Does Robot Overcome Obesity-related Limitations of Minimally Invasive Rectal Surgery for Cancer?

Comparison of robotic versus laparoscopic surgery for visceral obesity in mid-low rectal cancer: a propensity-matched analysis

Obesity is becoming more and more common, and measuring visceral fat area (VFA) is a useful diagnostic technique for visceral obesity (VO). The purpose of this research is to compare the surgical results of robotic versus laparoscopic rectal surgery, with a focus on assessing the benefits of the latter method for treating both VO and mid-low rectal cancer. Patients receiving laparoscopic or robotic anterior rectal excision at Northern Jiangsu People's Hospital's general surgery department were included in the retrospective analysis. 242 people in all took part in the study; 121 cases were assigned to the robotic surgery (RS) group and another 121 cases to the laparoscopic surgery (LS) group. In comparison to LS, our results show that RS led to a shorter period for the recovery of bowel function (p = 0.03), a shorter hospital stay (p < 0.001), a smaller intraoperative blood loss (p < 0.001), and a shorter time until the commencement of oral intake (p = 0.041). However, there were no statistically significant differences between the two groups in terms of the indices of histopathologic specimens, the proportion of temporary loop ileostomy, and the incidence of early postoperative problems (p > 0.05). When patients with VO undergo surgery for rectal cancer, RS has the added benefit of accelerating patient recovery while producing results that are similar to LS in the near run.

Outcomes of robot-assisted versus laparoscopic surgery for colorectal cancer in morbidly obese patients: A propensity score-matched analysis of the US Nationwide Inpatient Sample

BACKGROUND AND AIM

Morbid obesity is associated with poorer postoperative outcomes in colorectal cancer (CRC) patients. We aimed to evaluate short-term outcomes after robotic versus conventional laparoscopic CRC resection in morbidly obese patients.

METHODS

This population-based, retrospective study extracted data from the US Nationwide Inpatient Sample during 2005-2018. Adults ≥ 20 years old, with morbid obesity and CRC, and undergoing robotic or laparoscopic resections were identified. Propensity score matching (PSM) was applied to minimize the confounding. Univariate and multivariable regression was conducted to evaluate the associations between outcomes and study variables.

RESULTS

After PSM, 1296 patients remained. The risks of any postoperative complication (adjusted odds ratio [aOR] = 0.99, 95% confidence interval [CI]: 0.80, 1.22), prolonged length of stay (LOS) (aOR = 0.80, 95% CI: 0.63, 1.01), death (aOR = 0.57, 95% CI: 0.11, 3.10), or pneumonia (aOR = 1.13, 95% CI: 0.73, 1.77) were not significantly different between the two procedures after adjustment. Robotic surgery was significantly associated with greater hospital cost (aBeta = 26.26, 95% CI: 16.08, 36.45) than laparoscopic surgery. Stratified analyses revealed that, in patients with tumor located at the colon, robotic surgery was associated with lower risk of prolonged LOS (aOR = 0.72, 95% CI: 0.54, 0.95).

CONCLUSIONS

In patients with morbid obesity, risks of postoperative complication, death, or pneumonia are not significantly different between robotic and laparoscopic CRC resection. Among patients with tumor located at the colon, robotic surgery is associated with lower risk of prolonged LOS. These findings fill the knowledge gap and provide useful information for clinicians on risk stratification and treatment choice.

Impact of obesity on patients undergoing surgery for rectal cancer in Australia and New Zealand

PURPOSE

Patients with obesity undergoing rectal cancer surgery may have an increased risk of developing complications, though evidence is inconclusive. The aim of this study was to determine the direct impact of obesity on postoperative outcomes using data from a large clinical registry.

METHOD

The Binational Colorectal Cancer Audit registry was used to identify patients who underwent rectal cancer surgery in Australia and New Zealand from 2007-2021. Primary outcomes were inpatient surgical and medical complications. Logistic regression models were developed to describe the association between body-mass index (BMI) and outcomes.

RESULTS

Among 3,708 patients (median age 66 years [IQR 56.75-75], 65.0% male), 2.0% had a BMI < 18.5 kg/m2, 35.4% had a BMI of 18.5-24.9 kg/m2, 37.6% had a BMI of 25.0-29.9 kg/m2, 16.7% had a BMI of 30.0-34.9 kg/m2, and 8.2% had a BMI ≥ 35.0 kg/m2. Surgical complications occurred in 27.7% of patients with a BMI of 18.5-24.9 kg/m2, 26.6% of patients with a BMI of 25.0-29.9 kg/m2 (OR 0.91, 95% CI 0.76-1.10), 28.5% with a BMI of 30.0-34.9 kg/m2 (OR 0.96, 95% CI 0.76-1.21), and 33.2% with a BMI ≥ 35.0 kg/m2 (OR 1.27, 95% CI 0.94-1.71). Modelling BMI as a continuous variable confirmed a J-shaped relationship. The association between BMI and medical complications was more linear.

CONCLUSION

Risk of postoperative complications is increased in patients with obesity undergoing rectal cancer surgery.

Relationship between body mass index and short-term postoperative prognosis in patients undergoing colorectal cancer surgery

BACKGROUND

Obesity is a state in which excess heat is converted into excess fat, which accumulates in the body and may cause damage to multiple organs of the circulatory, endocrine, and digestive systems. Studies have shown that the accumulation of abdominal fat and mesenteric fat hypertrophy in patients with obesity makes laparoscopic surgery highly difficult, which is not conducive to operation and affects patient prognosis. However, there is still controversy regarding these conclusions.

AIM

To explore the relationship between body mass index (BMI) and short-term prognosis after surgery for colorectal cancer.

METHODS

PubMed, Embase, Ovid, Web of Science, CNKI, and China Biology Medicine Disc databases were searched to obtain relevant articles on this topic. After the articles were screened according to the inclusion and exclusion criteria and the risk of literature bias was assessed using the Newcastle-Ottawa Scale, the prognostic indicators were combined and analyzed.

RESULTS

A total of 16 articles were included for quantitative analysis, and 15588 patients undergoing colorectal cancer surgery were included in the study, including 3775 patients with obesity and 11813 patients without obesity. Among them, 12 articles used BMI ≥ 30 kg/m² and 4 articles used BMI ≥ 25 kg/m² for the definition of obesity. Four patients underwent robotic colorectal surgery, whereas 12 underwent conventional laparoscopic colorectal resection. The quality of the literature was good. Meta-combined analysis showed that the overall complication rate of patients with obesity after surgery was higher than that of patients without obesity [OR = 1.35, 95%CI: 1.23-1.48, Z = 6.25, P < 0.0001]. The incidence of anastomotic leak after surgery in patients with obesity was not significantly different from that in patients without obesity [OR = 0.99, 95%CI: 0.70-1.41), Z = -0.06, P = 0.956]. The incidence of surgical site infection (SSI) after surgery in patients with obesity was higher than that in patients without obesity [OR = 1.43, 95%CI: 1.16-1.78, Z = 3.31, P < 0.001]. The incidence of reoperation in patients with obesity after surgery was higher than that in patients without obesity; however, the difference was not statistically significant [OR = 1.15, 95%CI: 0.92-1.45, Z = 1.23, P = 0.23]; Patients with obesity had lower mortality after surgery than patients without obesity; however, the difference was not statistically significant [OR = 0.61, 95%CI: 0.35-1.06, Z = -1.75, P = 0.08]. Subgroup analysis revealed that the geographical location of the institute was one of the sources of heterogeneity. Robot-assisted surgery was not significantly different from traditional laparoscopic resection in terms of the incidence of complications.

CONCLUSION

Obesity increases the overall complication and SSI rates of patients undergoing colorectal cancer surgery but has no influence on the incidence of anastomotic leak, reoperation rate, and short-term mortality rate.

Assessing the role of robotic proctectomy in obese patients: a contemporary NSQIP analysis

Robotic proctectomy has become increasingly popular for both benign and malignant indications. The purpose of this study was to determine if the robotic approach has a distinct advantage over laparoscopy in obese patients, which has been suggested by previous subgroup analyses. We performed a retrospective review of 2016–2018 National Surgery Quality Improvement Program (NSQIP) data to compare outcomes between patients who underwent robotic versus laparoscopic proctectomy, stratified by Body Mass Index (BMI) subgroups. We also compared outcomes of converted minimally invasive proctectomy to planned open operations. Four thousand four hundred eighteen (69.3%) patients underwent laparoscopic proctectomy, and 1956 (30.7%) patients underwent robotic proctectomy. Robotic proctectomy was associated with a significantly lower conversion rate compared to laparoscopic proctectomy (5.1% vs 12.3%; p = 0.002), and this relationship was maintained on an adjusted model. Obese (BMI > 30) patients were more likely to require conversion in both laparoscopic and robotic groups with the greatest difference in the conversion rate in the obese subgroup. Patients who underwent conversion had higher composite morbidity compared to patients who underwent planned open operations (50.8% vs 41.3%; p < 0.001). And among patients with rectal cancer, robotic proctectomy was associated with a greater incidence of positive radial tumor margins compared to laparoscopic proctectomy (8.0% vs 6.4%; p = 0.039), driven primarily by the obese subgroup. Our study demonstrates that robotic proctectomy is associated with a 7% lower conversion rate compared to laparoscopy and that obese patients are more likely to require conversion than non-obese patients. Among obese patients with rectal cancer, we identified an increased risk of positive radial margins with robotic compared to laparoscopic proctectomy.

Impact of body-mass index on treatment and outcome in locally advanced rectal cancer: A secondary, post-hoc analysis of the CAO/ARO/AIO-04 randomized phase III trial

BACKGROUND

A better understanding of the impact of body-mass index (BMI) on the course of multimodal therapy and oncologic outcome in locally advanced rectal cancer could provide new insights for optimization of treatment and supportive strategies.

PATIENTS AND METHODS

Correlations of BMI with pretreatment clinical, surgical, and pathological characteristics, toxicity and treatment adherence using the Pearson's Chi-squared test or logistic regression were analyzed in the CAO/ARO/AIO-04 III trial cohort (n = 1236). One-way ANOVA or Welch test were used to analyze correlations of baseline blood-parameters and BMI. The prognostic role of BMI was examined with log-rank test and multivariate cox regression.

RESULTS

Obese had a better ECOG performance status (P = 0.027) but were less likely to undergo sphincter preserving surgery (P = 0.01). Post-surgical complications did not differ significantly between BMI classes, whereas underweight was associated with increased neutrophil (P = 0.025) and platelet counts (P < 0.001), poorer TME quality (P = 0.007) and increased incidence of acute organ toxicity (P < 0.001). After a median follow-up of 50 months, underweight [HR 1.896, P = 0.014] and overweight [HR 1.392, P = 0.042] were associated with worse DFS. Obese patients had an increased risk of death [HR 1.653, P = 0.032]. Normalweight men showed superior OS compared to underweight [HR 4.070, P = 0.002], overweight [HR 2.077, P = 0.010], severe overweight [HR 1.886, P = 0.026] and obese [HR 2.046, P = 0.015] men. Adding oxaliplatin to standard CRT significantly improved DFS in obese patients (P = 0.034).

CONCLUSION

In our study, underweight and overweight correlated with inferior DFS, underweight experienced more organ toxicity and obesity was associated with an increased risk of abdominoperineal resection and poorer overall survival.

Obese patients and robotic colorectal surgery: systematic review and meta-analysis

BACKGROUND

Obesity is a major health problem, demonstrated to double the risk of colorectal cancer. The benefits of robotic colorectal surgery in obese patients remain largely unknown. This meta-analysis evaluated the clinical and pathological outcomes of robotic colorectal surgery in obese and non-obese patients.

METHODS

MEDLINE, Embase, Global Health, Healthcare Management Information Consortium (HMIC) and Midwives Information and Resources Service (MIDIRS) databases were searched on 1 August 2018 with no language restriction. Meta-analysis was performed according to PRISMA guidelines. Obese patients (BMI 30 kg/m2 or above) undergoing robotic colorectal cancer resections were compared with non-obese patients. Included outcome measures were: operative outcomes (duration of surgery, conversion to laparotomy, blood loss), postoperative complications, hospital length of stay and pathological outcomes (number of retrieved lymph nodes, positive circumferential resection margins and length of distal margin in rectal surgery).

RESULTS

A total of 131 full-text articles were reviewed, of which 12 met the inclusion criteria and were included in the final analysis. There were 3166 non-obese and 1420 obese patients. A longer duration of surgery was documented in obese compared with non-obese patients (weighted mean difference -21·99 (95 per cent c.i. -31·52 to -12·46) min; P < 0·001). Obese patients had a higher rate of conversion to laparotomy than non-obese patients (odds ratio 1·99, 95 per cent c.i. 1·54 to 2·56; P < 0·001). Blood loss, postoperative complications, length of hospital stay and pathological outcomes were not significantly different in obese and non-obese patients.

CONCLUSION

Robotic surgery in obese patients results in a significantly longer duration of surgery and higher conversion rates than in non-obese patients. Further studies should focus on better stratification of the obese population with colorectal disease as candidates for robotic procedures.

Mesorectal fat area and mesorectal area affect the surgical difficulty of robotic-assisted mesorectal excision and intersphincteric resection respectively in different ways

AIM

Many studies have demonstrated predictors of the difficulty of laparoscopic anterior resection for rectal cancer. Few studies focus on the influence of pelvic dimensions on robotic-assisted mesorectal excision (ME) and intersphincteric resection (ISR). This study aimed to evaluate the influences of the mesorectal fat area (MFA) and mesorectal area on the difficulty of robotic sphincter-saving surgery.

METHODS

We included 156 patients with middle and low rectal cancer who underwent robotic sphincter-saving surgery. Clinical and anatomical factors, including the pelvic dimensions, were collected. Linear regression was performed for variables associated with surgical duration. We also performed subgroup analyses for robotic-assisted ME and ISR. Logistic regression was used to find variables associated with transanal dissection.

RESULTS

For patients with middle or low rectal cancer, the sacral length and tumour distance from the anal verge were independently associated with surgical duration. The pT stage, sacral length and the MFA were independent predictors for the surgical duration of robotic-assisted ME. By contrast, a small mesorectal area was independently related to a longer duration of robotic-assisted ISR. The pelvic outlet length was independently associated with the use of transanal dissection for ISR.

CONCLUSION

It is suggested that a large MFA could affect the difficulty of ME in robotic-assisted ME, while a small mesorectal area could increase the surgical difficulty of robotic-assisted ISR for low rectal cancer. Besides, the pelvic outlet length was associated with the use of transanal dissection. Further studies are needed to validate the results and draw more scientific conclusions.

Laparoscopic Mesorectal Excision in Obesity: Novel Insights and Technical Strategies

INTRODUCTION

Obesity is a burgeoning problem worldwide. Although beneficial in obese patients, conventional laparoscopic mesorectal excision for rectal cancer is technically challenging, with a higher conversion rate to open compared with nonobese patients. We describe novel strategies to circumvent these difficulties.

TECHNIQUE

The key steps are 1) lateral-to-medial colonic mobilization and left-sided mesorectal excision with the surgeon on the patient's right; 2) switching to the patient's left for right-sided mesorectal excision; 3) further rectal retraction with cotton tape and preperitoneal fat sling; and 4) caudal-to-cephalad mobilization of colon after distal transection, which facilitates extrapelvic mesenteric dissection and vessel ligation.

RESULTS

These techniques optimize gravity to negate the lack of exposure due to visceral obesity. Triangulation is improved by changing the surgeon's position during mesorectal dissection. This allows accurate identification of anatomical planes and avoids excessive pneumoperitoneum pressures and Trendelenburg tilt.

CONCLUSIONS

Adopting these strategies can facilitate laparoscopic mesorectal excision in the obese patient and may reduce conversion to open.

Robotic-assisted surgery for rectal cancer: Current state and future perspective

Interest in minimally invasive surgery has increased in recent decades. Robotic-assisted laparoscopic surgery (RALS) was introduced as the latest advance in minimally invasive surgery. RALS has the potential to provide better clinical outcomes in rectal cancer surgery, allowing for precise dissection in the narrow pelvic space. In addition, RALS represents an important advancement in surgical education with respect to use of the dual-console robotic surgery system. Because the public health insurance systems in Japan have covered the cost of RALS for rectal cancer since April 2018, RALS has been attracting increasingly more attention. Although no overall robust evidence has yet shown that RALS is superior to laparoscopic or open surgery, the current evidence supports the notion that technically demanding subgroups (patients with obesity, male patients, and patients treated by extended procedures) may benefit from RALS. Technological innovation is a constantly evolving field. Several companies have been developing new robotic systems that incorporate new technology. This competition among companies in the development of such systems is anticipated to lead to further improvements in patient outcomes as well as drive down the cost of RALS, which is one main concern of this new technique.