To access the transformation effects, the data of 237 patients who underwent surgical treatment with a colorectal cancer in the Westküstenklinikum Heide and Brunsbüttel gGmbH in the period from 01/2012 to 12/2014 were prospectively recorded and retrospectively evaluated. The data was collected as part of the certification process for the colon cancer center (DKG, OnkoZert). After completion of the certification in 2013, the data collection was continued in the same way as the key figure sheets (excerpt of the key figure sheet 2014 see appendix). All patients included had consented to the collection and use of the collected data as part of the inpatient treatment contract (see appendix for excerpt of treatment contract). The tumor staging and the surgical procedure corresponded to the quality requirements of the professional societies and the current guidelines. The study was carried out with the approval of the responsible ethics committee (AZ 15-341A).
Applicable inclusion criteria were the presence of colorectal cancer and open or laparoscopic oncological curative resection of the tumor. The patient collective was divided into two groups. Group A included the laparoscopically operated patients and group B the patients who were treated conventionally via a midline laparotomy. The allocation to the groups was decided by the surgeon. In the further differentiation, a distinction was made between colon and rectal tumors to show differentiated course and quality parameters. In addition to demographic data, general and specific anamnestic parameters were recorded and evaluated. General medical history data collection included: Chronic obstructive pulmonary disease (COPD), myocardial infarction (MI), diabetes mellitus (DM), arterial hypertension (AHT), coronary artery disease (CHD), wound healing disorders in pre-op (WHD), hyperlipoproteinemia (HLP), prostate diseases (PD) and sleep apnea (SAP). The specific anamnestic data record included pre-existing underlying malignant diseases and previous abdominal operations. Furthermore, peri- and postoperative course data was recorded. The operating time (OT), the length of stay in hospital (LOS), the length of stay in the intensive care unit (ICU), the need for the administration of erythrocyte concentrates (ERY) and complications were recorded. Complications were classified into major and minor complications. Complications requiring surgical intervention were considered major complications. Major complications included anastomotic leaks (AI) and wound healing disorders (WHD). Minor complications included pneumonia (PM) and intestinal atonia (IA). In addition, the Clavien-Dindo score was recorded for all patients.
A special focus of this work was on the assessment and comparison of the quality of the surgical specimen. For this purpose, the number of lymph nodes, the distal resection margin and the circumferential resection margin were recorded and evaluated. The operations were performed by a total of three surgeons. Two of the surgeons had many years of experience in open colorectal oncological surgery. In addition, the surgeons were familiar with all common general laparoscopic procedures. The supervision of the implementation of laparoscopic oncologic procedures was monitored by a proven minimally invasive visceral surgeon, who had already performed more than 500 laparoscopic oncological colorectal resections before. The supervision was carried out as the assistance of the procedure with only temporary takeover of surgical steps. All cases were performed under supervision during the period of transformation.
The surgical standards of the procedures were performed according to the oncological guidelines at that time. This included central vessel ligation and adequate specimen length. Explicit CME procedures were not performed. Patients are positioned in supine position with both arms attached to the body using a vacuum mattress, regardless of the operation. Only sigmoid resection and deep anterior rectum resection were performed in lithotomy positioning. In addition, pneumatic calf compression cuffs were applied during each operation to minimize thrombotic or thromboembolic events. For right sided and central colon resections the specimen was recovered via a small supraumbilical median laparotomy. The anastomosis was usually created extracorporeally, side-to-side, isoperistaltic using a stapler. The auxiliary incision required for this is closed with a 4/0 serosubmucous suture. Only in the case of the left hemicolectomy is the anastomosis created end-to-end as a single-row hand suture and serosubmucous continuously with suture 4/0. The closure of the meso-slot was not performed.
For sigmoid and rectum resection the anastomosis was created using a trans anal circular stapler. To ensure a well-perfused anastomosis, the stapler anvil was only tied in if there was significant bleeding from the marginal arcade. The anastomosis was tested as an air-water test. In the case of anterior resections, a protective ileostomy is created in each case. If rectal extirpation was necessary, the specimen was retrieved transanally. A left-sided omental plasty was created for both anterior resections and rectal extirpation.
Statistics:
In order to analyze the collected data, SPSS Version 26 from IBM (SPSS Inc., Chicago, IL, USA) was used. Continuous parameters were descriptively characterized by the following information: Median (Mdn), Minimum (Min), Maximum (Max) and Percentage (%). Dichotomous variables were examined for their frequency distribution and their percentage. The chi-square test (χ^2) was used to determine statistical relationships. With a sample size N < 20 and an expected cell count < 5, Fisher's exact test was used. To compare defined endpoints at the rational scale level between two groups, the Mann-Whitney U test (MWU) was performed for unpaired samples. The above tests were two-tailed with a probability of error of p = 0.05. A statistically significant relationship was assumed with a p-value ≤ 0.05.