Seminars in Colon and Rectal Surgery最新文献

Our understanding of the pathophysiology of pilonidal disease continues to evolve. In this manuscript we would like to review the current thinking about plausible causes of pilonidal disease. Based on our current understanding of this benign disorder, we offer seven potential strategies to minimize the development of symptomatic disease and recurrence. Finally, we share some ideas about future research.

Transanal approaches are an important modality for the diagnosis and treatment of rectal neoplasia while allowing for organ preservation. Choosing the appropriate surgical approach based on anatomy, pathology, platform capabilities and surgical skill is paramount to success. In this article we review preoperative considerations, the present options for transanal approach and the relative advantages and disadvantages they each offer. We will focus on advanced transanal options including robotic-assisted approaches and endoscopic submucosal resection.

Transanal excision is an important approach in the management of diseases of the rectum. Most notably, advances in transanal excision technique have evolved with efforts to safely excise rectal tumors. There have been many important advancements over the past several thousand years to reach this frontier. In this article, we review the interesting history behind transanal surgery. We begin with the ancient Egyptians and Greeks who performed transanal surgery with high mortality, and end with contemporary approaches, which minimize patient morbidity. Transanal surgery is now an accepted approach in selected patients as a result of overcoming three obstacles: 1) the ability to perform these operations safely; 2) the importance of performing an oncologically sound resection; and 3) technical advances in surgical exposure. What has resulted is a rapidly evolving new era in transanal surgery.

Transanal minimally invasive surgery (TAMIS) is a technique that allows high quality local excision of benign rectal neoplasms and early-stage rectal cancers. These lesions can be located more proximal that those treated with conventional transanal excision. Operative costs are minimized and access to the technique is expanded with utilization of conventional laparoscopic instruments. Good oncologic outcomes can be achieved for local excision of early rectal cancers, but its role in the surgical treatment of more advanced tumors is still being evaluated. As with all surgical techniques, appropriate training must be ensured and continued assessment of oncologic outcomes maintained.

Rectal neuroendocrine tumors (NETs) have increased in prevalence due to increased detection via endoscopic screening for colorectal neoplasia, advances and availability of imaging tools along with the indolent nature of the tumor. Imaging techniques to identify rectal NETs include computed tomography, magnetic resonance imaging, and endoscopic rectal ultrasound. Rectal NETs are typically categorized by tumor size to determine if they should undergo endoscopic resection, local excision or transanal excision, or a radical resection, as per National Comprehensive Cancer Network guidelines. However, while examining the literature, multiple studies have examined outcomes for patients who did not adhere to these guidelines and had similar recurrence rates and survival as those patients who did. Therefore, we propose less aggressive treatment for rectal NETs in the absence of adverse features.

Local excision (LE) for early-stage rectal cancer is an attractive option compared to total mesorectal excision (TME), as it avoids many of the significant comorbidities and adverse functional outcomes associated with TME. However, LE for tumors with high-risk histopathologic features can lead to unacceptably high rates of local and distant recurrence. Neoadjuvant or adjuvant chemoradiotherapy can mitigate those risks in certain clinical settings and may expand the number of patients who can be safely treated with an organ-preserving approach. In this chapter, we will explore the available date supporting the use of neoadjuvant and adjuvant chemoradiation (CRT) for the treatment of high-risk early-stage rectal cancer and will discuss future studies that aim to answer some of the ongoing clinical questions related to this practice.

Local excision is a well-tolerated, low risk, curative oncologic operative approach for highly selected early-stage rectal cancers. As with any cancer treatment, cure is balanced with morbidity and quality of life. In this respect, the best management for a patient with an early rectal cancer highlights the clinical dilemma balancing concerns for over- versus under-treatment. That is to say, radical resection may be oncologically equivalent to local excision for true early stage cancer, yet, results in much greater morbidity, including the possibility of a permanent colostomy. Alternatively, local excision of a presumed early rectal cancer may be oncologically inferior to mesorectal excision, potentially compromising the cancer outcome dramatically. Navigating between these two surgical extremes requires incorporation of multiple critical clinico-pathologic variables, including accurate clinical staging, precise tumor localization, careful histologic assessment to recognize higher risk features, and patient fitness and preference.

While pelvic failure following local excision is generally more common than after radical resection, the gap between disease-free and overall survival is not quite as wide, particularly among lower-risk pT1Nx cancers in patients following LE. The lack of histologic lymph node staging and reliance on imperfect imaging to risk estimate micrometastatic mesorectal nodal disease, the higher morbidity associated with completion mesorectal excision pursued for a histologically higher-risk early rectal cancer, and the greater risk of an extended resection at salvage operation for locoregional recurrence collectively emphasize the degree of caution when considering a more limited excisional operative approach.

Conventional transanal excision allows a direct endoluminal approach through a natural orifice, avoiding the life altering presence of a stoma and associated morbidity and mortality of transabdominal surgery. Benign polyps and early-stage rectal cancer within the low to mid rectum can be definitively treated with transanal excision, with few complications, typically in an outpatient fashion. Other minimally invasive approaches outlined in this issue may demonstrate less specimen fragmentation, higher rate of negative margins, and decreased recurrence, but are often impractical for excising lesions in the low rectum.

Anastomotic leak is a devastating complication of gastrointestinal surgery that is associated with high morbidity and mortality. Yet, despite flawless technique in the operating room, many anastomoses still leak, suggesting that factors beyond tension and ischemia contribute to anastomotic leak. In this article, we will review the accumulating evidence that the gut microbiome plays a critical role in anastomotic healing, and then review methods of minimizing perturbances to the gut microbiome to decrease rates of anastomotic leak.

Formation of intestinal anastomosis is a commonly encountered procedure in abdominal surgery, and construction of these anastomoses should be considered an essential and basic aspect of the art of colon and rectal surgery. This chapter covers specific technical and physiological details relevant to the construction of sound intestinal anastomoses, discusses operative considerations for some specific anastomosis types commonly encountered and colon and rectal surgery, and reviews intraoperative testing and troubleshooting of anastomotic construction. Intraoperative assurance of a well perfused, tension-free, and technically secure anastomosis is the first and most essential principle for a good anastomotic outcome.