Background
Obstructive defecation syndrome (ODS) is a poorly understood condition, characterized by the urge to defecate but an impaired ability to evacuate the rectum [
1,
2]. The symptoms include frequent visits to the toilet with unsuccessful evacuation attempts, prolonged straining, anorectal discomfort or pain, fresh rectal bleeding, a sensation of incomplete evacuation, and the need for manual assistance [
2,
3]. Structural abnormalities such as rectocele, enterocele or genital prolapse, and non-relaxing puborectalis may be associated with ODS, or coexist [
4]. However, the internal rectal mucosal prolapse and rectal intussusception have been recognized as major pathomorphological determinants of ODS, and consequently, a plethora of abdominal, vaginal, and laparoscopic surgical procedures have been used to correct the underlying condition [
5‐
8].
As a minimally invasive technique for achieving a full-thickness resection of the distal rectum, stapled transanal rectal resection (STARR) has been proposed for the treatment of ODS by performing two firings of the PPH-01 circular stapler (Ethicon Endo-Surgery, Inc., Cincinnati, OH), which was originally designed for use in stapled hemorrhoidopexy [
9,
10]. In 2006, the National Institute for Health and Care Excellence (NICE) in the United Kingdom issued clinical guidance on STARR concluding that the current evidence for its safety and efficacy for ODS did not appear adequate for this procedure to be used without special arrangements for consent and for audit or research [
4].
In response to the NICE guidance, the European STARR registry was established through the collaboration between the manufacturer, Ethicon Endo-Surgery (Europe) GmbH, Norderstedt, Germany, and the colorectal societies in France, Germany, Italy, and the UK. The real-world outcomes from this registry have recently been published, reinforcing the conclusions from single- and multicenter trials that STARR provides a significant patient benefit, at least in the short term, and can be performed safely and without major morbidity [
11‐
15]. Based on the published evidence, NICE issued its updated clinical guidance on STARR in 2010, concluding that: “The current evidence on the safety and efficacy of stapled transanal rectal resection (STARR) for obstructed defecation syndrome (ODS) is adequate for this condition which can significantly affect the quality of life. The procedure may therefore be used with normal arrangements for clinical governance, consent and audit” [
5].
Despite these conclusions on its proven safety and efficacy by the leading independent scientific institute (NICE), the limitations of STARR, mostly related to the design of the circular stapler used, were recognized by a broad surgical community. During this transanal procedure, the rectal wall resection is performed “blind” after the insertion of the circular stapler in the lower rectum, which might cause the entrapment of the device in the dilator and increase the risk of rectal perforation [
2,
16]. Furthermore, the volume of resection was dependent on the capacity of the circular stapler housing rather than on the size of the underlying rectal intussusceptions, without the possibility for surgeons to tailor the extent of the rectal resection to the size of the prolapse [
2,
17].
As a response to the observed difficulties, a new stapling device, the CONTOUR® TRANSTAR™ curved cutter-stapler (Ethicon Endo-Surgery, Inc., Cincinnati, OH), was designed to improve STARR by allowing the tailored circumferential correction of the internal rectal prolapse under continuous visual control. Following the stapler development, the innovative transanal stapling technique STARR with CONTOUR® TRANSTAR™, shortly named TRANSTAR, has been proposed for the treatment of ODS [
2,
16,
17] and was selectively launched in European countries where the health care decision-makers explicitly recommended the broad assessment of transanal stapling procedures in local clinical practice [
4,
5,
7].
A major challenge in assessing local practice reported in the literature previously, concluded that the variation phenomenon is so widespread and robust in local practice that it can be found almost anywhere where health care researchers look for it: between the care of the very young and the very old, between inpatient and outpatient settings, and between several geographic regions [
18]. The aim of this study was to assess the short-term safety and effectiveness of TRANSTAR in the real-world clinical environment where the variation phenomenon exists.
Discussion
In this multicenter study, 22 individual surgeons assessed the short-term safety, clinical effectiveness, and quality of life outcomes after TRANSTAR performed in the real-world clinical setting throughout Europe. The primary functional endpoint was the validated KESS constipation score, which improved statistically significantly on all individual score items between baseline and 12 months follow-up. Consequently, for the vast majority of patients defecation difficulties improved postoperatively, with 80 % changing from constipated patients to healthy individuals, according to the cut-off criterion from the score validation report [
20]. The risk assessment based on the changes in the validated KESS score showed a highly significant, more than ten times (OR = 10.6) reduction in the chance to experience symptoms of ODS at 12 months postoperatively, and the number of patients needed to treat for reaching this benefit was very low (NNT = 2). This reflects the real-world effectiveness of this transanal stapling procedure in the treatment of ODS. To our knowledge, this is the first study where the validated KESS score has been used as a primary functional endpoint to assess the clinical effectiveness of TRANSTAR.
Although not validated, the in the literature broadly reported Longo’s ODS score was the secondary functional endpoint in this cohort. It improved significantly, reflected by the decrease in its overall mean and median values (−10.12 and −11, respectively) at 12 months follow-up as compared to baseline. In the literature, Wolff et al. [
27] reported a significant improvement in the ODS score after TRANSTAR, expressed as a decrease (−11) in its median score value, at 6 months postoperatively. Savastano et al. [
28] recently reported a significant improvement in ODS score at 6 months follow-up, expressed as a decrease (−10.8) in its mean score value. Lenisa et al. [
16] reported an even larger improvement in ODS score at 1 year after TRANSTAR, expressed as a decrease in mean score (−14.6). In the current study, the observed mean and median ODS score improvements at 12 months follow-up appeared to be very similar to the significant ODS changes reported in recently published trials. This reinforces the clinical effectiveness of TRANSTAR as assessed by the KESS score in this study.
The impressive improvements observed in the functional constipation scores are supported by the significant improvement in constipation-specific quality of life as measured by the validated PAC-QoL score. The disease-specific PAC-QoL score improved statistically significantly on all four quality of life domains: patient’s satisfaction, physical discomfort, psychosocial discomfort, and worries and concerns, reaching statistical significance at 12 months follow-up as compared to baseline. The generic quality of life score EQ-5D improved numerically without reaching statistical significance, probably due to its relatively high baseline value (0.82) in this cohort.
In the literature, Jane et al. reported significant improvements in the validated quality of life instruments EQ-5D and PAC-QoL at 12 months follow-up after STARR for ODS [
15]. It has also been reported that patient quality of life significantly improved after TRANSTAR, particularly on the mental components of the FIQL and SF36 instruments [
27]. In a recent randomized controlled trial, Bocassanta et al. [
29] reported that the SF36 Health Survey score significantly improved after STARR and TRANSTAR, and that TRANSTAR patients showed a trend towards better satisfaction. The patient reported outcomes in this study reinforce evidence from previous series that transanal stapling procedures for ODS significantly improve constipation-related patient quality of life.
Fecal incontinence has preoperatively been seen as a typical symptom of ODS, especially in patients with grade III rectal intussusception and rectoceles [
30], having negative impact on patients’ quality of life. Moreover, fecal incontinence also negatively affects well-being in patients with other anorectal disorders [
31‐
34]. However, in recently published studies, it was observed that fecal incontinence usually improved after transanal stapling procedures for ODS. In the STARR Registry, Jane et al. [
16] reported a significant improvement in the validated Cleveland Clinic Fecal Incontinence score at 12-month follow-up as compared with baseline, and this was mirrored by a significant improvement in patient-reported symptoms of incontinence/soiling, captured as a component of the symptom severity score [
15]. Wolf et al. [
27] reported that all preoperatively incontinent patients included in their trial were continent at 6 months after TRANSTAR. Lenisa et al. [
16] reported a 41 % incontinence cure rate after TRANSTAR at 1-year follow-up as compared to baseline. Isbert et al. [
35] compared STARR and TRANSTAR at 1-year follow-up, reporting that neither technique compromised anal sphincter function, and that the postoperatively gained ability to effectively evacuate the rectum may rather help in reducing incontinence episodes. Additionally, it has been observed that patients in whom fecal incontinence occurred as a new symptom after TRANSTAR tended to be those with a preexisting asymptomatic incontinence, appearing after anatomic restoration [
27,
35].
In this cohort study, the risk assessment (OR = 0.30) showed a significant reduction in the chance to experience fecal incontinence at 12 months after TRANSTAR as compared to baseline. The real-world data from this study reinforces the published evidence, showing that fecal incontinence combined with an intact anal sphincter, observed preoperatively, may not be a contraindication for proposing transanal surgery for ODS in itself [
15,
16,
27,
35].
As a component of impaired continence, defecatory urgency has been seen as a common postoperative finding after surgery using transanal stapling. Urge symptoms were reported after a low anterior resection for rectal cancer and observed up to 12 months postoperatively, without requiring any additional therapy [
36]. In the treatment of ODS, defecatory urgency was often recorded after STARR and after TRANSTAR [
15,
16,
37]. In the majority of patients, the urge symptoms disappeared postoperatively without the need for any additional therapy, irrespective of whether it was observed as a new onset of the symptom or it already persisted as a symptom of the disease at baseline [
16,
27,
35]. However, in the European STARR registry, 26.8 % of patients still complained of urgency at 1-year follow-up [
15]. Renzi et al. [
17] and Savastano et al. [
28] reported an incidence of urge symptoms of 17.2 and 18.7 %, respectively, at 6 months after TRANSTAR. The reduction in the rectal ampula volume and modification of rectal sensitivity, as the natural consequences of the TRANSTAR technique, appear to be the reason for the increased risk of urge symptoms postoperatively [
16,
27,
35].
In this study, the risk assessment showed a nonsignificant increase (OR = 1.15) in the chance to experience defecatory urgency at 12 months follow-up as compared to baseline. Consequently, St. Mark’s incontinence score, which includes a specific urgency measure, was the only functional score in this study that improved nonsignificantly at 12 months follow-up, probably due to a negative impact of urgency on the overall score. However, patients should be informed about the risk of urge symptoms, possibly for a prolonged period of time after transanal stapling procedures for ODS.
In recent series, Wolf et al. [
27] and Martelucci et al. [
37] reported TRANSTAR-related morbidity rates of 8 and 16 %, respectively. Renzi et al. [
17] reported up to 31 % early complications and 24 % late complications after TRANSTAR.
The safety analysis in this study showed a lower percentage of intra- and postoperative complications recorded, contributing to the TRANSTAR-related morbidity rate of 11 %. Intraoperatively, a lower proportion of 3 % complications such as a partial dehiscence and spiraling of the staple line were recorded in this study, without any need for postoperative therapy. Lenisa et al. reported moderate intraoperative difficulties with TRANSTAR, including 5 % partial dehiscence and 4 % spiraling of the staple line, concluding that the spiral resection of the rectum during TRANSTAR may result from technical mistakes, such as inappropriate traction on the parachute stitches at the top of the internal rectal prolapse, or from a larger amount of the rectal wall incorporated into the jaw of the device [
16]. Accordingly, the immediate observation of the staple line to detect possible staple line leakages has been recommended [
16].
Postoperatively, 5 % postoperative bleeding, 2 % urinary retention, and 1 % persistent pain were recorded in this study. The majority of patients with postoperative bleeding experienced self-limiting bleeding episodes, and one patient needed an additional surgical intervention for the revision of a perirectal hematoma.
Postoperative bleeding has been presented in various series in the literature as occurring in 1.5 to 7 % of patients after TRANSTAR. Episodes are usually self-limiting, but if needed they can be managed successfully with conservative treatment or in rare cases by revision of the staple line [
16,
35,
38].
According to recent series, the incidence of acute urinary retention varies from 1.2 to 10.3 % and usually requires short-term urinary catheterization [
27,
37,
38], which is in accordance with the two patients with urinary retention after TRANSTAR in this study.
Moreover, it has been reported that some patients might suffer from persistent anorectal pain after transanal stapling procedures, caused by a proctitis due to retained staples [
39]. The removal of the retained staples led to resolution of the symptoms in previously published series [
16,
27]. Similarly, prolonged anorectal pain was observed postoperatively in one patient in this study, and the surgical removal of the retained staples contributed to its resolution.
However, abdominal pain can also be observed preoperatively, as part of the ODS symptoms [
2]. In this study, the risk assessment showed a significant reduction in the chance of experiencing abdominal pain (OR = 0.32) at 12 months follow-up as compared to baseline. The data from this study support previously published series concluding that retained staples might occasionally be a cause of persistent pain after TRANSTAR, but overall, the risk of postoperative abdominal pain as a symptom of ODS seemed to be significantly reduced.
No major or life-threatening complications after TRANSTAR were recorded in this study, although they have been reported in the literature. A rectal perforation was reported by Schulte et al. [
40], in which intraperitoneal occurring emphysema was treated conservatively. A large hematoma in the mesorectum extending towards both kidneys requiring a laparotomy was reported by Gelos et al. after TRANSTAR [
41]. Martelucci et al. [
37] reported a rectal perforation and a rectovaginal fistula after TRANSTAR, complications which were also reported for the original STARR technique [
37,
42]. Savastano et al. [
28] reported a hemoperitoneum after TRANSTAR, which was treated with synchronous colostomy and subsequent recanalization.
Finally, if compared with the safety data from previously published trials, the TRANSTAR-related morbidity profile observed in this study appears to be acceptable.
Data incompleteness could be seen as a limitation of this study because the questionnaires used for the 12-months analysis had a completeness range of 63–65 %, according to the scoring system used. The reason for this is thought to be that the majority of the study population consisted of elderly women, and some felt embarrassed answering detailed questions concerning their sexual functioning and defecation disorders. Accordingly, some patients provided answers only for specific chapters of the questionnaires, or they refused to fill out the questionnaires preoperatively, and only did so after surgery. However, this is not unexpected for an observational, real-world study. For example, in the STARR registry, it was reported that for the patients eligible for 12-month follow-up analysis, the completeness of data collection varied from 41 to 64 % according to the scoring system used [
16]. Isbert et al. [
35] reported in their comparative observational trial that 58 % of patients in the STARR group and 46 % of patients in the TRANSTAR group attended their follow-up assessments at 12 months.
Furthermore, it can be argued that the relatively short follow-up of only 12 months postoperatively presents a limitation of this study and that it needs to be proven that the current functional results are sustainable in the longer term. Indeed, outcomes from randomized clinical trials from 2 and 3 years after TRANSTAR have recently been published. Renzi et al. [
43] reported a longer maintenance of symptom relief in patients who had undergone TRANSTAR compared to those who underwent STARR at 2-year follow-up. Bocassanta et al. [
29] were able to demonstrate a significantly lower incidence of fecal urgency and internal prolapse recurrence as two major benefits of TRANSTAR when compared to STARR at 3-year follow-up. The authors concluded that the prolapse recurrence rate was significantly lower in favor of TRANSTAR compared to STARR, probably due to the larger extent of rectal wall resection [
29]. It can be concluded that the impressive functional results achieved in the relatively artificial environment of these randomized clinical trials need to be confirmed in broader surgical practice with larger patient populations.