation have also been reported every year in the United States, leading to high financial costs (Sandler, Jordan and Shelton, 1990). The average cost of diagnosing an outpatient patient with constipation in the United States is approximately 2752$ (Rantis et al., 1997), but in hospital even more (Martin, Barghout and Cerulli, 2006). CC diagnosis and treatment have been previously shown to carry a high burden in terms of financial costs, and also on work performance and impact on the individual’s quality of life. A Canadian survey of a weighted sample of 1000 adults was conducted to determine the prevalence of gastrointestinal symptoms over the previous three months. 13.2 % of respondents missed work or school and 28.8 % were less productive, but nearly 10 % reported missing work or having been forced to leave work (Hunt et al., 2007). Psychological distress is linked to having persistent gastrointestinal symptoms and physiology of CC. Prolonged emotional stress can be considered a cause of CC and CC itself could be triggered and exacerbated by stress. It has been proven in studies that patients with functional bowel disorders have a higher risk of psychological disorders than the control group, and 40–50 % of such patients have confirmed psychiatric diagnoses (Koloski, Talley and Boyce, 2003). Constipation is frequently multifactorial. Constipation can be classified in three broad categories: normal-transit constipation, slow-transit constipation and disorders of defecatory or rectal evacuation (Lembo and Camilleri, 2003). Defecatory disorders can be a result of functional or anatomical pelvic floor alterations. Functional causes are mostly treated by conservative management, with surgery having a minor role only. In contrast, disorders with an underlying anatomical cause leading to ODS should be more considered for surgery (Riss and Stift, 2015). Two most frequent lesions of ODS are rectocele and rectoanal intussusception For treatment of ODS, both conservative and surgical approaches are used. Conservative management needs to be offered to all patients initially: fiber diet, plenty of water and bulking laxatives, biofeedback, rehabilitation and electrostimulation. Conservative treatment is ineffective only in 20 % of patients who subsequently can be considered for surgery (Podzemny, Pescatori and Pescatori, 2015). A great variety of operative techniques to treat patients with ODS exists there. There is no ideal technique and not every operation fits every patient and vice versa. According to a surgeon’s preference, the approach can be transabdominal (open or laparoscopic), transanal, transvaginal or transperineal. Additionally, resection or reconstructive surgery with or without mesh implantation could be also performed during each approach (Riss and Stift, 2015). All techniques have their advantages and disadvantages; thus, satisfying functional outcomes can only be achieved by offering a tailored approach to each individual patient. Each technique has also its risks and benefits; thus, careful patient selection is crucial to achieve optimal functional results (Janssen and van Dijke, 1994; Murthy et al., 1996). Morphological cause and pathological physiological mechanism of the development of ODS, as well as biomechanical justification of surgical treatment methods are still unclear. There are international studies about biomechanical properties of female minor pelvic organs (bladder, vagina and rectum); however, these studies were performed for women without rectal pathology (Rubod et al., 2012). There is another study assessing biomechanical properties of the rectal wall in vivo with impedance planimetry, but only total biomechanical properties of the rectal and pelvic muscles and ligaments were analysed, not assessing the rectal wall biomechanical properties separately (Dall et al., 1993). Rectocele is one of the main clinical findings of ODS that is a bulging of the front wall of the rectum into the back wall of the vagina. A rectocele could be detected also in clinically healthy female patients (Shorvon et al., 1989). Up to 93% of women are found to have a small rectocele less than 2.5 cm (Palit et al., 2014). The study suggests that rectocele may be the result of ODS, but clear relationships should be still determined (Hicks et al., 2013). There are limited data on biomechanical analysis of the ODS surgical specimens, as well as pathophysiological explanation and justification of the surgery. In general, understanding of the pathophysiological mechanism of rectocele’s formation is still relatively weak.