Effect of local ozone treatment on rats with anterior rectal resection and the possible mechanisms

BACKGROUND

Anterior resection syndrome (ARS) is characterized by the diverse and interchangeable evacuatory symptoms that may occur following distal colorectal resection. We aimed to investigate the effect and potential mechanisms of ozone perfusion on rats with anterior rectal resection (ARR).

MATERIAL AND METHODS

After establishment of rat ARR model, 20, 40 and 80 ug/ml ozone was used to treat rats by enema administration. The pathological examination of intestinal tissue was detected using hematoxylin-eosin staining. The rate of loose stools, minimum threshold volume of abdominal withdrawal reflex (AWR) and Bristol grade were used to evaluate the degree of abnormal defecation function. Subsequently, the levels of oxidative stress- and inflammation-related markers, 5-hydroxytryptamine (5-HT), inducible nitric oxide synthase (iNOS) and nitric oxide (NO) in the serum and intestinal tissue were determined with the corresponding kits. Meanwhile, the expression of nuclear factor kappa B (NF-κB) p65, transient receptor potential vanilloid (TRPV)1, TRPV4, iNOS and 5-HT receptor 3A (5-HTR3A) was determined with RT-qPCR and western blotting.

RESULTS

Ozone administration (20 and 40 ug/ml) significantly alleviated the pathological changes of intestinal tissue-induced by ARR, accompanied by the decreased loose stools rate, Bristol score and increased abdominal withdraw reflex. However, 80 ug/ml of ozone intervention played opposite roles in the aforementioned changes with 20 and 40 ug/ml of ozone. Additionally, remarkably elevated reactive oxygen species (ROS), malonaldehyde (MDA), superoxide dismutase (SOD), 5-HT, iNOS and NO levels were observed in the ozone-treated groups (20 and 40 ug/ml), while high dose of ozone drastically improved ROS, MDA, 5-HT, iNOS and NO levels but reduced the activity of SOD. Consistently, the contents of inflammatory factors were decreased after low and middle doses of ozone administration. However, high dose of ozone aggravated the inflammatory injury. Moreover, 20 and 40 ug/ml ozone upregulated TRPV1 and TRPV4 expression but downregulated 5-HTR3A expression, which was restored after 80 ug/ml of ozone intervention. Remarkably, the levels of NF-κB p65 and iNOS were dose-dependently enhanced following ozone treatment.

CONCLUSIONS

Taken together, low concentration of ozone attenuated intestinal injury induced by ARR via balancing oxidative stress and inflammation, but high concentration of ozone exacerbated the intestinal injury, which might be related to the 5-HT and TRPV signaling.

The assessment of risk factors for long-term survival outcome in ypN0 patients with rectal cancer after neoadjuvant therapy and radical anterior resection

BACKGROUND

The main negative prognostic factors in patients with rectal cancer after radical treatment include regional lymph node involvement, lymphovascular invasion, and perineural invasion. However, some patients still develop cancer recurrence despite the absence of the above risk factors. The aim of the study was to assess clinicopathological factors influencing long-term oncologic outcomes in ypN0M0 rectal cancer patients after neoadjuvant therapy and radical anterior resection.

METHODS

A retrospective survival analysis was performed on a group of 195 patients. We assessed clinicopathological factors which included tumor regression grade, number of lymph nodes in the specimen, Charlson comorbidity index (CCI), and colorectal anastomotic leakage (AL).

RESULTS

In the univariate analysis, AL and CCI > 3 had a significant negative impact on disease-free survival (DFS), disease-specific survival (DSS), and overall survival (OS). After the division of ALs into early and late ALs, it was found that only patients with late ALs had a significantly worse survival. The multivariate Cox regression analysis showed that CCI > 3 was a significant adverse risk factor for DFS (HR 5.78, 95% CI 2.15-15.51, p < 0.001), DSS (HR 7.25, 95% CI 2.25-23.39, p < 0.001), and OS (HR 3.9, 95% CI 1.72-8.85, p = 0.001). Similarly, late ALs had a significant negative impact on the risk of DFS (HR 5.05, 95% CI 1.97-12.93, p < 0.001), DSS (HR 10.84, 95% CI 3.44-34.18, p < 0.001), and OS (HR 4.3, 95% CI 1.94-9.53, p < 0.001).

CONCLUSIONS

Late AL and CCI > 3 are the factors that may have an impact on long-term oncologic outcomes. The impact of lymph node yield on understaging was not demonstrated.

Simultaneous totally robotic rectal resection and partial nephrectomy: case report and review of literature

Introduction

The incidence of synchronous RCC and colorectal cancer is heterogeneous ranging from 0.03 to 4.85%. Instead, only one case of huge colon carcinoma and renal angiomyolipoma was reported. The treatment of synchronous kidney and colorectal neoplasm is, preferably, synchronous resection. Currently, laparoscopic approach has shown to be feasible and safe, and it has become the gold standard of synchronous resection due to advantages of minimally invasive surgery. We presented a case synchronous renal neoplasm and colorectal cancer undergone simultaneous totally robotic renal enucleation and rectal resection with primary intracorporeal anastomosis. As our knowledge, this is the first case in literature of simultaneous robotic surgery for renal and colorectal tumor.

Case presentation

A 53-year-old woman was affected by recto-sigmoid junction cancer and a solid 5 cm left renal mass. We performed a simultaneous robotic low anterior rectal resection and renal enucleation. Total operative time was 260 min with robotic time of 220 min; estimated blood loss was 150 ml; time to flatus was 72 h, and oral diet was administered 4 days after surgery. The patient was discharged on the eighth post-operative day without peri- and post-operative complication. The definitive histological examination showed a neuroendocrine tumor pT2N1 G2, with negative circumferential and distal resection margins. Renal tumor was angiomyolipoma. At 23 months follow-up, the patient is recurrence free.

Discussion and conclusion

As our knowledge, we described the first case in literature of simultaneous robotic anterior rectal resection and partial nephrectomy for treatment of colorectal tumor and renal mass. Robotic rectal resection with intracorporeal anastomosis surgery seems to be feasible and safe even when it is associated with simultaneous partial nephrectomy. Many features of robotic technology could be useful in combined surgery. This strategy is recommended only when patients’ medical conditions allow for longer anesthesia exposure. The advantages are to avoid a delay treatment of second tumor, to reduce the time to start the post-operative adjuvant chemotherapy, to avoid a second anesthetic procedure, and to reduce the patient discomfort. However, further studies are needed to evaluate robotic approach as standard surgical strategy for simultaneous treatment of colorectal and renal neoplasm.

Is a drain necessary after anterior resection of the rectum? A systematic review and meta-analysis

OBJECTIVE

The anastomotic leak rate in colorectal surgery is highest in patients receiving anterior rectal resections. The placement of prophylactic pelvic drains remains a routine option for preventing postoperative leaks, despite increasing evidence suggesting no clinical benefit. The present study seeks to identify a consensus on the use of prophylactic drains in anterior rectal resections.

METHODS

A systematic search was conducted of MEDLINE, Scopus, EMBASE, and Cochrane Library databases to identify clinical trials comparing the use of drainage to non-drainage in cases of colorectal anastomosis.

RESULTS

Three randomized clinical trials (RCTs) and two controlled clinical trials (CCTs) were identified that met the inclusion criteria, with a total of 1702 patients with rectal cancer who underwent anterior resection: 1206 with a pelvic drain and 496 without a pelvic drain. Meta-analysis showed that the use of a drain did not significantly improve the outcomes of anastomotic leaks; the overall reoperation rate during the 30-day postoperative period and the postoperative mortality were statistically lower in the drained group (OR 2.82, 95% CI 1.33 to 5.97; I² = 0%).

CONCLUSIONS

The use of prophylactic pelvic drainage after anterior rectal resections does not provide significant benefits with respect to anastomotic leaks and overall complication rates. However, an approximately threefold reduction of the postoperative mortality of the drained patients was observed. Given the limitations of the present study, these findings warrant the use of a drain after anterior rectal resection. Nevertheless, due to the low quality of the available data, further multicenter trials with uniform inclusion criteria are needed to evaluate drain usage in the anterior rectal resection.

Long-term functional follow-up after anterior rectal resection for cancer

PURPOSE

This is a retrospective analysis including all of the patients that have undergone anterior resection for rectal cancer from January 1998 to December 2005 in two tertiary referral centers. The study aims to evaluate the long term functional results after low anterior resection and to identify the risk factors of postoperative bowel disorders.

METHOD

Data were collected from the clinical records, and then the low anterior resection syndrome score which is a specific questionnaire to investigate the symptoms after surgery was submitted to the selected patients. Exclusion criteria were intra-abdominal rectal cancer, partial mesorectal excision, permanent stoma, recurrent local disease, and patients who declined the questionnaire.

RESULTS

A total of 93 patients were included in the analysis with a median age at the diagnosis of 66 years. The median follow-up was 13.7 years, and low anterior resection syndrome was reported in 44 patients (47.5 %), with major manifestations in 19 patients (20.5 %), and minor symptoms in 25 patients (27 %). Age more than 70 years, tumor distance from the external anal verge, neoadjuvant treatment, and interval time of closing stoma are independent prognostic factors of functional disorders after surgery.

CONCLUSIONS

Because of its great impact on the quality of life of these patients, it is necessary to early identify the syndrome trying to reduce its manifestations. Moreover, the symptoms seem to remain stable 1 year after surgery; hence, it is important to have an exhaustive, preoperative counseling and an integrated post-operative functional and rehabilitational follow-up in association with the oncologic pathway.

Impact of a diverting stoma in an enhanced recovery programme for rectal cancer

PURPOSE

The association of a loop ileostomy decreases the severity of complications after rectal surgery but can increase the postoperative stay. The aim of this study is to investigate if a diverting ileostomy influences the postoperative outcomes in a series of patients included in a multimodal rehabilitation program (MMRP).

METHODS

We analyzed a series of 104 patients that underwent elective surgery with primary anastomosis for rectal adenocarcinoma using a MMRP: 66 men and 38 women, with a median age of 64 (IQR: 55-75) years. Group A included patients with an associated loop ileostomy, and Group B, those without a protective stoma.

RESULTS

Group A = 58, group B = 46 patients without differences in age, ASA, BMI and other risk factors, nor in the surgical approach (laparoscopic in 34%), although there were more neoadjuvant treatments in group A: 77.5 vs. 36.9%; P=.001. In group A, the most common operation was total mesorectal excision (96%) and in the B, a subtotal mesorectal excision (90%). There were no differences in postoperative complications (Group A 34.4 vs. group B28.2%; P=.322), anastomotic leaks (8.3 vs. 10.8%; P=.475), or postoperative ileus (20.7 vs. 10.9%; P=.140), neither in postoperative stay (7.9 vs. 6.9 days; P= .058, readmissions (7 vs. 13.6%; P= .22), or postoperative stay, including readmissions (8.4 vs. 9.1 days; P= .49).

CONCLUSIONS

The association of a loop ileostomy does not extend the length of stay nor increases the rate of complications in patients that underwent a rectal resection with anastomosis included in a MMRP.