Sacral nerve stimulation in patients with ileal pouch-anal anastomosis.

PURPOSE: Functional results after proctocolectomy and ileal pouch-anal anastomosis (IPAA) are generally good. However, some patients suffer from high stool frequency or fecal incontinence. Sacral nerve stimulation (SNS) may represent a therapeutic alternative in these patients, but little is known about indication and results. The aim of this study was to evaluate incontinence after IPAA and demonstrate SNS feasibility in these patients. METHODS: This retrospective study includes patients who received a SNS between 1993 and 2020 for increased stool frequency or fecal incontinence after proctocolectomy with IPAA for ulcerative colitis. Proctocolectomy was performed in a two- or three-step approach with ileostomy closure as the last step. Demographic, follow-up data and functional results were obtained from the hospital database. RESULTS: SNS was performed in 23 patients. Median follow-up time after SNS was 6.5 years (min. 4.2-max. 8.8). Two patients were lost to follow-up. The median time from ileostomy closure to SNS implantation was 6 years (min. 0.5-max. 14.5). Continence after SNS improved in 16 patients (69%) with a median St. Marks score for anal incontinence of 19 (min. 4-max. 22) before SNS compared to 4 (0-10) after SNS placement (p = 0.012). In seven patients, SNS therapy was not successful. CONCLUSION: SNS implantation improves symptoms in over two-thirds of patients suffering from high stool frequency or fecal incontinence after proctocolectomy with IPAA. Awareness of the beneficial effects of SNS should be increased in physicians involved in the management of these patients.

Stapled intestinal anastomoses are more cost effective than hand-sewn anastomoses in a diagnosis related group system.

PURPOSE: Creation of an optimal bowel anastomosis with low postoperative leakage rate is an immanent part of colorectal surgery contributing to recovery, length of hospital stay and overall hospital costs. We aimed to investigate costs of small and large bowel resection, length of hospital stay, anastomotic leakage rate and its risk factors depending on the anastomotic technique. METHODS: Retrospective analysis of 198 patients (67 stapled and 131 hand-sewn anastomoses) undergoing elective bowel resection with a single anastomosis without protective ileostomy either stapled or in double-rowed running suture technique between 1st October 2012 and 30th September 2018 at Charité University Hospital Berlin, Campus Benjamin Franklin. We analyzed costs of treatment, total length of hospital stay, rate of anastomotic leakage and possible risk factors for anastomotic leak. RESULTS: No significant difference between both anastomotic techniques could be detected for hospital stay (p = 0.754), 30-day-readmission rate (p = 0.827), or anastomotic leakage (p = 606). Neither comorbidities (p = 0.449), underlying disease (p = 0.132), experience of the surgical team (p = 0.828) nor scheduling of the operation (p = 0.531) were associated with anastomotic leakage. Stapled anastomoses took 22 min less operation time than sutured anastomoses (130 vs. 152 min. Median) (p = 0.001). Operations with stapled anastomoses saved 183 € in operation costs and 496 € in overall hospital costs. CONCLUSION: Stapled and hand-sewn bowel anastomoses can be performed equally safe without differences in postoperative outcome. No patient, procedure or surgeon related risk factors for anastomotic leakage could be detected. Bowel resections with stapled anastomoses take less time and save operation and overall hospital costs.

Influence of interapplicator distance on multibipolar radiofrequency ablation during physiological and interrupted liver perfusion in an in vivo porcine model.

Radiofrequency ablation (RFA) is a curative treatment option for early stage hepatocellular carcinoma (HCC). Vascular inflow occlusion to the liver (Pringle manoeuvre) and multibipolar RFA (mbRFA) represent possibilities to generate large ablations. This study evaluated the impact of different interapplicator distances and a Pringle manoeuvre on ablation area and geometry of mbRFA. 24 mbRFA were planned in porcine livers in vivo. Test series with continuous blood flow had an interapplicator distance of 20 mm and 15 mm, respectively. For a Pringle manoeuvre, interapplicator distance was predefined at 20 mm. After liver dissection, ablation area and geometry were analysed macroscopically and histologically. Confluent and homogenous ablations could be achieved with a Pringle manoeuvre and an interapplicator distance of 15 mm with sustained hepatic blood flow. Ablation geometry was inhomogeneous with an applicator distance of 20 mm with physiological liver perfusion. A Pringle manoeuvre led to a fourfold increase in ablation area in comparison to sustained hepatic blood flow (p < 0.001). Interapplicator distance affects ablation geometry of mbRFA. Strict adherence to the planned applicator distance is advisable under continuous blood flow. The application of a Pringle manoeuvre should be considered when compliance with the interapplicator distance cannot be guaranteed.

Novel methods for in vitro modeling of pancreatic cancer reveal important aspects for successful primary cell culture.

BACKGROUND: Pancreatic cancer remains a fatal disease. Experimental systems are needed for personalized treatment strategies, drug testing and to further understand tumor biology. Cell cultures can serve as an excellent preclinical platform, but their generation remains challenging. METHODS: Tumor cells from surgically removed pancreatic ductal adenocarcinoma (PDAC) specimens were cultured under novel protocols. Cellular growth and composition were analyzed and culture conditions were continuously optimized. Characterization of cell cultures and primary tumors was performed via hematoxylin and eosin (HE) and immunofluorescence (IF) staining. RESULTS: Protocols for two- and three-dimensional PDAC primary cell cultures could successfully be established. Primary cell culture depended on dissociation techniques, growth factor supplementation and extracellular matrix components containing Matrigel being crucial for the transformation to three-dimensional PDAC organoids. The generated cultures showed to be highly resemblant to established PDAC primary cell cultures. HE and IF staining for cell culture and corresponding primary tumor characterization could successfully be performed. CONCLUSIONS: The work presented herein shows novel and effective methods to successfully establish primary PDAC cell cultures in a distinct time frame. Factors contributing to cell growth and differentiation could be identified with important implications for further primary cell culture protocols. The established protocols might serve as novel tools in personalized tumor therapy.

Colectomy with ileostomy for severe ulcerative colitis-postoperative complications and risk factors.

PURPOSE: In the era of biological therapy of ulcerative colitis (UC), surgical treatment frequently consists of colectomy, end ileostomy, and rectal stump closure before patients go on towards restorative proctocolectomy. We aimed to evaluate possible risk factors for the occurrence of postoperative complications and investigate those after initial colectomy in these patients. METHODS: Retrospective analysis of 180 patients (76 female, 104 male) undergoing colectomy for UC with formation of a rectal stump and terminal ileostomy between March 2008 and March 2018 at Charité University Hospital Berlin, Campus Benjamin Franklin. A panel of possible postoperative complications was established, patient history was screened, and postoperative complications were analyzed using the Clavien Dindo Classification. RESULTS: Postoperative complication rate was 27.7%. Mortality was 0.5%. Postoperative ileus occurred in 15.3% and rectal stump leakage in 14.8%. Complications were categorized as Clavien Dindo 3 in 80%. Risk factors for surgical complications after multivariate analysis were ASA classification (p = 0.004), preoperative anemia (Hemoglobin < 8 mg/dl) (p = 0.025), use of immunosuppressants (p = 0.003), more than two cardiovascular diseases (p = 0.016), and peritonitis (p = 0.000). Reoperation rate of patients with surgical complications was 27.7%. CONCLUSION: Colectomy in high-risk UC patients is associated with significant morbidity. However, most of the surgical complications can be treated conservatively. Overall mortality is low. Patient-related risk factors are associated with postoperative complications. Optimizing these risk factors or earlier indication for surgery in the course of UC may help to reduce morbidity of this procedure.

[Transanal total mesorectal excision-a critical appraisal]. / Transanale totale mesorektale Exzision ­ eine kritische Standortbestimmung.

INTRODUCTION: Total mesorectal excision (TME) is the international standard for rectal cancer surgery. In addition to laparoscopic TME (lapTME), transanal TME (taTME) was developed in recent years to reduce the rate of incomplete TME, conversion to open surgery and postoperative functional impairment. Despite limited evidence, this technique is becoming increasingly more popular and is already routinely used by many hospitals for rectal cancer in varying tumor level locations. The aim of this review was to evaluate the taTME compared to anterior rectal resection with lapTME as the standard of care in rectal cancer surgery based on currently available evidence. METHOD: The databases PubMed and Medline were systematically searched for publications on transanal total mesorectal excision (taTME) and transanal minimally invasive surgery (TAMIS). Relevant studies were selected and further research based on the reference lists was undertaken. RESULTS: A total of 16 studies analyzing 3782 patients were identified. The taTME does not lead to a higher rate of complete TME-resected specimens compared to the standard procedure. So far, superiority could not be demonstrated for complication rates or for functional or oncological results. Serious complications secondary to dissection in incorrect planes were observed. The anastomotic level generally seems to be closer to the sphincter after taTME versus anterior lapTME. CONCLUSION: Considering current evidence, taTME failed to show superiority compared to conventional anterior lapTME. Although taTME has some potential advantages, it carries substantial risks. If performed outside of clinical trials, it should therefore only be used in carefully selected patients with a high possibility of conversion, following adequate patient informed consent and after intense and systematic training of the surgeon.

The adipofasciocutaneous gluteal fold perforator flap a versatile alternative choice for covering perineal defects.

AIM: Perineal defects following the resection of anorectal malignancies are a reconstructive challenge. Flaps based on the rectus abdominis muscle have several drawbacks. Regional perforator flaps may be a suitable alternative. We present our experience of using the gluteal fold flap (GFF) for reconstructing perineal and pelvic defects. METHODS: We used a retrospective chart review and follow-up examinations focusing on epidemiological, oncological (procedure and outcome), and therapy-related data. This included postoperative complications and their management, length of hospital stay, and time to heal. RESULTS: Twenty-two GFFs (unilateral n = 8; bilateral n = 7) were performed in 15 patients (nine women and six men; anal squamous cell carcinoma n = 8; rectal adenocarcinoma n = 7; mean age 65.5 + 8.2 years) with a mean follow-up time of 1 year. Of the cases, 73.3% were a recurrent disease. Microscopic tumor resection was achieved in all but one case (93.3%). Seven cases had no complications (46.7%). Surgical complications were classified according to the Clavien-Dindo system (grades I n = 2; II n = 2; IIIb n = 4). These were mainly wound healing disorders that did not affect mobilization or discharge. The time to discharge was 22 + 9.9 days. The oncological outcomes were as follows: 53.3% of the patients had no evidence of disease, 20% had metastatic disease, 20% had local recurrent disease, and one patient (6.7%) died of other causes. CONCLUSIONS: The GFF is a robust, reliable flap suitable for perineal and pelvic reconstruction. It can be raised quickly and easily, has an acceptable complication rate and donor site morbidity, and does not affect the abdominal wall.

Radiological Changes After Resection Rectopexy in Patients with Rectal Prolapse-Influence on Clinical Symptoms and Quality of Life.

BACKGROUND: Resection rectopexy is performed to correct the anatomic defect associated with rectal prolapse. The aim of the study was to determine whether the change in the radiological prolapse grade has an influence on patients' symptoms and quality of life. METHODS: The study investigated 40 patients who underwent resection rectopexy for rectal prolapse. The following were determined before and after surgery: radiological prolapse grade, anorectal angle and pelvic floor position in defecography, clinical symptoms (Cleveland Clinic Incontinence and Constipation Scores, Kelly-Hohlschneider Score), quality of life. RESULTS: Defecography revealed postoperative improvement in the prolapse grade and pelvic floor position (p < 0.05). The clinical symptoms and quality of life improved in both, the total population (n = 40) and in patients with improved radiological prolapse grade (n = 30): all clinical scores (p < 0.05), SF-36 (vitality, social role, mental health p < 0.05), and Fecal Incontinence Quality of Life Scale (lifestyle, coping, embarrassment p < 0.05). Patients without improved radiological findings showed no change in their symptoms or quality of life. CONCLUSION: Our study demonstrates that the radiological prolapse grade is improved by resection rectopexy. Correction of the anatomic defect was associated with improvement in symptoms and quality of life. Defecography may therefore be useful in the postoperative assessment of persistent symptoms or reduced quality of life.

Influence of pelvic volume on surgical outcome after low anterior resection for rectal cancer.

BACKGROUND: Low anterior resection (LAR) for rectal cancer is a potentially challenging operation due to limited space in the pelvis. CT pelvimetry allows to quantify pelvic space, so that its relationship with outcome after LAR may be assessed. Studies investigating this, however, yielded conflicting results. We hypothesized that a small pelvis is associated with a higher rate of incomplete mesorectal excision, anastomotic leakages, and increased rate of urinary dysfunction in patients operated for rectal cancer. METHODS: In a single-center retrospective analysis, we studied 74 patients that underwent LAR for rectal cancer with primary anastomosis. Thin-layered multi-slice CT datasets were used for slice by slice depiction of the inner pelvic surface, and the inner pelvic volume was automatically compounded. The primary outcome was quality of total mesorectal excision (TME; Mercury grading); secondary outcomes were anastomotic leakage and urinary dysfunction with regard to pelvic dimensions. Univariate analyses and multiple logistic regression analyses were performed for the primary and the secondary outcomes. RESULTS: Shorter obstetric conjugate diameters were associated with a higher probability of a worse TME quality (110.8 ± 10.2 vs. 105.0 ± 8.6 mm; OR 0.85; 95% CI 0.73-0.99; p = 0.038). Short interspinous distance showed a trend towards an increased risk for deteriorated TME quality (OR 0.88; 95% CI 0.76-1.0; p = 0.06). Anastomotic leakage was associated with anemia (OR 2.77; 95% CI 1.0-7.7; p = 0.047). Association between pelvic diameters or pelvic volume and anastomotic leakage or urinary dysfunction was not observed. Perioperative blood transfusions were administered more often in patients with postoperative urinary dysfunction (OR 17.67; 95% CI 2.44-127.7; p = 0.004). CONCLUSION: Shorter obstetric conjugate diameter might be a risk factor for incompleteness of total mesorectal excision. Anastomotic leakage seems to be influenced more by clinical factors such as anemia rather than pelvic dimensions. Further studies have to prove the influence of pelvic diameter on local recurrence of rectal cancer after LAR.

Risk factors for reoperation after ileostomy reversal - Results from a prospective cohort study.

BACKGROUND: Ileostomy reversal is frequently performed in abdominal surgery. Postoperative complications after ileostomy reversal are encountered in around 20% of patients. Data regarding risk factors for reoperation after ileostomy closure are scarce. The purpose of this prospective trial was to determine risk factors for operative revision after ileostomy closure. MATERIALS AND METHODS: This is an additional post hoc analysis of a two center prospective trial. After enrollment, patient characteristics and intraoperative details were analyzed. Patients were followed up at one postoperative visit before discharge and at a three months postoperative visit by standardized questionnaire. All reoperations occurring in the three months period after surgery were analyzed, and immediate reoperations which were directly related to the ileostomy reversal were analyzed separately. RESULTS: 118 patients with elective ileostomy reversal were included in the trial. 12 out of 106 patients (11.3%) underwent any reoperation within three months after surgery (Clavien-Dindo grade IIIb). On multivariate analysis, anemia was associated with any reoperation p = 0.004; OR 6.93 (95% CI 1.37-30.07). Six out of 114 patients (5.3%) required an immediate reoperation (small bowel perforation, anastomotic leakage, postoperative ileus, deep wound infection) due to surgical complications directly related to the ileostomy reversal. Higher body mass index and anemia were associated with immediate reoperations (BMI: p = 0.038; OR 0.73 (95% CI 0.55-0.98); anemia: p = 0.001; OR 25.50 (95% CI 3.87-168.21). CONCLUSION: Surgical complications after ileostomy reversal occurred to a substantial extent. Rate of reoperations was associated with anemia and high body mass index. Optimizing patients in terms of preoperative hemoglobin and BMI may reduce surgical complications after ileostomy closure.

Differential activation of afferent neuronal and inflammatory pathways during small bowel obstruction (SBO).

BACKGROUND: Small bowel obstruction (SBO) is a potentially life-threatening condition which may be caused by a variety of pathologies such as postoperative adhesions or malignant diseases. Little is known on alterations in gut physiology during SBO, although its comprehension is essential to improve treatment which may help to prevent subsequent organ failure prior to surgical resolution. We aimed to investigate afferent nerve sensitivity and intestinal inflammatory response during SBO to identify possible targets of treatment. METHODS: C57Bl6 mice were anesthetized, and a midline laparotomy was performed. A small bowel loop was ligated 5 cm proximal to ileo-cecal valve to induce SBO. Control animals received a sham midline laparotomy. SBO animals and controls were sacrificed after 3, 9, or 24 h (each n = 6). A dilated segment of small intestine located 1.5 cm oral to the ligature was prepared for multi-unit mesenteric afferent nerve recordings in vitro. Histological assessment of leukocyte infiltration was performed by myeloperoxidase (MPO). Pro-inflammatory cytokine expression was quantified by RT-PCR. Data are mean ± SEM. KEY RESULTS: Afferent firing to serosal 5-HT (500 µM) peaked at 3.9 ± 0.2 impulse/s 24 h after induction of SBO compared to 2.4 ± 0.1 impulse/s in sham controls (p < 0.05). Serosal bradykinin (0.5 µM) led to an increase in peak afferent firing of 5.3 ± 0.5 impulse/s in 24 h SBO animals compared to 3.5 ± 0.2 impulse/s in sham controls (p < 0.05). No differences in 5-HT and BK sensitivity were observed in 3 and 9 h SBO animals compared to controls. Continuous mechanical ramp distension of the intestinal loop was followed by a pressure-dependent rise in afferent nerve discharge that was reduced in 3 h SBO animals compared to sham controls (p < 0.05). MPO stains showed a rise in leukocyte infiltration of the intestine in SBO animals at 9 and 24 h (p < 0.05). Il-6 but not TNF-a gene expression was increased at 9 and 24 h in SBO animals compared to sham controls (p < 0.05). CONCLUSIONS & INFERENCES: Afferent nerve sensitivity is increased 24 h after induction of SBO. SBO led to a delayed onset intestinal inflammatory response. Inflammatory mediators released during this inflammatory response may be responsible for a later increase in afferent sensitivity. Agents with anti-inflammatory action may, therefore, have a beneficial effect during SBO and may subsequently help to prevent possible organ dysfunction.

Necessity of subcutaneous suction drains in ileostomy reversal (DRASTAR)-a randomized, controlled bi-centered trial.

PURPOSE: Data regarding length of hospital stay of patients undergoing ileostomy reversal are very heterogeneous. There are many factors that may have an influence on the length of postoperative hospital stay, such as postoperative wound infections. One potential strategy to reduce their incidence and to decrease hospital stay is to insert subcutaneous suction drains. The purpose of this study was to examine the influence of the insertion of subcutaneous suction drains on hospital stay and postoperative wound infections in ileostomy reversal. Risk factors for postoperative wound infection were determined. METHODS: This is a randomized controlled two-center non-inferiority trial with two parallel groups. The total length of hospital stay as primary endpoint and the occurrence of a surgical site infection, the colonization of the abdominal wall with bacteria, and the occurrence of hematomas/seromas as secondary endpoints were monitored. RESULTS: One hundred eighteen patients with elective ileostomy reversal were included. Fifty-nine patients were randomly assigned to insertion of a subcutaneous suction drain, and 59 patients were randomly assigned to receive no drain. After 3 months of follow-up, 50 patients in the group with drain and 53 patients in the group without drain could be analyzed. Median total length of hospital stay was 8 days in the SD group and 9 days in the group without SD (p = 0.17). Fourteen percent of patients with SD and 17 % without SD developed SSI, p = 0.68. Multivariate analysis revealed anemia (p < 0.01), intraoperative bowel perforation (p = 0.02) and resident (p = 0.04) or fellow (p = 0.048) performing the operation as risk factors for SSI. CONCLUSIONS: This trial shows that the omission of subcutaneous suction drains is not inferior to the use of subcutaneous suction drains after ileostomy reversal in terms of length of hospital stay, surgical site infections, and hematomas/seromas.

[Watchful waiting vs surgical repair of oligosymptomatic incisional hernias: Current status of the AWARE study]. / Beobachtung vs. Operation oligosymptomatischer Narbenhernien : Aktueller Stand der AWARE-Studie.

INTRODUCTION: Incisional hernias are one of the the most frequent complications in visceral surgery and incisional hernia repair has a relevant complication rate. Therefore, there have to be solid indications before carrying out incisional hernia repair. To date, there is a lack of evidence concerning the correct indications for surgical repair of incisional hernias. The AWARE trial compares watchful waiting to surgical repair of incisional hernias. MATERIAL AND METHODS: The AWARE trial is a prospective randomized multicenter trial. Patients with asymptomatic or oligosymptomatic incisional hernia are randomized into the watchful waiting or the surgical repair group with a follow-up of 2 years. The primary endpoint is pain during normal activities due to the hernia or the hernia repair after 2 years measured on the hernia-specific surgical pain scale (SPS). RESULTS: In this study 36 centers are participating throughout Germany, more than 1600 patients had been screened up to 31 December 2014 and 234 (14.6%) of the screened patients could be recruited. CONCLUSION: The AWARE study will provide evidence concerning the two therapeutic options of watchful waiting and surgical repair of incisional hernia.

Impact of intraoperative microperfusion assessment with Pinpoint Perfusion Imaging on surgical management of laparoscopic low rectal and anorectal anastomoses.

AIM: Inadequate intestinal blood flow may contribute to anastomotic leakage accounting for substantial morbidity and mortality in colorectal surgery. Precise intraoperative assessment of microperfusion may have an impact on the surgeons intraoperative management and leakage rate. METHOD: In this single center observational study we implemented and integrated intraoperative indocyanin green (ICG) based microperfusion assessment of anastomosis with Pinpoint Perfusion Imaging in a series of consecutive rectal cancer patients who underwent laparoscopic anterior and lower anterior resection with primary anastomosis during a 5-months period. RESULTS: We could demonstrate the feasibility and safety of intraoperative fluorescence angiography for colorectal microperfusion assessment. Technology implementation was immediately successful. No adverse effects have been documented related to fluorescent dye. Microperfusion angiography of the colon succeeded in all cases and assessment of perfusion imaging influenced surgical decision making in 28% of the patients, of which all patients showed primary healing of the anastomosis. We found a leakage rate of 6% with one leakage of a coloanal anastomosis in all patients. CONCLUSION: Fluorescence angiography is an accurate tool for assessing microperfusion and is most likely associated with improved outcomes with regard to anastomotic healing.

[Spincter preservation after selective chemoradiotherapy of rectal cancer. Interim results of the OCUM study]. / Spinktererhalt nach selektiver Radiochemotherapie des Rektumkarzinoms. Zwischenergebnisse der OCUM-Studie.

BACKGROUND: In a prospective multicenter observational study (OCUM) neoadjuvant chemoradiotherapy (nRCT) was selectively administered depending on the risk of local recurrence and based on the distance between tumor and mesorectal fascia in pretherapeutic high-resolution magnetic resonance imaging (MRI). OBJECTIVE: Frequency and quality of abdominoperineal excision (APE) and sphincter preserving operations. PATIENTS AND METHODS: Of 642 patients treated in 13 hospitals 389 received surgery alone and 253 nRCT followed by surgery. By univariate and multivariate analysis risk factors for APE were determined. Quality parameters were the quality grade of mesorectal excision, the pathohistological involvement of the circumferential resection margin and intraoperative local dissemination of tumor cells. RESULTS AND DISCUSSION: In 12.8 % of the patients APE was performed. Independent risk factors for APE were tumor location in the lower third of the rectum and the individual hospitals, where APE varied between 0 and 32 %. This variation was chiefly caused by the different case mix. Hospitals with a high APE rate (> 30 %) treated significantly more patients with very low lying carcinomas (< 3 cm above the anal verge) and more advanced tumors. The median height of the tumor in cases of APE was nearly equal in all participating hospitals. Independent on the number of cases the quality of rectal surgery was high. Within the patient groups of primary surgery and nRCT the oncological quality parameter did not significantly differ between sphincter preservation and APE. As far as sphincter preservation is concerned the results justify a selective application of nRCT in patients with rectal carcinoma. The long-term results still have to be awaited.

[Lymph node dissection after primary surgery and neoadjuvant radiochemotherapy of rectal cancer. Interim analysis of a multicenter prospective observational study (OCUM)]. / Lymphknotendissektion nach primärer Chirurgie und neoadjuvanter Radiochemotherapie des Rektumkarzinoms. Interimsanalyse einer multizentrischen prospektiven Beobachtungsstudie (OCUM).

INTRODUCTION: The OCUM trial (NCT01325649) aims to clarify whether low rates of local recurrence are also achieved when the indications for neoadjuvant radiochemotherapy are not based on the clinical TNM staging but on preoperative magnetic resonance imaging with measurement of the tumor distance to the circumferential resection margin. In this interim analysis the lymph node status in OCUM patients was investigated as a surrogate parameter for quality of surgery and histopathological work-up. MATERIAL AND METHODS: Until now a total of 560 patients have been included in this study. Total mesorectal excision (TME) without pretreatment was undertaken in 338 patients (60.4 %) and neoadjuvant radiochemotherapy was administered in 222 (39.6 %) patients. The histological work-up was performed according to the guidelines of the German Association of Pathologists. Data are given as median values and ranges in brackets. RESULTS: The lymph node yield was 24 (7-79) in 338 patients undergoing primary TME surgery without pretreatment, while 20 (3-56) lymph nodes were identified in patients after neoadjuvant radiochemotherapy (p = 0.001). A minimum of 12 lymph nodes were analyzed in 335 out of 338 patients (99.1 %) and in 209 out of 222 patients (94.1 %) following neoadjuvant radiochemotherapy (p = 0.001). Lymph node metastasis was identified (p = 0.362) in 116 out of 338 patients without pretreatment (34.3 %) and in 71 out of 222 patients after neoadjuvant radiochemotherapy (32.0 %). Patient age did not influence the number of identified lymph nodes or rate of lymph node metastasis. CONCLUSION: In this trial the number of identified lymph nodes suggests that the quality of surgery and histopathological work-up were adequate compared to the standards defined by national guidelines. Neoadjuvant radiochemotherapy led to a reduced lymph node yield compared to surgery without pretreatment; however, this did not influence the rate of lymph node metastasis.