Retrospective analysis of surgical and oncological results of laparoscopic surgeries performed by residents of coloproctology

ABSTRACT Introduction: with the improvement and wide acceptance of laparoscopy in colorectal operations, there was a need for specific training of surgeons in training. There are few studies evaluating the postoperative results of laparoscopic colectomies performed by resident physicians and their impact on patient safety. Purpose: to analyze the surgical and oncological results of laparoscopic colectomies performed by coloproctology residents and compare them with data in the literature. Methods: this is a retrospective analysis of patients undergoing laparoscopic colorectal surgery performed by resident physicians at the Hospital das Clínicas de Ribeirão Preto, between 2014 and 2018. The clinical characteristics of the patients were studied, as well as the main surgical and oncological aspects in a period of one year. Results: we analyzed 191 operations, whose main surgical indication was adenocarcinoma, most of them stage III. The mean duration of surgeries was 210±58 minutes. There was a need for a stoma in 21.5% of the patients, mainly loop colostomy. The conversion rate was 23%, with 79.5% due to technical difficulties, and the main predictors of conversion were obesity and intraoperative accidents. The median length of stay was 6 days. Preoperative anemia was associated with a higher rate of complications (11.5%) and reoperations (12%). Surgical resection margins were compromised in 8.6% of cases. The one-year recurrence rate was 3.2% and the mortality rate was 6.3%. Conclusions: videolaparoscopic colorectal surgery performed by residents showed efficacy and safety similar to data found in the literature.


INTRODUCTION
L aparoscopic surgery for the treatment of colon and rectum diseases was introduced in the mid-1990s, driven by technological advances and the success of this approach in other gastrointestinal tract procedures 1,2 .
Among the advantages of laparoscopy, we highlight the lower endocrine-metabolic response to surgical trauma and, consequently, earlier recovery of digestive tract functions, with the possibility of rapid introduction and evolution of oral diet, thus reducing the length of hospital stay and allowing the patient to return to daily activities in a shorter time when compared with open surgery [3][4][5][6] .
Currently, laparoscopic surgery has good applicability in the elective surgical treatment of the main colorectal pathologies 7 .Among these, colorectal cancer is the most frequent, as it is the third most prevalent neoplasm in the world 8,9 .
With the advancement of minimally invasive colorectal surgery, adequate oncologic resection has become feasible also laparoscopically.When compared with the conventional technique, the safety and oncological results of this access route are equivalent [7][8][9][10] .
In addition to the numerous mentioned benefits, laparoscopy has become increasingly popular among colorectal surgeons and has gradually evolved to become the gold standard in the elective surgical treatment of colorectal pathologies 11 .In large centers, it is estimated that around 59% of colorectal surgeries are performed laparoscopically 12 .
Mota Retrospective analysis of surgical and oncological results of laparoscopic surgeries performed by residents of coloproctology learning curve from the surgeon.With the development and wide acceptance of laparoscopy for colon and rectal surgeries, the need for appropriate training arose for both staff surgeons and resident physicians 11 .Some authors tried to demonstrate the minimum number of surgeries for the colorectal surgeon to reach the apex of this learning curve, and it is possible to find in the literature the description of 10 to 200 necessary procedures [14][15][16] , but even today there is no consensus on this cutoff point.Nevertheless, more than just a number, the great discussion within the scope of medical education revolves around the best way to assess proficiency and define objective measures to calculate the real impact of the involvement of resident physicians in the procedures, mainly regarding the results in the short and long term 14,17 , since some studies have shown that the involvement of the training resident may be associated with a longer surgical time and a higher morbidity and mortality rate 7,18 .
We therefore propose a study with the aim of analyzing laparoscopic colorectal surgeries performed exclusively by resident physicians in a university hospital, evaluating the predictors of unsatisfactory results and comparing the surgical and oncological results with data from the literature.We included all patients submitted to laparoscopic surgery for colon and rectum diseases during the period.The oncological principles of resection, such as ligation of the mesenteric vessels at the root and corresponding lymphadenectomies, were applied in all procedures, including the cases of benign disease.We excluded patients who underwent laparoscopy in which the surgery was converted before the main surgical time due to technical difficulties, or in which the attending physician needed to take control of the surgery during the main surgical time.

METHODS
Patients diagnosed with colorectal neoplasia were staged according to the service's standard protocol, with colonoscopy with biopsy and CT scans of the chest, abdomen, and pelvis.
From the medical records we collected data on the independent variables identification, registration, race, sex, age, BMI, habits, ASA anesthetic risk classification, preoperative hemoglobin, albumin and total protein levels, tumor marker level (CEA), primary site neoplasm, and disease clinical staging.
We also gathered data on the outcomes duration of surgery, intraoperative accidents, need for stoma construction, postoperative surgical complications, length of stay, early reoperation rate (up to 30 days after the procedure), rate of complete resection of the lesion, late surgical complications, and mortality.

RESULTS
In the analyzed period, 191 laparoscopic intestinal surgeries were performed.The main clinical characteristics of the patients are detailed in Table 1.
The treatment of colorectal cancer (CRC) was the main surgical indication (n=151/79.1%).Table 2 summarizes the main oncological characteristics of the sample.

Retrospective analysis of surgical and oncological results of laparoscopic surgeries performed by residents of coloproctology
The early mortality rate was 2.1% (n=4).
The presence of early complications and the need for reoperation were factors associated with early mortality (Table 5).
The mortality rate within one year of surgery was 4.2% (n=8).In univariate and multivariate analyses, we observed that early complications and diagnosis of malignant neoplasm with invasion of adjacent organs were predictors of late mortality (Table 6).

DISCUSSION
Currently, laparoscopy is the preferred access route to the abdominal cavity in elective operations for the treatment of benign or malignant colorectal diseases, due to its numerous benefits.Despite the advantages and dissemination of the technique in clinical practice, until the present study, little was known about the performance of training physicians, particularly in our country.suggested that high BMI would be an independent factor for conversion and intraoperative complications.
In the present study, laparoscopic colorectal surgery was performed in more than 60% of the patients, without complications or need for conversion to the open approach.Even so, the conversion rate in obese individuals was higher, in agreement with the literature 21 .To reduce this percentage, Parker, Homma, and Miskovic suggested selecting the cases that should be operated on during the learning process [21][22][23] .
The immediate identification of an accident still during the performance of a surgical procedure reduces the chances of postoperative complications, which could become more serious if identified late.Intraoperative accidents end up indicating the conversion of surgery to the open approach, especially during the learning curve, when the resident physician still does not have sufficient skills to solve complications by laparoscopic approach.In this study, there was conversion in 75% of the cases in which accidents were identified during the intraoperative period, with immediate resolution during the same surgical time.We analyzed several factors to assess whether there was an association with an increase in the incidence of accidents, but none was statistically significant.The main accidents described in this study were vascular, bladder, and ureteral injuries.
Most published papers mention similar accidents 24 .
Kirchhoff et al. found a rate of intraoperative complications of 7.4%, reporting, in addition to bleeding and urinary tract injuries, intestinal injuries and problems with making the anastomosis, as well as 13% of anesthetic complications.Unlike what we found in the present statistical data (absence of direct association between risk factors and occurrence of accidents), this group described that advanced age, comorbidities, male sex, and diagnosis of neoplasia would be predictive factors for the occurrence of intraoperative accidents 25 .
The success of an anastomosis is related, among other factors, to good vascularization and absence of tension, in addition to the surgeon's degree of experience.When one of the factors is compromised, the possibility of making a protective stoma is considered, with early closure programmed,

Mota
Retrospective analysis of surgical and oncological results of laparoscopic surgeries performed by residents of coloproctology assistant surgeon reported that the length of stay between the two groups was similar 29 .Gongun et al., in turn, reported that, though the hospitalization time of the patients submitted to laparoscopic colorectal surgery by the group of residents was slightly longer than in the control group, this difference could increase the hospital costs of treating such patients, causing an important financial impact, and a cost-benefit analysis should be made 30 .
The analysis of mortality in this population undergoing laparoscopic colorectal surgery performed by resident physicians is essential to define the safety of this procedures for the patient.The main factors associated with early mortality (within 30 days after surgery) were the presence of postoperative complications and the need for early reoperation, present in the clinical evolution of all patients who died, and the rate found was 2.1%, similar to that reported by the national multicenter study published by Campos et al., up to 3.2%, and to the studies cited in a Brazilian study (0.7 to 2.1%) 31 .
We carried out a retrospective follow-up of the patients in this study for a period of one year, showing a late mortality rate of 4.2%.Statistically, the factors that were associated with this poor prognosis were the presence of postoperative complications and advanced staging of colorectal cancer at diagnosis.We recorded no deaths between 30 days and one year after surgery among patients with stages I and II, only in patients with stages III and IV.The late mortality rate in this group was much higher than the reported in the literature, almost 31%, compared with 2% in the group of patients with earlier disease.The degree of tumor invasion ("T" staging) was an important predictor of late mortality, showing an increased risk in the group of patients with locally advanced disease, with invasion of adjacent organs, in agreement with the article by Shootman 32 .

CONCLUSION
Performing laparoscopy in a university environment was technically safe, with acceptable complications rates and without a significant increase in patient morbidity and mortality, similar to data in the literature.necessary in 21.5% of the patients in the sample.Other authors have found similar rates, with protective loop ileostomy generally preferred by several authors 26 .In our institution, however, loop colostomy is the most used option.
We defined early complications as those occurring up to 30 days after surgery.Such complications occurred in 11.5% of the patients, the main one being anastomotic dehiscence.In addition to this complication, other authors mentioned surgical site infection and late bleeding, and reported that preoperative anemia had a significant influence on intraoperative complications, but with little influence on postoperative morbidity 27 .
In the present study, however, preoperative anemia was the only statistically significant factor associated with early postoperative complications, present in 2/3 of patients who evolved with complications within 30 days after the procedure.Other factors evaluated were hypoalbuminemia and previous radiotherapy, but the statistical analysis did not show a direct association between these factors and the increase in postoperative complications.
All patients who had early complications were reapproached, including the eight patients who evolved with anastomotic dehiscence, which is the main indication for surgical revision.In all, 12% of patients underwent a new surgical procedure within one month of the initial surgery.In addition to the patients who evolved with the early complications described, one patient with an intraoperatively unidentified ureteral lesion was reoperated, and evolved with a urinary fistula, and another patient who evolved with clinical worsening requiring a cavity second look.Preoperative anemia was also the main factor associated with early reoperations.
The other factors analyzed did not show statistical significance.
Regarding length of stay, we found that, on average, patients needed to remain in the hospital environment for about six days, shorter than the averages described in the literature, and close to the statistics of surgeons with good experience in laparoscopy.Del Rei et al. recorded a longer hospital stay, around nine days 28 .
Kirshhoff et al. reported an average time of 10.5 days 25 .
Most studies that compared the results of surgeries performed by the training surgeon and the

R E S U M O R E S U M O
This is a retrospective study that analyzed the medical records of patients who underwent laparoscopic colectomies between January 2014 and December 2018, carried out after approval by the Ethics in Research Committee of the Hospital das Clínicas, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo (HC-FMRP-USP).We assessed operations in which resident physicians of the last years, R4 and R3, acted as first surgeon and assistant, respectively, under the supervision of two assistant physicians of the Coloproctology Division of HC-FMRP-USP.All residents underwent basic laparoscopic training in their first years of residency in general surgery.
We entered and organized the collected data in a database on the Microsoft Access software and analyzed them with the SPSS (Statistical Package for the Social Sciences) software version 21.0.We evaluated the variables' distribution with the Kruskal-Wallis test.For sample characterization and descriptive analysis, we used frequency measures (absolute count and percentage), measures of central tendency (mean or median), and measures of dispersion (standard deviation or interquartile range).

Table 1 -
Clinical characteristics of operated patients.
1 SD: standard deviation; 2 Surgical risk classification by the American Society of Anesthesiologists.

Table 2 -
Oncological characteristics of patients diagnosed with CRC undergoing laparoscopic surgery.

Table 3 -
Main surgical results of patients submitted to laparoscopy.
univariate and multivariate analyses, we observed that obesity, diagnosis of malignant neoplasm with invasion of adjacent organs, and intraoperative accidents were predictive factors for conversion to laparotomy (Table4).patients.All patients with early complications underwent surgical intervention.One patient underwent revision of the cavity, with no findings, and another underwent surgical reapproach to correct a ureter injury.Anemia was associated with a higher rate of early reoperations.

Table 4 -
Multivariate analysis of risk factors for conversion from laparoscopic to open access route.

Table 5 -
Multivariate analysis of factors associated with early mortality.

Table 6 -
Multivariate analysis of factors associated with late mortality.
15isher's exact test; OR: odds ratio; 95% CI: 95% confidence interval;2Recommended by the Union for International Cancer Control (UICC).formation of the learning curve of colorectal surgeons when compared with series of published cases, which suggest that performing 40 or more surgeries of the colon and rectum by laparoscopy guarantees skill and comfort for training physicians15.Some studies, however, Regarding the duration of the procedures, the average intraoperative time was longer than that described by most published studies, especially those that compared the performance of resident physicians with that of assistants in colorectal laparoscopicRev Col Bras Cir 50:e20233404In more than half of obese patients, laparoscopic colorectal surgery was feasible, without conversion or complications.However, a conversion rate above 35% in the sample of obese patients is high and needs to be taken into account, since 55.1% of patients undergoing colorectal laparoscopic surgery were classified as overweight or obese.Homma et al.