Laparoscopic colorectal surgery: why, when, how?

Robotic colorectal surgery in Latin America: a systematic review on surgical outcomes

Background and objectives

Robotic approach in colorectal surgery is rapidly gaining interest, particularly in the context of rectal cancer resection. Despite economic barriers, substantial proliferation of robotic colorectal procedures has been observed throughout Latin America. However, there is a lack of data regarding intraoperative and early postoperative outcomes, as well as oncological and long-term results. This systematic review aims to provide an overview of the surgical outcomes of robotic-assisted colorectal approaches across Latin America.

Material and methods

A systematic literature search of electronic databases, including PubMed, LILACS, Scopus, Cochrane Library and Scielo, was performed and reported in line with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The main target of the literature search was studies that reported outcomes of colorectal robotic surgery in Latin America.

Results

A total of 9,694 published articles were identified from the initial search. Nine thousand six hundred thirty-six publications were excluded after title and abstract review and removal of duplicates. Fifty-eight articles were thoroughly reviewed, and 11 studies met the inclusion criteria. The critical appraisal of study quality (biases risk assessment) was performed according to the Joanna Briggs Institute (JBI) Manual for Evidence Synthesis. In general, the overall study quality was poor. Of the 11 studies included in the analysis, ten addressed intraoperative and early postoperative outcomes, seven addressed oncological/pathological outcomes, and just one addressed long-term outcomes. Ten studies evaluated intraoperative and early postoperative outcomes, encompassing a total of 425 patients, the majority of whom were diagnosed with colorectal cancer. Morbidity rates exhibited a range between 0% and 45.9%, while mortality ranged from 0% to 2.5%.

Conclusion

Few studies have been published addressing intraoperative, postoperative, pathological, and oncological outcomes of robotic colorectal surgery in this region. Undoubtedly, there are unique challenges not encountered by developed countries, including economic obstacles in establishing structured training programmes and high-quality centres for the development of robotic surgery. Further studies are needed to assess the real extent of robotic surgery in the region and its results.

Systematic Review Registration

https://www.crd.york.ac.uk/, PROSPERO (CRD42023494112).

L-Arginine/NO Pathway Metabolites in Colorectal Cancer: Relevance as Disease Biomarkers and Predictors of Adverse Clinical Outcomes Following Surgery

The L-Arginine/NO pathway is involved in carcinogenesis and immunity. Its diagnostic and prognostic value in colorectal cancer (CRC) was determined using tandem mass spectrometry in 199 individuals (137 with CRC) and, during a three-day follow up, in 60 patients undergoing colorectal surgery. Citrulline was decreased and asymmetric (ADMA) and symmetric (SDMA) dimethylarginines and dimethylamine (DMA) were increased in CRC. The DMA increase corresponded with CRC advancement while arginine, ADMA, and SDMA levels were higher in left-sided cancers. Arginine, citrulline, ADMA, and DMA dropped and SDMA increased post incision. Females experienced a more substantial drop in arginine. The arginine and ADMA dynamics depended on blood loss. The initial SDMA increase was higher in patients requiring transfusions. Postoperative dynamics in arginine and dimethylarginines differed in robot-assisted and open surgery. Concomitant SDMA, citrulline, and DMA quantification displayed a 92% accuracy in detecting CRC. Monitoring changes in arginine, ADMA, and SDMA in the early postoperative period predicted postoperative ileus with 84% and surgical site infections with 90% accuracy. Changes in ADMA predicted operative morbidity with 90% and anastomotic leakage with 77% accuracy. If positively validated, L-arginine/NO pathway metabolites may facilitate CRC screening and surveillance, support differential diagnosis, and assist in clinical decision-making regarding patients recovering from colorectal surgery.

Automated endoscopic detection and classification of colorectal polyps using convolutional neural networks

BACKGROUND

Recently the American Society for Gastrointestinal Endoscopy addressed the 'resect and discard' strategy, determining that accurate in vivo differentiation of colorectal polyps (CP) is necessary. Previous studies have suggested a promising application of artificial intelligence (AI), using deep learning in object recognition. Therefore, we aimed to construct an AI system that can accurately detect and classify CP using stored still images during colonoscopy.

METHODS

We used a deep convolutional neural network (CNN) architecture called Single Shot MultiBox Detector. We trained the CNN using 16,418 images from 4752 CPs and 4013 images of normal colorectums, and subsequently validated the performance of the trained CNN in 7077 colonoscopy images, including 1172 CP images from 309 various types of CP. Diagnostic speed and yields for the detection and classification of CP were evaluated as a measure of performance of the trained CNN.

RESULTS

The processing time of the CNN was 20 ms per frame. The trained CNN detected 1246 CP with a sensitivity of 92% and a positive predictive value (PPV) of 86%. The sensitivity and PPV were 90% and 83%, respectively, for the white light images, and 97% and 98% for the narrow band images. Among the correctly detected polyps, 83% of the CP were accurately classified through images. Furthermore, 97% of adenomas were precisely identified under the white light imaging.

CONCLUSIONS

Our CNN showed promise in being able to detect and classify CP through endoscopic images, highlighting its high potential for future application as an AI-based CP diagnosis support system for colonoscopy.

Impact of radiofrequency energy on intraoperative outcomes of laparoscopic colectomy for cancer in obese patients

Nowadays laparoscopic approach is accepted as a valid alternative to open surgery for the treatment of colorectal cancer. Several studies consider this approach to be safe and feasible also in obese patients, even if dissection in these patients may require a longer operative time and involve higher blood loss. To facilitate laparoscopic approach, more difficult in these patients, several energy sources for laparoscopic dissection and sealing, has been adopted recently. The aim of this study is to investigate the possible intraoperative advantages of radiofrequency energy in terms of blood loss and operative time in obese patients undergoing laparoscopic resection for cancer. All patients who underwent laparoscopic surgery for colorectal cancer from January 2010 to December 2015 were registered in a prospective database. Patients with a body mass index BMI (kg/m2) ≥30 were defined as obese, and patients with a BMI (kg/m2) <30 were defined as non-obese. All 136 obese patients observed were divided retrospectively into 2 groups according to the devices used for dissection: 83 patients (Historical group: B) on whom dissection and coagulation were performed using other energy sources (monopolar electrocautery scissors, bipolar electrical energy, ultrasonic coagulating shears) and 53 patients who were treated with electrothermal bipolar vessel sealing (Caiman group: A). In group A, the Laparoscopic Caiman 5 (Aesculap AG, Tuttlingen, Germany) was the only instrument employed in the whole procedure. The study examined only three types of operation: right colectomy (RC), left colectomy (LC), and anterior resection (AR). Preoperative data were similar for RC, LC, and AR in both groups (A and B). The mean operative time was statistically shorter in the Caiman group than in the Historical group [104 vs 124 min (p 0.004), 116 vs 140 min (p 0.004), and 125 vs 151 min (p 0.003) for RC, LC, and AR between group A and B, respectively]. Also intraoperative blood loss results significantly lower in the Caiman group than in the historical one [52 ml vs 93 for RC (p 0.003); 65 vs 120 ml for LC (p 0.001); 93 vs 145 ml for AR (p 0.002) between group A and B, respectively]. No intraoperative complications were recorded in either group. The mean conversion rate was 4.4% (6 patients). There were no statistical differences in intensive care unit (ICU) stay, functional outcomes, mean hospital stay and overall morbidity rate between the two groups. There was no mortality in either group. The use of the Caiman EBVS instrument shows significant advantages with respect to a small number of intraoperative parameters. We can conclude that use of this radiofrequency device, in the laparoscopic approach, offers advantages in terms of lower intraoperative blood loss and shorter operative time in obese patients with colorectal cancer.

Dexmedetomidine improves gastrointestinal motility after laparoscopic resection of colorectal cancer: A randomized clinical trial

BACKGROUND

To investigate the effects of intraoperative application of dexmedetomidine (Dex) on early gastrointestinal motility after laparoscopic resection of colorectal cancer.

METHODS

In this prospective, randomized double-blind investigation, 60 patients who underwent laparoscopic resection of colorectal cancer were randomly allocated to receive Dex (DEX group, n = 30) or saline (CON group, n = 30). In the DEX group, Dex was loaded (1 μg/kg) before anesthesia induction and was infused (0.3 μg/kg/h) during surgery. Time to postoperative first flatus (FFL) and first feces (FFE), and time to regular diet were recorded. Serum diamine oxidase (DAO) activity and intestinal fatty acid-binding protein (I-FABP) were detected.

RESULTS

Both the time to the FFL (44.41 ± 4.51 hours vs 61.03 ± 5.16 hours, P = 0.02) and the time to the FFE (60.67 ± 4.94 hours vs 82.50 ± 6.88 hours, P = 0.014) were significantly shorter in the DEX group than the CON group. Furthermore, the time to regular diet of the DEX group was shorter than that of the CON group (76.15 ± 4.11 hours vs 91.50 ± 5.70 hours, P = 0.037). Both DAO and I-FABP increased significantly from beginning of surgery to postoperative day 1 in the CON group (2.49 ± 0.41 ng/mL vs 4.48 ± 0.94 ng/mL for DAO, P = 0.028, 1.32 ± 0.09 ng/mL vs 2.17 ± 0.12 ng/mL for I-FABP, P = 0.045, respectively), whereas no significant change was observed in the DEX group. Furthermore, patients in the DEX group had stable hemodynamics and shorter hospital stay than those in the CON group.

CONCLUSION

Dex administration intraoperatively benefits recovery of gastrointestinal motility function after laparoscopic resection of colorectal cancer with stable hemodynamics during surgery though further studies are needed to explore the mechanisms of Dex on gastrointestinal motility.