Rating of camera navigation skills in colorectal surgery.

PURPOSE: In advanced minimally invasive surgery the laparoscopic camera navigation (LCN) quality can influence the flow of the operation. This study aimed to investigate the applicability of a scoring system for LCN (SALAS score) in colorectal surgery and whether an adequate scoring can be achieved using a specified sequence of the operation. METHODS: The score was assessed by four blinded raters using synchronized video and voice recordings of 20 randomly selected laparoscopic colorectal surgeries (group A: assessment of the entire operation; group B: assessment of the 2nd and 3rd quartile). Experience in LCN was defined as at least 100 assistances in complex laparoscopic procedures. RESULTS: The surgical teams consisted of three residents, three fellows, and two attendings forming 15 different teams. The ratio between experienced and inexperienced camera assistants was balanced (n = 11 vs. n = 9). Regarding the total SALAS score, the four raters discriminated between experienced and inexperienced camera assistants, regardless of their group assignment (group A, p < 0.05; group B, p < 0.05). The score's interrater variability and reliability were proven with an intraclass correlation coefficient of 0.88. No statistically relevant correlation was achieved between operation time and SALAS score. CONCLUSION: This study presents the first intraoperative, objective, and structured assessment of LCN in colorectal surgery. We could demonstrate that the SALAS score is a reliable tool for the assessment of LCN even when only the middle part (50%) of the procedure is analyzed. Construct validity was proven by discriminating between experienced and inexperienced camera assistants.

Robot-assisted minimally invasive esophagectomy (RAMIE) compared to conventional minimally invasive esophagectomy (MIE) for esophageal cancer: a propensity-matched analysis.

Robot-assisted minimally invasive esophagectomy (RAMIE) is increasingly being applied as treatment for esophageal cancer. In this study, the results of 50 RAMIE procedures were compared with 50 conventional minimally invasive esophagectomy (MIE) operations, which had been the standard treatment for esophageal cancer prior to the robotic era. Between April 2016 and March 2018, data of 100 consecutive patients with esophageal carcinoma undergoing modified Ivor Lewis esophagectomy were prospectively collected. All operations were performed by the same surgeon using an identical intrathoracic anastomotic reconstruction technique with the same perioperative management and pain control regimen. Intra-operative and postoperative complications were graded according to definitions stated by the Esophagectomy Complications Consensus Group. Data analysis was carried out with and without propensity score matching. Baseline characteristics did not show significant differences between the RAMIE and MIE group. Propensity score matching of the initial group of 100 patients resulted in two equal groups of 40 patients for each surgical approach. In the RAMIE group, the median total lymph node yield was 27 (range 13-84) compared to 23 in the MIE group (range 11-48), P = 0.053. Median intensive care unit (ICU) stay was 1 day (range 1-43) in the RAMIE group compared to 2 days (range 1-17) in the MIE group (P = 0.029). The incidence of postoperative complications was not significantly different between the two groups (P = 0.581). In this propensity-matched study comparing RAMIE to MIE, ICU stay was significantly shorter in the RAMIE group. There was a trend in improved lymphadenectomy in RAMIE.

"Prophylactic" transanal irrigation (TAI) to prevent symptoms of low anterior resection syndrome (LARS) after rectal resection: results at 12-month follow-up of a controlled randomized multicenter trial.

BACKGROUND: Low anterior resection syndrome (LARS) is associated with a severe negative impact on patients' quality of life (QOL). In a recent prospective randomized controlled trial (RCT) by our group, early ("prophylactic") use of transanal irrigation (TAI) following rectal resection for rectal cancer was shown to improve symptoms associated with LARS significantly compared with a group under supportive therapy (ST) within 1 and 3 months following closure of the protective ileostomy. The aim of the present study was to evaluate the outcome after 12 months when patients had the option to choose between the two therapeutic options and/or modify the regimen of TAI (volume and time). METHODS: In the RCT, 18 patients had been allocated to start with TAI following ileostomy closure, while 19 patients remained on ST only. Once the 3-month follow-up had been completed patients could choose between TAI or ST, respectively, and were invited for follow-up after 12 months. The maximum number of bowel movements during the day and the Wexner and LARS score as well as physical (PC) and mental (MC) component of the SF-36 questionnaire were evaluated. Furthermore, in patients who had changed their treatment arm, reasons for this decision were reported. RESULTS: Six patients were lost to follow-up (all in the ST group). One patient from the ST group started with TAI due to problems associated with LARS, bringing the total number of TAI patients to 19. Nine patients from the previous TAI arm changed to ST due to the long duration of the emptying process (n: 8) or pain during TAI (n: 1), respectively. After 12 months, the median volume of water used for irrigation was 600 ml (range 200-1000 ml). The ten patients who continued with TAI patients showed a lower number of defecation episodes per daytime (TAI median 3; 1-6, ST median 5; 2-10, p: 0.018) and per night (TAI median 0; 0-1, ST median 1; 0-5, p: 0.004) compared to the ST group. Although the LARS score was lower in patients who used TAI after 12 months (TAI median 18; 9-32, ST median 30; 3-39), this failed to reach the level of significance (p: 0.063). Evaluation of the Wexner score and the 36-item Short Form Health Survey as well as comparison of patients who remained on TAI (n: 9) versus those who had stopped TAI after 3 months (n: 9) failed to find any statistically significant difference between TAI and ST. CONCLUSIONS: This follow-up study revealed that a considerable number of patients decided to stop TAI within 12 months. However, the number of bowel movements during the day were still lower when TAI was used than when patients had ST only. CATEGORY: Randomized trial. REGISTRATION NUMBER: DRKS00011752, https://apps.who.int/trialsearch/ .

Internal anal sphincter nerves - a macroanatomical and microscopic description of the extrinsic autonomic nerve supply of the internal anal sphincter.

AIM: The internal anal sphincter (IAS) contributes substantially to anorectal functions. While its autonomic nerve supply has been studied at the microscopic level, little information is available concerning the macroscopic topography of extrinsic nerve fibres. This study was designed to identify neural connections between the pelvic plexus and the IAS, provide a detailed topographical description, and give histological proof of autonomic nerve tissue. METHODS: Macroscopic dissection of pelvic autonomic nerves was performed under magnification in seven (five male, two female) hemipelvises obtained from body donors (67-92 years). Candidate structures were investigated by histological and immunohistochemical staining protocols to visualize nerve tissue. RESULTS: Nerve fibres could be traced from the anteroinferior edge of the pelvic plexus to the anorectal junction running along the neurovascular bundle anterolaterally to the rectum and posterolaterally to the prostate/vagina. Nerve fibres penetrated the longitudinal rectal muscle layer just above the fusion with the levator ani muscle (conjoint longitudinal muscle) and entered the intersphincteric space to reach the IAS. Histological and immunohistochemical findings confirmed the presence of nerve tissue. CONCLUSIONS: Autonomic nerve fibres supplying the IAS emerge from the pelvic plexus and are distinct to nerves entering the rectum via the lateral pedicles. Thus, they should be classified as IAS nerves. The identification and precise topographical location described provides a basis for nerve-sparing rectal resection procedures and helps to prevent postoperative functional anorectal disorders.

Structured assessment of laparoscopic camera navigation skills: the SALAS score.

BACKGROUND: Tools are needed to assess laparoscopic camera navigation (LCN) in the operating room. Here, we aimed to develop an objective rating scale for LCN. STUDY DESIGN: We defined the following key aspects of LCN: operational field centering, correct angle of the horizon, correct instrument visualization, verbal commands from the operating surgeon, and manual corrections from the operating surgeon. We then developed a score based on intraoperative error evaluation from intraoperative recordings of 80 procedures. Finally, the newly developed score was validated by four different raters using video-based analysis of 20 elective laparoscopic cholecystectomies. RESULTS: We developed and validated a tool for the structured assessment of laparoscopic assistant skills (SALAS). This score showed good internal consistency, with a Cronbach's alpha of > 0.7. Intraclass correlation revealed a low interrater variability (ICC 0.866) for the total score. Comparison of experienced and inexperienced camera assistants revealed significantly better SALAS scores for experienced assistants (p < 0.05). CONCLUSION: Our present results show that SALAS score is valid, reliable, and practicable. This score can be used for future investigations of camera navigation efficiency and training.

Continuous intraoperative monitoring of pelvic autonomic nerves during TME to prevent urogenital and anorectal dysfunction in rectal cancer patients (NEUROS): a randomized controlled trial.

BACKGROUND: Urinary, sexual and anorectal sequelae are frequent after rectal cancer surgery and were found to be related to intraoperative neurogenic impairment. Neuromonitoring methods have been developed to identify and preserve the complex pelvic autonomic nervous system in order to maintain patients' quality of life. So far no randomized study has been published dealing with the role of neuromonitoring in rectal cancer surgery. METHODS/DESIGN: NEUROS is a prospective two-arm randomized controlled multicenter clinical trial comparing the functional outcome in rectal cancer patients undergoing total mesorectal excision (TME) with and without pelvic intraoperative neuromonitoring (pIONM). A total of 188 patients will be included. Primary endpoint is the urinary function measured by the International Prostate Symptom Score. Secondary endpoints consist of sexual, anorectal functional outcome and safety, especially oncologic safety and quality of TME. Sexual function is assessed in females with the Female Sexual Function Index and in males with the International Index of Erectile Function. For evaluation of anorectal function the Wexner-Vaizey score is used. Functional evaluation is scheduled before radiochemotherapy (if applicable), preoperatively (baseline), before hospital discharge, 3 and 6 months after stoma closure and 12 months after surgery. For assessment of safety adverse events, the rates of positive resection margins and quality of mesorectum are documented. DISCUSSION: This study will provide high quality evidence on the efficacy of pIONM aiming for improvement of functional outcome in rectal cancer patients undergoing TME. TRIAL REGISTRATION: Clinicaltrials.gov: NCT01585727 . Registration date is 04/25/2012.

Electrophysiology-based quality assurance of nerve-sparing in laparoscopic rectal cancer surgery: Is it worth the effort?

BACKGROUND: After low anterior resection for rectal cancer, visual assessment of pelvic autonomic nerve preservation can be difficult due to the complexity of neuroanatomy, as well as surgery- and patient-related factors. The present study aimed to evaluate nerve-sparing quality assurance using the laparoscopic neuromapping (LNM) technique. METHODS: We prospectively investigated a series of 30 patients undergoing laparoscopic low anterior resection. Nerve-sparing was evaluated both visually and electrophysiologically. LNM was performed using stimulation of pelvic autonomic nerves under simultaneous cystomanometry and processed electromyography of the internal anal sphincter. Urogenital and anorectal functions were evaluated using validated and standardized questionnaires preoperatively, at short-term follow-up, and at mid-term follow-up at a median of 9 months (range 6-12 months) after surgery. RESULTS: One patient reported new onset of urinary dysfunction, and another patient reported new onset of anorectal dysfunction. Of the 20 sexually active patients, five reported sexual dysfunction. Visual assessment by laparoscopy confirmed complete nerve preservation in 28 of 30 cases. For prediction of urinary and anorectal function, LNM sensitivity, specificity, positive and negative predictive value, and overall accuracy were each 100 %. LNM with combined assessment for prediction of sexual function yielded a sensitivity of 80 %, specificity of 93 %, positive predictive value of 80 %, negative predictive value of 93 %, and overall accuracy of 90 %. CONCLUSIONS: LNM is an appropriate method for reliable quality assurance of laparoscopic nerve-sparing.

Midterm functional results of taTME with neuromapping for low rectal cancer.

BACKGROUND: Information on functional outcomes after laparoscopic-assisted transanal total mesorectal excision (taTME) is limited. This study analyzed the functional results in patients with low rectal cancer. METHODS: Ten consecutive patients (nine males) undergoing electrophysiologically controlled nerve-sparing taTME were investigated prospectively and asked to complete functional questionnaires [the International Prostate Symptom Score (IPSS), International Index of Erectile Function, Female Sexual Function Index, Wexner score, and low anterior resection syndrome (LARS) score]. Bladder function was also assessed according to residual urine volume. Preoperative function was compared to the functional outcome 3 and 6 months, and 9 months if eligible, after stoma closure or surgery in the absence of a diverting stoma. RESULTS: Prior to therapy, urinary and sexual function was impaired in 40 and 60% of patients, respectively. None of the patients developed pathological residual urine volumes after at least unilateral functional pelvic nerve-sparing. Median IPSS was lower than preoperative scores (p > 0.05). Two males with incomplete nerve preservation were considered impotent during a median follow-up of 15 months (range 6-20 months). The female was judged to be sexually inactive. The median Wexner score was 1 (range 0-7) prior to any therapy and increased to 7 (range 0-15) at 6 months (p = 0.029), with 40% of patients categorized as having no LARS and 50% minor LARS. The median LARS score was 28 (range 9-38) at 3 months and 26 (range 9-32) at 6 months (p = 0.165). CONCLUSIONS: Despite a small sample size and confounding factors, data indicate that taTME has the potential to preserve continence, sufficient bowel function, and urogenital function.

[3D Virtual Reality Laparoscopic Simulation in Surgical Education - Results of a Pilot Study]. / Virtuelle 3-D-Laparoskopie-Simulation in der chirurgischen Aus- und Weiterbildung - Ergebnisse einer Pilotstudie.

BACKGROUND: The use of three-dimensional imaging in laparoscopy is a growing issue and has led to 3D systems in laparoscopic simulation. Studies on box trainers have shown differing results concerning the benefit of 3D imaging. There are currently no studies analysing 3D imaging in virtual reality laparoscopy (VRL). MATERIALS AND METHODS: Five surgical fellows, 10 surgical residents and 29 undergraduate medical students performed abstract and procedural tasks on a VRL simulator using conventional 2D and 3D imaging in a randomised order. RESULTS: No significant differences between the two imaging systems were shown for students or medical professionals. Participants who preferred three-dimensional imaging showed significantly better results in 2D as wells as in 3D imaging. DISCUSSION: First results on three-dimensional imaging on box trainers showed different results. Some studies resulted in an advantage of 3D imaging for laparoscopic novices. This study did not confirm the superiority of 3D imaging over conventional 2D imaging in a VRL simulator. CONCLUSION: In the present study on 3D imaging on a VRL simulator there was no significant advantage for 3D imaging compared to conventional 2D imaging.

Impact of inhalation vs. intravenous anaesthesia on autonomic nerves and internal anal sphincter tone.

BACKGROUND: Pelvic intraoperative neuromonitoring (pIONM) aims to identify and spare the autonomic nerves and maintain patients' quality of life. The effect of anaesthetic agents on the pIONM signal is unknown; therefore, the aim of the present study was to compare the influences of inhalation anaesthesia (IA) and total intravenous anaesthesia (TIVA). METHODS: Twenty rectal cancer patients undergoing open nerve-sparing total mesorectal excision (TME) were assigned to pIONM under either IA or TIVA (n = 10 per group). IA was maintained with sevoflurane and TIVA with propofol. During surgery, pelvic autonomic nerves were electrically stimulated under electromyography (EMG) of the internal anal sphincter (IAS). These triggered EMG signals were analysed. RESULTS: The absolute EMG amplitude during pIONM increased to 1.20 µV (interquartile range (IQR): 0.94-1.6) for IA and 1.49 µV (IQR: 0.84-2.75) for TIVA (P = 0.002). The relative EMG amplitude increase also was significantly lower for IA (0.59; IQR: 0.30-0.81; TIVA: 0.99; IQR: 0.62-2.5), (P = 0.001). CONCLUSIONS: This is the first study to compare the influences of IA and TIVA on the autonomic nervous system. While both anaesthetic regimens proved useful for pIONM, TIVA with propofol may provide better signal quality than IA with sevoflurane.

Preconditioning in laparoscopic surgery--results of a virtual reality pilot study.

BACKGROUND: This prospective study investigated the effect of preconditioning in laparoscopic cholecystectomy (LC) and appendectomy (LA) based on pre- and postoperative virtual reality laparoscopy (VRL) performances, with specific regard to the impact of different motor skills, types of surgery and levels of experience. STUDY DESIGN: Forty laparoscopic procedures (28 LC and 12 LA) were performed by 13 residents in the operating room. Participants completed a defined set of tasks on the VRL simulator directly prior to and after the operation: one preparational task (PT), a virtual procedural task with emphasis on fine preparation (VPT) and a navigational manoeuvre for instrument coordination (ICT). VRL performances were evaluated based on the assessed items of the simulator. RESULTS: Overall analysis of the surgeons' performance demonstrated better postoperative results for PT and VPT in 28 and 26 cases (p = 0.001 and p = 0.034), respectively. No significant difference was found for ICT (p = 0.638). Less-experienced residents had better postoperative results for PT and VPT (p = 0.009 and p = 0.041), whereas more-experienced surgeons had better postoperative results for PT only (p = 0.030). LC resulted in better postoperative performance for PT (p = 0.007). LA improved performance for PT and VPT (p = 0.034 and p = 0.006, respectively). Comparisons of surgeon's experience demonstrated a significant advantage for more-experienced surgeons in ICT (p = 0.033), while type of surgery showed an advantage for LA in VPT (p = 0.022). CONCLUSION: There is a preconditioning effect in laparoscopic surgery. The differing results related to LC and LA and the experience levels of surgeons suggest that differentiated warm-up strategies are required.

[Upper gastrointestinal bleeding and haemorrhagic shock at the end of the holidays: pre-hospital and in-hospital management of a gastrointestinal emergency]. / Obere gastrointestinale Blutung mit hämorrhagischem Schock am Ende einer Urlaubsreise: Präklinische und innerklinische Versorgung eines gastrointestinalen Notfalls.

Upon returning from holidays, a 55-year-old patient presenting with melena and haemorrhagic shock was admitted to a University hospital after receiving first emergency medical care in a German InterCity train. In an interdisciplinary effort, haemodynamics were stabilised and the airway and respiratory function were secured. Under emergency care conditions the patient then underwent an emergency upper GI endoscopy where a spurting arterial upper gastrointestinal bleeding (Forrest 1a) was found. While the bleeding could not be controlled with endoscopic techniques, definitive haemostasis was achieved with a surgical laparotomy. While not commonly established for patients with severe GI bleeding, by spontaneous implementation of an interdisciplinary trauma room approach following established trauma algorithms the team was able to achieve stabilisation of vital functions and final control of bleeding in this highly unstable patient. Although the majority of upper gastrointestinal bleedings spontaneously cease, emergency care algorithms should be developed and implemented for patients with severe gastrointestinal bleedings in shock. Following the case vignette, we discuss a potential approach and develop an exemplary protocol for shock room management in this patient subgroup.

Percutaneous nerve evaluation based on electrode placement under control of autonomic innervation.

BACKGROUND: Foramen needle electrode placement for percutaneous nerve evaluation (PNE) is currently carried out while observing the somatic motor response. This study investigated electrode placement while observing the autonomic as well as the somatic response. METHODS: A consecutive series of ten patients (seven women) with a median age of 51.9 (range 30-75) years undergoing PNE for faecal incontinence (n = 6) and obstipation (n = 4) were investigated prospectively. Electrode placement was carried out under simultaneous electromyography (EMG) of the external anal sphincter (EAS) and internal anal sphincter (IAS) and cystomanometry. RESULTS: PNE under control of somatic and autonomic nerve responses was carried out in all patients. In three out of ten patients, initial needle electrode placement showed single evoked EMG signals from the EAS. Final electrode placement resulted in adequate somatic motor and autonomic responses in all patients. Comparison of the increases in IAS EMG amplitude on the right and left stimulation sites for sacral nerves S3 and S4 demonstrated significant differences [S3 right: median 15.3 (interquartile range (IQR) 10.4; 20.1) µV vs. S3 left: median 11.6 (IQR 8.6; 16.0) µV, p = 0.034 and S4 right: median 24.1 (IQR 20.1; 37.2) µV vs. S4 left: median 12.0 (IQR 10.7; 13.7) µV, p = 0.012]. Stimulation-induced bladder activation was achieved in all seven patients with concomitant urinary dysfunction. CONCLUSIONS: Control of not just the somatic motor response but also the autonomic nerve response during foramen needle electrode placement may objectify PNE.

Evaluation of two-dimensional intraoperative neuromonitoring for predicting urinary and anorectal function after rectal cancer surgery.

PURPOSE: The aim of this study was to compare the results of two-dimensional intraoperative neuromonitoring (IONM) with the postoperative urinary and anorectal function of rectal cancer patients. METHODS: A consecutive series of 35 patients undergoing low anterior resection were investigated prospectively. IONM was performed with electric stimulations of the pelvic splanchnic nerves under simultaneous manometry of the bladder and electromyography (EMG) of the internal anal sphincter (IAS). Urinary and anorectal function were evaluated preoperatively and at follow-up by standardized questionnaires, digital rectal examination scoring system, and long-term catheterization rate. RESULTS: The rate of postoperative newly developed bladder dysfunction was 17 %. IONM with bladder manometry had a sensitivity of 100 %, specificity of 96 %, positive predictive value of 83 %, negative predictive value of 100 %, and overall accuracy of 97 %, respectively. The proportion of patients with severely impaired anorectal function at follow-up was 8 %. The sensitivity, specificity, and positive and negative predictive values for IONM with EMG of the IAS were, respectively, 100, 96, 67, and 100 % with an accuracy of 96 %. The degree of agreement for IONM with EMG of the IAS was good for anorectal function (к = 0.780) and poor for urinary function (к = 0.119). IONM with bladder manometry yielded a very good degree of agreement for urinary function (к = 0.891) and a fair agreement for anorectal function (к = 0.336). CONCLUSIONS: The two-dimensional IONM method is suitable for verification of bladder and IAS innervation. Accurate prediction of urinary and anorectal function necessitates both bladder manometry and EMG of the IAS.

[Surgical therapy of segmental jejunal, primary intestinal lymphangiectasia]. / Die operative Therapie einer segmentalen, primären intestinalen Lymphangiektasie des Jejunums mit ausgeprägtem Chylaskos.

Primary intestinal lymphangiectasia (PIL) is a protein-losing, exsudative gastroenteropathy causing lymphatic obstruction. Diagnosis depends on clinical examination and histological findings. Conservative treatment modalities include a low-fat diet and enteral nutritional therapy in order to reduce enteric protein loss and to improve fat metabolism. Other treatment options consist of administration of antiplasmin or octreotide to lower lymph flow and secretion. We report on a 58-year-old patient who underwent exploratory laparotomy due to a worsening physical status, recurrent chylaskos and leg oedema under conservative dietary therapy. Intraoperative findings showed a typical PIL of the jejunum about 20 cm distal to the Treitz's ligament. Histological examinations confirmed this diagnosis. One year after segmental small bowel resection (105 cm) with end-to-end anastomosis the patient is healthy, free of symptoms, has gained weight and his serum protein level has increased. Intraabdominal ascites and leg oedema have not reoccurred since.

Continuous intraoperative monitoring of autonomic nerves during low anterior rectal resection: an innovative approach for observation of functional nerve integrity in pelvic surgery.

PURPOSE: The aim of this study was to develop a methodological setup for continuous intraoperative neuromonitoring with intent to improve nerve-sparing pelvic surgery. METHODS: Fourteen pigs underwent low anterior rectal resection. Continuous stimulation of pelvic autonomic nerves was carried out with a newly developed tripolar surface electrode during lateral, anterolateral, and anterior mesorectal dissection. Neuromonitoring was performed under electromyography of the autonomic innervated internal anal sphincter. RESULTS: Continuous neuromonitoring resulted in significantly increased electromyographic amplitudes of the internal anal sphincter, confirming intact innervation throughout the whole dissection in each animal (median 0.9 µV, interquartile range 0.5; 1.5 vs. median 3.4 µV, interquartile range 2.1; 4.7) (p < 0.001). The median dissection time in each animal was 10 min within a median number of ten (range 8-13) tripolar electric stimulations. CONCLUSION: The present study is the first to demonstrate that continuous intraoperative monitoring of pelvic autonomic nerves during low anterior rectal resection is feasible.

Online signal processing of internal anal sphincter activity during pelvic autonomic nerve stimulation: a new method to improve the reliability of intra-operative neuromonitoring signals.

AIM: Intra-operative neuromonitoring is increasingly applied in several surgical disciplines and has been introduced to facilitate pelvic autonomic nerve preservation. Nevertheless, it has been considered a questionable tool for the minimization of risk, as the results are variable and might be misleading. The aim of the present experimental study was to develop an intra-operative neuromonitoring system with improved reliability for monitoring pelvic autonomic nerve function. METHOD: Fifteen pigs underwent low anterior rectal resection with pelvic autonomic nerve preservation. Intra-operative neuromonitoring was performed under autonomic nerve stimulation with observation of electromyographic signals of the internal anal sphincter and bladder manometry. As the internal anal sphincter frequency spectrum during stimulation was found to be mainly in the range of 5-20 Hz, intra-operative neuromonitoring signals were postoperatively processed by implementation of matching band pass filters. RESULTS: In 10 preliminary experiments, signal processing was performed offline in the postoperative analysis. Of 163 stimulations intra-operatively assessed by the surgeon as positive responses, 135 (83%) were confirmed after signal processing. In the following five consecutive experiments intra-operative online signal processing was realized and demonstrated reliable intra-operative neuromonitoring signals of internal anal sphincter activity with significant increase during pelvic autonomic nerve stimulation [0.5 µV (interquartile range = 0.3-0.7) vs 4.8 µV (interquartile range = 2.5-7.5); P < 0.001]. CONCLUSION: Online signal processing of internal anal sphincter activity aids reliable identification of pelvic autonomic nerves with potential for improvement of intra-operative neuromonitoring in pelvic surgery.

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.

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

OBJECTIVE: Restorative proctectomy with straight coloanal anastomosis (CAA) and restorative proctocolectomy with ilealpouch-anal anastomosis (IPAA) are options for maintaining bowel integrity after rectal resection. The aim of this study was to compare clinical function and anorectal physiology in patients treated with CAA and IPAA. METHOD: Three-dimensional vector-manometry and neorectal volumetry were performed in straight CAA [53 patients (34 male)] and IPAA [61 patients (39 male)] for ulcerative colitis. Function was assessed using a 14 day incontinence diary. RESULTS: Function was similar in both groups, but neorectal compliance and threshold volumes for sensation, urge and maximum tolerated volume (MTV) were significantly higher after IPAA than after CAA. Mean pressure, vector volume and sphincter symmetry at rest were significant determinants of continence in both groups but squeeze pressure did not correlate significantly with function in either group. Threshold volume, MTV, and compliance were significantly correlated with frequency of defecation in patients with IPAA but not with CAA. CONCLUSION: A strong consistent resting anal sphincter pressure is one determinant of continence after both IPAA and CAA. Squeeze pressures do not influence the functional result. In IPAA but not CAA, the neorectum has a reservoir function which correlates with the postoperative frequency of defaecation.

Randomized clinical trial of prophylactic transanal irrigation versus supportive therapy to prevent symptoms of low anterior resection syndrome after rectal resection.

Background: Low anterior resection syndrome (LARS) is a frequent problem after rectal resection. Transanal irrigation (TAI) has been suggested as an effective treatment in patients who have developed LARS. This prospective RCT was undertaken to evaluate the effect of TAI as a prophylactic treatment to prevent symptoms of LARS. Methods: Patients who had undergone ultralow rectal resection were randomized to start TAI on a daily basis, or to serve as a control with supportive therapy only after ileostomy closure. All patients were seen after 1 week, 1 month and 3 months, and the maximum number of defaecation episodes per day and night documented during follow-up. Wexner score, LARS score and Short Form 36 questionnaire responses were evaluated in both groups. Results: Thirty-seven patients could be evaluated according to protocol (TAI 18, control 19). The maximum number of stool episodes per day and per night was significantly lower among patients who underwent TAI at 1 month (median 3 versus 7 episodes/day in TAI versus control group, P = 0·003; 0 versus 3 episodes/night, P = 0·001) and 3 months (3 versus 5 episodes per day, P = 0·006; 0 versus 1 episodes/night, P = 0·002). LARS scores were significantly better in the TAI group after 1 month (median 16 versus 32 in control group; P = 0·044) and 3 months (9 versus 31; P = 0·001). A significantly better result in terms of Wexner score was seen in the TAI group after 3 months (median 2 versus 6 in controls; P = 0·046). Conclusion: Prophylactic TAI led to a significantly better functional outcome compared with supportive therapy for up to 3 months. Registration number: DRKS00011752 ( http://apps.who.int/trialsearch/).