Diagnosis and Management of Rectal Neuroendocrine Tumors (NETs).

Rectal neuroendocrine tumors (NETs) are rare, with an incidence of 0.17%, but they represent 12% to 27% of all NETs and 20% of gastrointestinal NETs. Although rectal NETs are uncommon tumors, their incidence has increased over the past few years, and this is probably due to the improvement in detection rates made by advanced endoscopic procedures. The biological behavior of rectal NETs may be different: factors predicting the risk of metastases have been identified, such as size and grade of differentiation. The tendency for metastatic diffusion generally depends on the tumor size, muscular and lymphovascular infiltration, and histopathological differentiation. According to the current European Neuroendocrine Tumor Society (ENETS) guidelines, tumors that are smaller than 10 mm and well differentiated are thought to have a low risk of lymphovascular invasion, and they should be completely removed endoscopically. Rectal NETs larger than 20 mm have a higher risk of involvement of muscularis propria and high metastatic risk and are candidates for surgical resection. There is controversy over rectal NETs of intermediate size, 10-19 mm, where the metastatic risk is considered to be 10-15%: assessment of tumors endoscopically and by endoanal ultrasound should guide treatment in these cases towards endoscopic, transanal, or surgical resection.

Endorectal Ultrasonography and Pelvic Magnetic Resonance Imaging Show Similar Diagnostic Accuracy in Local Staging of Rectal Cancer: An Update Systematic Review and Meta-Analysis.

BACKGROUND: Endorectal Ultrasonography (EUS-ERUS) and pelvic magnetic resonance imaging (MRI) are world-wide performed for the local staging of rectal cancer (RC), but no clear consensus on their indications is present, there being literature in support of both. The aim of this meta-analysis is to give an update regarding the diagnostic test accuracy of ERUS and pelvic MRI about the local staging of RC. MATERIALS AND METHODS: A systematic literature search from November 2020 to October 2021 was performed to select studies in which head-to-head comparison between ERUS and MRI was reported for the local staging of rectal cancer. Quality and risk of bias were assessed with the QUADAS-2 tool. Our primary outcome was the T staging accuracy of ERUS and MRI for which pooled accuracy indices were calculated using a bivariable random-effects model. In addition, a hierarchical summary receiver operating characteristic curve (hSROC) was created to characterize the accuracy of ERUS and MRI for the staging of T and N parameters. The area under the hSROC curve (AUChSROC) was determined as a measure of diagnostic accuracy. RESULTS: Seven studies and 331 patients were included in our analysis. ERUS and MRI showed a similar accuracy for the T staging, with AUChSROC curves of 0.91 (95% C.I., 0.89 to 0.93) and 0.87 (95% C.I., 0.84 to 0.89), respectively (p = 0.409). For T staging, ERUS showed a pooled sensitivity of 0.82 (95% C.I. 0.72 to 0.89) and pooled specificity of 0.91 (95% C.I. 0.77-0.96), while MRI had pooled sensitivity and specificity of 0.69 (95% C.I. 0.55-0.81) and 0.88 (95% C.I. 0.79-0.93), respectively. ERUS and MRI showed a similar accuracy in the N staging too, with AUChSROC curves of 0.92 (95% C.I., 0.89 to 0.94) and 0.93 (95% C.I., 0.90 to 0.95), respectively (p = 0.389). CONCLUSIONS: In conclusion, ERUS and MRI are comparable imaging techniques for the local staging of rectal cancer.

The Role of Micro-RNAs and Circulating Tumor Markers as Predictors of Response to Neoadjuvant Therapy in Locally Advanced Rectal Cancer.

The response to neoadjuvant chemoradiation (nCRT) is a critical step in the management of locally advanced rectal cancer (LARC) patients. Only a minority of LARC patients responds completely to neoadjuvant treatments, thus avoiding invasive radical surgical resection. Moreover, toxic side effects can adversely affect patients' survival. The difficulty in separating in advances responder from non-responder patients affected by LARC highlights the need for valid biomarkers that guide clinical decision-making. In this context, microRNAs (miRNAs) seem to be promising candidates for predicting LARC prognosis and/or therapy response, particularly due to their stability, facile detection, and disease-specific expression in human tissues, blood, serum, or urine. Although a considerable number of studies involving potential miRNA predictors to nCRT have been conducted over the years, to date, the identification of the perfect miRNA signatures or single miRNA, as well as their use in the clinical practice, is still representing a challenge for the management of LARC patients. In this review, we will first introduce LARC and its difficult management. Then, we will trace the scientific history and the key obstacles for the identification of specific miRNAs that predict responsiveness to nCRT. There is a high potential to identify non-invasive biomarkers that circulate in the human bloodstream and that might indicate the LARC patients who benefit from the watch-and-wait approach. For this, we will critically evaluate recent advances dealing with cell-free nucleic acids including miRNAs and circulating tumor cells as prognostic or predictive biomarkers.

Combined surgical and negative pressure therapy to treat multiple enterocutaneous fistulas and abdominal abscesses: A case report.

INTRODUCTION: We report the case of a successful management with combined aggressive surgery and negative pressure therapy, to treat a severely ill-septic patient, affected by multiple chronic enterocutaneous fistulas. PRESENTATION OF CASE: A 26-year-old female patient presented with multiple pelvic and intra-abdominal abscesses, enterocutaneous fistulas and central venous catheter-related bacteraemia in extremely poor general conditions.The patient underwent both an abdominal CT which showed multiple digestive loops stuck and apparently fistulised and an abdominal-pelvic MRI, confirming the CT findings, and demonstrating a third fistula involving the Pouch and responsible for a pelvic and retroperitoneal chronic abscess.Given the patient's septic condition, despite several attempts of conservative therapies, an aggressive surgical approach was adopted.After temporary abdominal wall closure, the patient underwent Vacuum Assisted Closure therapy in order to close the abdominal wall and drain the residual abscess. The patient was discharged at the 35th post-operative day in good general conditions. DISCUSSION: This case is about a complex, long-lasting clinical scenario, progressively leading a young woman to death despite several attempts of conservative therapy, sometimes allowed to treat enterocutaneous fistulas. The use of negative pressure therapy to manage open abdomen is still controversial. Patients affected by enterocutaneous fistulas are in need of adequate nutritional support due to their hypercatabolic state, secondary both to the fluid loss and the concomitant inflammatory status. CONCLUSION: When conservative management fails and the patient shows septic complications, a multidisciplinary aggressive approach, including surgery, negative-pressure therapy and hyperbaric oxygen therapy is required to treat this life-threatening condition.

Oncological Outcomes and Quality of Life After Rectal Cancer Surgery.

Surgery for rectal cancer has been completely revolutionized thanks to the adoption of new technologies and up-to-date surgical procedures that have been applied to the traditional milestone represented by Total Mesorectal Excision (TME). The multimodal and multidisciplinary approach, with new technologies increased the patients' life expectancies; nevertheless, they have placed the surgeon in front of newer issues, represented by both oncological outcomes and the patients' need of a less destructive surgery and improved quality of life. In this review we will go through laparoscopic, robotic and transanal TME surgery, to show how the correct choice of the most appropriate technique, together with a deep knowledge of oncological principles and pelvic anatomy, is crucial to pursue an optimal cancer treatment. Novel technologies might also help to decrease the patients' fear of surgery and address important issues such as cosmesis and improved preservation of postoperative functionality.

Gastrocolic trunk of Henle and its variants: review of the literature and clinical relevance in colectomy for right-sided colon cancer.

PURPOSE: Venous vascular anatomy of the right colon presents a high degree of variability. Henle's Gastrocolic Trunk is considered an important anatomical landmark by colorectal surgeons. The classical description concerns a bipod vascular structure or tripod, but several variants are associated to it. The aim of this study is to merge the most updated literature on the anatomy knowledge of the Gastrocolic Trunk by evaluating all possible variants, as well as to underline its surgical importance due to its topographical relationships. METHODS: Twelve studies describing the anatomy of the gastrocolic trunk were selected, each of them dealing with a more or less extensive series of cases. A distinction was drawn between the gastropancreatic trunk, devoid of the colonic component, and the gastrocolic trunk; and then the frequency of the different resulting variants was reported. The data obtained from cadavers and radiological studies were analyzed separately. RESULTS: The Gastrocolic Trunk is found in 74% of cadaver studies, and in 86% of radiological studies. Its most frequent configuration is represented by the union of right gastroepiploic vein + anterior superior pancreaticoduodenal vein + superior right colic vein, respectively, 32.5% and 42.5%, followed by the right colic vein which replaces (26.9%, 12.3%) or is added (10%, 20.1%) to the superior right colic vein. CONCLUSIONS: The superior right colic vein joins the right gastroepiploic vein and the anterior superior pancreaticoduodenal vein thus forming, in most cases, the gastrocolic trunk. The anatomical knowledge of vascular structures forms the basis for both the interpretation of preoperative radiological images and the surgical procedure itself, despite the considerable anatomical variability of tributaries.

Serrated Lesions of the Colon-Rectum: A Focus on New Diagnostic Tools and Current Management.

Prompt diagnosis and correct management of the so called "serrated lesions" (SLs) of the colon-rectum are generally considered of crucial importance in the past years, mainly due to their histological heterogeneity and peculiar clinical and molecular patterns; sometimes, they are missed at conventional endoscopy and are possibly implicated in the genesis of interval cancers. The aim of this review is to focus on the diagnostic challenges of serrated lesions, underlying the role of both conventional endoscopy and novel technologies. We will show how an accurate and precise diagnosis should immediately prompt the most appropriate therapy other than defining a proper follow-up program. It will be emphasized how novel endoscopic techniques may provide better visualization of mucosal microsurface structures other than enhancing the microvascular architecture, in order to better define and characterize specific patterns of mucosal lesions of the gastrointestinal tract. Standard therapy of SLs of the colon-rectum is still very debated, also due to the relatively lack of studies focusing on treatment issues. The high risk of incomplete resection, together with the high rate of postcolonoscopy interval cancers, suggests the need of an extra care when facing this kind of lesions. Given this background, we will outline useful technical tips and tricks in the resection of SLs, taking aspects such as the size and location of the lesions, as well as novel available techniques and technologies, other than future perspectives, including confocal laser endomicroscopy into consideration. Follow-up of SLs is another hot topic, also considering that their clinical impact has been misunderstood for a long time. The incidence of the so called interval colorectal cancer underlines how some weaknesses exist in current screening and follow-up programs. Considering the lack of wide consensus for the management of some SLs, we will try to summarize and clarify the best strategies for their optimal management.