Differences in ano-neorectal physiology of ileoanal and coloanal reconstructions for restorative proctectomy

[Low anterior resection syndrome-Causes and treatment approaches]

BACKGROUND

With improvement of the oncological prognosis and more sphincter-preserving procedures for rectal cancer of the lower third, the functional sequelae of anterior rectal resection become more and more predominant and are summarized under the term low anterior resection syndrome (LARS).

MATERIAL AND METHODS

In this narrative review the causes, associated factors, prevalence, diagnostics and treatment strategies are presented based on an evaluation of the international literature.

RESULTS

The central role of the rectum in the physiology of defecation and continence explains the frequency of symptoms following anterior rectal resection. In an unselected patient population a major LARS is to be expected in approximately 40% and a minor LARS in approximately 20%. The most important factor is the length of the remaining rectal stump. The diagnosis of LARS is made clinically and can be quantified by scores, especially by the LARS score. Treatment options range from patient counselling to stoma construction and a symptom-related, stepwise approach is generally accepted.

CONCLUSION

While the evidence for the causes, the quantification and determination of associated factors of LARS is good, the treatment options are based either on experience or on only few studies.

Abnormal Neuronal Response to Rectal and Anal Stimuli in Patients Treated for Distal Rectal Cancer With High-Dose Chemoradiotherapy Followed By Watchful Waiting

BACKGROUND

Watchful waiting in patients with rectal cancer with complete clinical response after chemoradiation therapy has gained increased popularity to avoid morbidity and mortality associated with surgery. Irradiation of the pelvis causes bowel dysfunction, but the effect on anorectal sensory function remains obscure in this patient category.

OBJECTIVE

The aim of this study was to characterize the sensory pathways of the gut-brain axis in patients with rectal cancer treated solely with chemoradiation therapy (nonconventional regime/dose) compared with healthy volunteers.

DESIGN

This is an explorative study.

SETTINGS

Sensory evaluation by rectal distension was performed and cortical evoked potentials were recorded during rapid balloon distensions of the rectum and anal canal. Latencies and amplitudes of cortical evoked potentials were compared, and the relative amplitude of 5 spectral bands from recorded cortical evoked potentials was used as an additional proxy of neuronal processing.

PATIENTS

Patients with rectal cancer solely with chemoradiation therapy (n = 13) a median of 3.2 years ago (range, 2.3-5.6 y) and healthy volunteers (n = 13) were included.

MAIN OUTCOME MEASURES

Cortical evoked potentials were measured.

RESULTS

Patients had 35% lower rectal capacity at a maximum tolerable volume (p = 0.007). We found no differences in rectal cortical evoked potential latencies (p = 0.09) and amplitudes (p = 0.38) between groups. However, spectral analysis of rectal cortical evoked potentials showed a decrease in θ (4-8 Hz) and an increase in β (12-32 Hz) band activity in patients (all p < 0.001). Anal cortical potentials showed an increase in α (8-12 Hz) and β and a decrease in γ (32-70 Hz) band activity (all p < 0.001) in patients compared with healthy volunteers.

LIMITATIONS

This is an explorative study of limited size.

CONCLUSIONS

Chemoradiation therapy for distal rectal cancer causes abnormal cortical processing of both anal and rectal sensory input. Such central changes may play a role in symptomatic patients, especially when refractory to local treatments. See Video Abstract at http://links.lww.com/DCR/B270. RESPUESTA NEURONAL ANORMAL A ESTÍMULOS RECTALES Y ANALES, EN PACIENTES TRATADOS POR CÁNCER RECTAL DISTAL, CON QUIMIORRADIOTERAPIA DE DOSIS ALTA, SEGUIDA DE ESPERA VIGILANTE: La espera vigilante en pacientes de cáncer rectal, con respuesta clínica completa después de la quimiorradiación, ha ganado una mayor popularidad en evitar la morbilidad y mortalidad asociadas con la cirugía. La irradiación de la pelvis causa disfunción intestinal, pero el efecto sobre la función sensorial ano-rectal sigue siendo no claro, en esta categoría de pacientes.El objetivo de este estudio, fue caracterizar las vías sensoriales del eje intestino-cerebro en pacientes con cáncer rectal, tratados únicamente con quimiorradiación (régimen / dosis no convencional), en comparación con voluntarios sanos.Es un estudio exploratorio.Se realizó una evaluación sensorial por distensión rectal y se registraron los potenciales evocados corticales, durante las distensiones rápidas con balón en recto y canal anal. Se compararon las latencias y amplitudes de los potenciales evocados corticales, y la amplitud relativa de cinco bandas espectrales registradas, de potenciales evocados corticales, se usaron como proxy adicional del procesamiento neuronal.Pacientes de cáncer rectal, únicamente con terapia de quimiorradiación (n = 13) mediana de 3.2 años (rango 2.3-5.6) y voluntarios sanos (n = 13).Potenciales evocados corticales.Pacientes tuvieron una capacidad rectal menor del 35%, al volumen máximo tolerable (p = 0.007). No encontramos diferencias en las latencias potenciales evocadas corticales rectales (p = 0.09) y amplitudes (p = 0.38) entre los grupos. Sin embargo, el análisis espectral de los potenciales evocados corticales rectales, mostró una disminución en theta (4-8 Hz) aumento en beta (12-32 Hz), y actividad en banda en pacientes (todos p <0.001). Los potenciales evocados corticales anales mostraron un aumento en alfa (8-12 Hz) y beta, disminución en gamma (32-70 Hz), y actividad en banda (todos p <0.001), en pacientes comparados a voluntarios sanos.Este es un estudio exploratorio de tamaño limitado.La quimiorradiación para el cáncer rectal distal, ocasiona procesos corticales sensoriales anormales anales y rectales. Tales cambios centrales pueden desempeñar un papel en pacientes sintomáticos, especialmente cuando son refractarios a tratamientos locales. Consulte Video Resumen en http://links.lww.com/DCR/B270.

Abnormal gut motility in inflammatory bowel disease: an update

BACKGROUND

There is substantial evidence linking disturbed gastrointestinal motility to inflammation. Thus, it is not surprising that abnormalities of gastrointestinal motility play a role in inflammatory bowel disease (IBD), affecting patient outcomes. We performed a review of the literature to investigate the relationship between abnormal gut motility and IBD.

METHODS

With an extensive literature search, we retrieved the pertinent articles linking disturbed gut motility to IBD in various anatomical districts.

RESULTS

The evidence in the literature suggests that abnormal gastrointestinal motility plays a role in the clinical setting of IBD and may confuse the clinical picture.

CONCLUSIONS

Abnormal gut motility may be important in the clinical setting of IBD. However, additional data obtained with modern techniques (e.g., magnetic resonance imaging) are needed to individuate in a more precise manner gastrointestinal motor dysfunctions, to understand the nature of clinical manifestations and properly tailor the treatment of patients.

Anorectal Function After Ileo-Rectal Anastomosis Is Better than Pelvic Pouch in Selected Ulcerative Colitis Patients

BACKGROUND

With a lifelong perspective, 12% of ulcerative colitis patients will need a colectomy. Further reconstruction via ileo-rectal anastomosis or pouch can be affected by patients' perspective of their quality of life after surgery.

AIM

To assess the function and quality of life after restorative procedures with either ileo-rectal anastomosis or ileal pouch-anal anastomosis in relation to the inflammatory activity on endoscopy and in biopsies.

METHOD

A total of 143 UC patients operated with subtotal colectomy and ileo-rectal anastomosis or pouches between 1992 and 2006 at Linköping University Hospital were invited to participate. Those who completed the validated questionnaires (Öresland score, SF-36, Short Health Scale) were offered an endoscopic evaluation including multiple biopsies. Associations between anorectal function and quality of life with type of restorative procedure and severity of endoscopic and histopathologic grading of inflammation were evaluated.

RESULTS

Some 77 (53.9%) eligible patients completed questionnaires, of these 68 (88.3%) underwent endoscopic evaluation after a median follow-up of 12.5 (range 3.5-19.4) years after restorative procedure. Patients with ileo-rectal anastomosis reported better overall Öresland score: median = 3 (IQR 2-5) for ileo-rectal anastomosis (n = 38) and 10 (IQR 5-15) for pouch patients (n = 39) (p < 0.001). Anorectal function (Öresland score) and endoscopic findings (Baron-Ginsberg score) were positively correlated in pouch patients (tau: 0.28, p = 0.006).

CONCLUSION

Patients operated with ileo-rectal anastomosis reported better continence compared to pouches. Minor differences were noted regarding the quality of life. Ileo-rectal anastomosis is a valid option for properly selected ulcerative colitis patients if strict postoperative endoscopic surveillance is carried out.

MRI defecography of the ileal pouch-anal anastomosis-contributes little to the understanding of functional outcome

PURPOSE

Variability in functional outcome after ileal pouch-anal anastomosis (IPAA) is to a large extent unexplained. The aim of this study was to use MRI to evaluate the morphology, emptying pattern and other pathology that may explain differences in functional outcome between well-functioning and poorly functioning pouch patients. A secondary aim was to establish a reference of normal MRI findings in pelvic pouch patients.

METHODS

From a previous study, the best and worst functioning patients undergoing IPAA surgery between 2000 and 2013 had been identified and examined with manovolumetric tests (N = 47). The patients were invited to do a pelvic MRI investigating pouch morphology and emptying patterns, followed by a pouch endoscopy.

RESULTS

Forty-three patients underwent MRI examination. We found no significant morphological or dynamic differences between the well-functioning and poorly functioning pouch patients. There was no correlation between urge volume and the volume of the bony pelvis, and no correlation between emptying difficulties or leakage and dynamic MRI findings. Morphological MRI signs of inflammation were present in the majority of patients and were not correlated to histological signs of inflammation. Of the radiological signs of inflammation, only pouch wall thickness correlated to endoscopic pouchitis disease activity index scores.

CONCLUSION

It seems MRI does not increase the understanding of factors contributing to functional outcome after ileal pouch-anal anastomosis. Unless there is a clinical suspicion of perianal/peripouch disease or pelvic sepsis, MRI does not add value as a diagnostic tool for pelvic pouch patients. Endoscopy remains the golden standard for diagnosing pouch inflammation.

Determinants of optimal bowel function in ileal pouch-anal anastomosis - physiological differences contributing to pouch function

BACKGROUND

Variability in functional outcome after ileal-pouch anal anastomosis (IPAA) is to a large extent unexplained. The aim of this study was to perform multiple physiological and biochemical tests including an endoscopic examination with histology on IPAA patients with well and poorly functioning pouches to determine factors, or combinations thereof, contributing to functional outcome.

METHODS

All patients with ulcerative colitis undergoing restorative proctocolectomy between 2000 and 2013 (N = 108) were interviewed using a pouch functioning score. The best and worst functioning quartiles were invited to undergo examination with a barostat measuring pouch volume at preset variable distension pressures, and a pouch endoscopy.

RESULTS

Forty five of 58 eligible patients agreed to participate. The most significant physiological parameter differing between the well and poorly functioning pouches was pouch volume at first sensation, urge and discomfort (p value <.001). Urge volumes were 213 (CI 171-256) ml for poorly and 352 (CI 305-401) ml for well functioning pouches. Pouchitis episodes were negatively correlated to function. The poorly functioning patients had a higher prevalence of histological signs of inflammation and hand-sewn anastomosis, and a longer remaining rectal cuff, however, nonsignificant. The pouch pressure at sensation thresholds did not differ between the groups.

CONCLUSIONS

Pouch volume is the most dominant predictor of pouch function in this study. The present comprehensive study of a multitude of different factors that possibly could be contributing to functional outcome, failed to shed much further light on the functional variability among pouch patients. The pouch physiology remains to a large extent unexplained.

[Hybrid TAMIS total mesorectal excision. A new perspective in treatment of distal rectal cancer - Technique and results]

BACKGROUND

Transanal minimally invasive surgery (TAMIS) represents a promising technique for total mesorectal excision (TME) with respect to radicalness and preservation of function. There are only few publications in the literature describing results in patients with distal rectal cancer.

METHODS

Between May 2013 and March 2015, 24 selected patients with a rectal carcinoma < 6 cm from the anal verge underwent a laparoscopically assisted TAMIS TME (Hybrid-TAMIS TME) procedure. This prospective observational study was conducted to examine the safety of the technique and the quality of TME surgery in distal rectal cancer and to assess the short-term postoperative outcome.

RESULTS

The median age of patients (18 male and 6 female) at the time of surgery was 57 years (range 35-77 years) and 7 patients (29 %) had a body mass index (BMI) > 30 kg/m(2). Specimen excision was carried out transanally in 19 patients. Pathological grading of TME specimens was good in 22 (92 %) and moderate in 2 cases. After neoadjuvant radiochemotherapy a complete pathological remission was identified in five patients. The median distal resection margin was 7 mm (range 2-30 mm), the median circumferential resection margin was 6 mm (range <1 mm-30 mm) and in 2 patients the tumor was ≤ 1 mm from the positive circumferential margin. A colonic reservoir was created in 19 patients (79 %) and no 30-day mortalities occurred. Morbidity was 29 %, including 1 anastomotic leak, 2 hematomas and 1 neurogenic bladder.

CONCLUSION

Hybrid-TAMIS TME for distal rectal cancer is safe and can provide a sphincter-preserving high-quality TME in difficult cases. Studies with long-term follow-up assessing oncological and functional results are mandatory.

Does Sacral Nerve Stimulation Improve Continence Through Enhanced Sensitivity of the Anal Canal? A Pilot Study

BACKGROUND

It has been suggested that the effects of sacral nerve stimulation against fecal incontinence involve neuromodulation at spinal or supraspinal levels.

OBJECTIVE

This study aims to investigate the afferent sensory pathways from the anorectum before and during sacral nerve stimulation.

DESIGN

This is an explorative study.

PATIENTS

Fifteen women with idiopathic fecal incontinence (mean age, 58 ± 12.2 years) were selected.

INTERVENTIONS

Cortical evoked potentials were recorded during repeated rapid balloon distension of the rectum and the anal canal both before and during temporary sacral nerve stimulation. Stimuli applied were individualized according to the subjective urge to defecate.

MAIN OUTCOME MEASURES

The main outcomes measured were 1) stimulus intensity, 2) latencies and amplitudes of cortical evoked potentials, and 3) spectral content in predefined frequency bands of cortical evoked potentials.

RESULTS

The median Wexner fecal incontinence score improved from 15.5 ± 3.6 before to 6.7 ± 5 during sacral nerve stimulation (p < 0.001). Sacral nerve stimulation did not affect the threshold for urge to defecate during rectal distension (p = 0.64) but reduced the threshold from stimulation of the anal canal by 50% (p = 0.03). No statistically significant differences were found in latencies, amplitudes, or spectral analysis.

LIMITATIONS

This is a pilot study of limited size.

CONCLUSIONS

In patients with idiopathic fecal incontinence, sacral nerve stimulation reduced the threshold for urge to defecate elicited from the anal canal, whereas supraspinal responses remained unaltered. This may suggest that sacral nerve stimulation, at least in part, acts via somatic afferent fibers enhancing anal sensation.

Diagnosis and treatment of faecal incontinence: Consensus statement of the Italian Society of Colorectal Surgery and the Italian Association of Hospital Gastroenterologists

Faecal incontinence is a common and disturbing condition, which leads to impaired quality of life and huge social and economic costs. Although recent studies have identified novel diagnostic modalities and therapeutic options, the best diagnostic and therapeutic approach is not yet completely known and shared among experts in this field. The Italian Society of Colorectal Surgery and the Italian Association of Hospital Gastroenterologists selected a pool of experts to constitute a joint committee on the basis of their experience in treating pelvic floor disorders. The aim was to develop a position paper on the diagnostic and therapeutic aspects of faecal incontinence, to provide practical recommendations for a cost-effective diagnostic work-up and a tailored treatment strategy. The recommendations were defined and graded on the basis of levels of evidence in accordance with the criteria of the Oxford Centre for Evidence-Based Medicine, and were based on currently published scientific evidence. Each statement was drafted through constant communication and evaluation conducted both online and during face-to-face working meetings. A brief recommendation at the end of each paragraph allows clinicians to find concise responses to each diagnostic and therapeutic issue.

Total proctocolectomy for rectal cancer in Lynch syndrome: indications and considerations

SUMMARY 

Patients with Lynch syndrome and rectal cancer present a unique clinical challenge. Management of the primary rectal cancer and prophylactic removal of the colon should be considered. In patients requiring a mesorectal excision, a combined prophylactic colon removal can be considered. Although surveillance of the colon with frequent colonoscopies is an alternative, concerns of metachronous colon cancer development support prophylactic removal of the colon as an alternative. Since data are not available to confirm superiority of either approach, the final decision is greatly dependent upon a patient's wishes and preferences. Patients interested in pursuing simultaneous prophylactic colon removal can be offered total proctocolectomy with either ileal pouch anal-anastomosis as a sphincter-preserving alternative or a total proctocolectomy with end ileostomy.

Topography of the extrinsic internal anal sphincter nerve supply during laparoscopic-assisted TAMIS TME: five key zones of risk from the surgeons' view

PURPOSE

Sparing the extrinsic autonomic innervation of the internal anal sphincter during total mesorectal excision is important for the preservation of anal sphincter function. This study electrophysiologically confirmed the topography of the internal anal sphincter nerve supply during laparoscopic-assisted transanal minimally invasive surgery for total mesorectal excision.

METHODS

This prospective study was conducted at two large multispecialty referral centers. Six patients (five males and one female) aged between 45 and 65 years with low rectal cancer (≤5 cm from the anal verge) were enrolled. Surgery was performed under electric stimulation of the pelvic autonomic nerves with observation of the electromyographic signals of the internal anal sphincter.

RESULTS

The minimally invasive transanal surgical approach enabled advantageous visualization of the pelvic autonomic nerves in all patients. In particular, extrinsic innervation to the internal anal sphincter near the levator muscle was consciously spared under electrophysiological confirmation. The evoked absolute electromyographic amplitudes of the internal anal sphincter during transanal minimally invasive surgery were significantly lower than the initial results of the laparoscopic approach [3.7 μV (interquartile range 2.4; 5.7) vs. 4.3 μV (interquartile range 3.1; 8.6); p = 0.002]. Five key zones of risk for pelvic autonomic nerve damage were identified. No complications occurred.

CONCLUSIONS

The electromyographic results of this preliminary study indicate advantages for sparing the internal anal sphincter innervation during transanal minimally invasive mesorectal dissection considering the specific in situ neuroanatomical topography.

Gastrointestinal motility disorders in inflammatory bowel diseases

The relationship between motility and inflammatory gastrointestinal disorders is at the same time complex and intriguing since these conditions might share some genetic, environmental, immunological and microbial predisposing factors. In addition, significant symptom overlapping may occur, muddling the waters within the clinical context. Although on one hand this represents a challenge for the clinician for a potential under- or over-treatment and diagnostic delay, on the other hand it possibly represents an opportunity for the researcher to better disclose the intimate relationship between chronic (often low-grade) inflammation, motor disorders and deranged sensory function. The best example is probably represented by Crohn’s disease and ulcerative colitis. In fact, a number of gastrointestinal motor disorders have been described in association with these diseases, disorders which span from the esophagus to the anorectum, and which will be extensively covered in this review. It is conceivable that at least part of this derangement is strictly related to inflammatory cytokine trafficking and neuromuscular changes; however, given the high prevalence of functional gastrointestinal disorders in the general population, this overlap might also be serendipitous. However, it is worth noting that literature data on this topic are relatively scarce, sometimes quite outdated, and mostly focused on the interplay between irritable bowel syndrome and inflammatory bowel disease. Nevertheless, both researchers and clinicians must be aware that symptoms related to gastrointestinal motility disorders may be highly prevalent in both active and inactive inflammatory bowel disease, correlate with greater psychological comorbidity and poorer quality of life, and may negatively influence the therapeutic approaches.

Treatment options to improve anorectal function following rectal resection: a systematic review

AIM

Common problems after rectal resection are loose stools, faecal incontinence, increased frequency and evacuation difficulties, for which there are various therapeutic options. A systematic review was conducted to assess the outcome of treatment options aimed to improve anorectal function after rectal surgery.

METHOD

Publications including a therapeutic approach to improve anorectal function after rectal surgery were searched using the following databases: MEDLINE, PubMed, EMBASE, Pedro, CINAHL, Web of Science, PsychInfo and the Cochrane Library. The focus was on outcome parameters of symptomatic improvement of faecal incontinence, evaluation of defaecation and quality of life.

RESULTS

The degree of agreement on eligibility and methodological quality between reviewers calculated with kappa was 0.85. Fifteen studies were included. Treatment options included pelvic floor re-education (n=7), colonic irrigation (n=2) and sacral nerve stimulation (SNS) (n=6). Nine studies reported reduced incontinence scores and a decreased number of incontinent episodes. In 10 studies an improvement in resting and squeeze pressure was observed after treatment with pelvic floor re-education or SNS. Three studies reported improved quality of life after pelvic floor re-education. Significant improvement of the Fecal Incontinence Quality of Life Scale was found in three studies after SNS.

CONCLUSION

Conservative therapies such as pelvic floor re-education and colonic irrigation can improve anorectal function. SNS might be an effective solution in selected patients. However, methodologically qualitative studies are limited and randomized controlled trials are needed to draw evidence-based conclusions.

Selective pelvic autonomic nerve stimulation with simultaneous intraoperative monitoring of internal anal sphincter and bladder innervation

BACKGROUND

Pelvic autonomic nerve preservation avoids postoperative functional disturbances. The aim of this feasibility study was to develop a neuromonitoring system with simultaneous intraoperative verification of internal anal sphincter (IAS) activity and intravesical pressure.

METHODS

14 pigs underwent low anterior rectal resection. During intermittent bipolar electric stimulation of the inferior hypogastric plexus (IHP) and the pelvic splanchnic nerves (PSN), electromyographic signals of the IAS and manometry of the urinary bladder were observed simultaneously.

RESULTS

Stimulation of IHP and PSN as well as simultaneous intraoperative monitoring could be realized with an adapted neuromonitoring device. Neurostimulation resulted in either bladder or IAS activation or concerted activation of both. Intravesical pressure increase as well as amplitude increase of the IAS neuromonitoring signal did not differ significantly between stimulation of IHP and PSN [6.0 cm H(2)O (interquartile range [IQR] 3.5-9.0) vs. 6.0 cm H(2)O (IQR 3.0-10.0) and 12.1 μV (IQR 3.0-36.7) vs. 40.1 μV (IQR 9.0-64.3)] (p > 0.05).

CONCLUSIONS

Pelvic autonomic nerve stimulation with simultaneous intraoperative monitoring of IAS and bladder innervation is feasible. The method may enable neuromonitoring with increasing selectivity for pelvic autonomic nerve preservation.

Intraoperative pelvic nerve stimulation performed under continuous electromyography of the internal anal sphincter

PURPOSE

The aim of this animal study was to investigate the effect of intraoperative pelvic nerve stimulation on internal anal sphincter electromyographic signals in order to evaluate its possible use for neuromonitoring during nerve-sparing pelvic surgery.

METHODS

Eight pigs underwent low anterior rectal resection. The intersphincteric space was exposed, and the internal (IAS) and external anal sphincter (EAS) were identified. Electromyography of both sphincters was performed with bipolar needle electrodes. Intermittent bipolar electric stimulation of the inferior hypogastric plexus and the pelvic splanchnic nerves was carried out bilaterally. The recorded signals were analyzed in its frequency spectrum.

RESULTS

In all animals, electromyographic recordings of IAS and EAS were successful. Intraoperative nerve stimulation resulted in a sudden amplitude increase in the time-based electromyographic signals of IAS (1.0 (0.5-9.0) μV vs. 4.0 (1.0-113.0) μV) and EAS (p < 0.001). The frequency spectrum of IAS in the resting state ranged from 0.15 to 5 Hz with highest activity in median at 0.77 Hz (46 cycles/min). Pelvic nerve stimulation resulted in an extended spectrum ranging from 0.15 to 20 Hz. EAS signals showed higher frequencies mainly in a range of 50 to 350 Hz. However, after muscle relaxation with pancuronium bromide, only the low frequency spectrum of the IAS signals was still present.

CONCLUSIONS

Intraoperative verification of IAS function by stimulation of pelvic autonomic nerves is possible. The IAS electromyographic response could be used to monitor pelvic autonomic nerve preservation.