Perioperative characterization of anastomotic doughnuts with high-resolution probe-based confocal laser endomicroscopy in colorectal cancer surgery: a feasibility study

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.

Probe-based confocal laser endomicroscopy for evaluating the submucosal invasion of colorectal neoplasms

BACKGROUND

Probe-based confocal laser endomicroscopy (pCLE) is a novel method for in vivo histological analysis of colorectal neoplasm mucosa, which provides meaningful information for the development of adequate therapeutic strategies. However, the in vivo histology of colorectal neoplasm submucosa has not been studied. We assessed the feasibility and safety of pCLE for evaluating colorectal submucosa, and identified and validated diagnostic criteria for submucosal carcinoma infiltration.

METHODS

From March to July 2014, 83 pCLE videos of 51 lesions in 31 patients who underwent scheduled colonoscopic procedures for the removal of colorectal neoplasms were acquired consecutively. During the procedures, pCLE videos of the lesions and biopsy samples for histopathological analysis were acquired. Final histopathological results were used as the gold standard.

RESULTS

Based on the confocal pattern, we classified colorectal submucosa findings as negative (superficial submucosa, deep submucosa, and submucosa with fibrosis) or indicative of carcinoma infiltration. Dark and irregular cell nests with irregular cell architecture and little or no mucin were seen in submucosal carcinoma infiltration. Based on rates of correlation with pathological findings, the sensitivity, specificity, and accuracy of the classification of submucosal carcinoma infiltration by two observers were 91.7, 86.8, and 88.0 %, respectively. In addition, the results showed good interobserver agreement for the detection of submucosal carcinoma infiltration (κ = 0.757, standard error = 0.102). No adverse events occurred during the procedures.

CONCLUSIONS

Submucosa assessment by pCLE is feasible and safe. pCLE is useful for the differentiation of normal submucosa from carcinoma infiltration, particularly when infiltration is accompanied by severe fibrosis. Large-scale prospective studies are needed to further evaluate the clinical impact of the use of pCLE during endoscopy.

In vivo assessment of tumour angiogenesis in colorectal cancer: the role of confocal laser endomicroscopy

AIM

Tumour neoangiogenesis is a key factor in tumour progression and metastatic spread and the possibility to assess tumour angiogenesis might provide prognostic information. The aim of this study was to establish the role of probe-based confocal laser endomicroscopy (p-CLE) in the identification of vascular architecture and specific morphological patterns in normal colorectal mucosa and malignant lesions during routine endoscopy.

METHOD

Fourteen consecutive patients with colorectal cancer were included. The following features were identified and then compared between normal and neoplastic mucosa on p-CLE images: vessel shape (straight vs irregular) vessel diameter the 'branching patterns' vessel permeability (fluorescein leakage) and blood flow (normal vs defective flux). Immunohistochemistry was used to confirm the presence and to study the morphology of vascular structures (CD-34 staining) and 'neo-vessels' (WT-1 staining) on tumour and normal mucosal sections.

RESULTS

Tumour vessels appeared as irregular, ectatic and with a highly variable calibre and branching patterns on p-CLE images. The mean diameter of tumour vessels was significantly larger than those in normal mucosa (weighted mean difference 3.38, 95% CI 2.65-4.11, P = 0.01). Similarly, 'vessel branching' (OR 2.74, 95% CI 1.23-6.14, P = 0.01), fluorescent dye 'extravasation' (OR 3.46, 95% CI 1.39-8.57, P = 0.01) were significantly more frequent in colorectal cancer than in normal colorectal mucosa. Immunohistochemistry corroborated the p-CLE findings, showing higher vascularity in tumour sections due to neoformed vessels, presenting irregular patterns.

CONCLUSION

Probe-based confocal laser endomicroscopy provides a noninvasive characterization of the microvascular architecture of colonic mucosa. Different morphological patterns have been described, discriminating normal and malignant microvascular networks in colorectal mucosa.

Confocal laser endomicroscopy in breast surgery: a pilot study

BACKGROUND

Breast neoplasms include different histopathological entities, varying from benign tumors to highly aggressive cancers. Despite the key role of imaging, traditional histology is still required for a definitive diagnosis. Confocal Laser Endomicroscopy (CLE) is a new technique, which enables to obtain histopathological images in vivo, currently used in the diagnosis of gastrointestinal diseases. This is a single-center pilot feasibility study; the main aim is to describe the basic morphological patterns of Confocal Laser Endomicroscopy in normal breast tissue besides benign and malignant lesions.

METHODS

Thirteen female patients (mean age 52.7, range from 22 to 86) who underwent surgical resection for a palpable breast nodule were enrolled. CLE was performed soon after resection with the Cellvizio® Endomicroscopy System (Mauna Kea Technologies, Paris, France), by using a Coloflex UHD-type probe; intravenous fluorescein was used as contrast-enhancing agent. The surgical specimen was cut along the main axis; dynamic images were obtained and recorded using a hand-held probe directly applied both to the internal part of the lesion and to several areas of surrounding normal tissue. Each specimen was then sent for definitive histologic examination.

RESULTS

Histopathology revealed a benign lesion in six patients (46%), while a breast cancer was diagnosed in seven women (54%). Confocal laser endomicroscopy showed some peculiar morphological patterns. Normal breast tissue was characterized by a honeycomb appearance with regular, dark, round or hexagonal glandular lobules on a bright stroma background; tubular structures, representing ducts or blood vessels, were also visible in some frames. Benign lesions were characterized by a well-demarcated "slit-like" structure or by lobular structures in abundant bright stroma. Finally, breast cancer was characterized by a complete architectural subversion: ductal carcinoma was characterized by ill-defined structures, with dark borders and irregular ductal shape, formingribbons, tubules or nests; mucinous carcinoma showed smaller cells organized in clusters, floating in an amorphous extracellular matrix.

CONCLUSIONS

This is the first pilot study to investigate the potential role of confocal laser imaging as a diagnostic tool in breast diseases. Further studies are required to validate these results and establish the clinical impact of this technique.