Tumor localization for laparoscopic colorectal surgery

Spillage of endoscopic tattoo before laparoscopic colectomy: A case report and literature search

ABSTRACT

Endoscopic tattooing with India ink is a common practice before the laparoscopic resection of polyps/tumours. Sometimes, due to inadvertent intramuscular instead of submucosal injection, it may lead to peritoneal spillage precluding the laparoscopic approach and warrant open resection. There are a few reports of post-operative abdominal sepsis. We report a case where spillage led to open conversion due to poor visibility and post-operative abdominal sepsis necessitating a change of antibiotics and prolonged hospital stay. Surgeons should be aware of these complications from this apparently innocuous step. We also did a review of the literature to see how this can be prevented and what alternative approaches have been developed.

Novel endoscopic tattooing dye based on polyvinylpyrrolidone-modified polydopamine nanoparticles for labeling gastrointestinal lesions

Endoscopic tattooing is a localization technique that is particularly important for identifying gastrointestinal lesions for follow-up and subsequent treatment. However, the dyes currently used for endoscopic tattooing have a short tattooing time, high cost, and many side effects. Herein, we designed and prepared polydopamine (PDA) nanoparticles modified with polyvinylpyrrolidone (PVP) for endoscopic tattooing using a physical encapsulation method. PDA has good stability and high adhesion properties, and its stability was further enhanced after PVP modification. In vitro and in vivo tests demonstrated that PDA/PVP has good biosafety. Endoscopic tattooing with PDA/PVP in a porcine model showed that the dye could be stabilized in the digestive tract for at least 60 days. Furthermore, our research results demonstrated that PDA/PVP has excellent reactive oxygen species (ROS) and reactive nitrogen species (RNS) scavenging ability and can promote wound healing. Overall, the strategy proposed herein will lead to the use of an innovative dye for endoscopic tattooing of gastrointestinal lesions.

Safety and efficacy of autologous blood tattooing for preoperative colonic localization: a comparative study with conventional India ink tattooing

BACKGROUND

India ink has been a popular choice for a tattooing agent in preoperative endoscopic localization but often results in unfavorable effects. Subsequently, autologous blood tattooing has arisen as an alternative option. Due to the limited availability of comparative studies on the matter, we conducted a study to compare the perioperative outcomes associated with India ink tattooing versus autologous blood tattooing.

METHODS

A total of 96 patients who underwent minimally invasive surgical procedures for left-sided colonic neoplasm following preoperative endoscopic localization were included in the study. These patients were categorized into two groups: 36 patients who received India ink tattooing and 60 patients who underwent autologous blood tattooing. The perioperative outcomes including procedure-related outcomes and postoperative outcomes were compared between the two groups.

RESULTS

There was no significant difference in visibility and spillage of tattooing agent between India ink group and autologous blood group. However, India ink group showed a higher incidence of post-tattooing fever, higher level of postoperative C-reactive protein level, longer time to first flatus, resumption of surgical soft diet, and duration of hospital stay, and a higher occurrence of postoperative complications including ileus and surgical site infection compared with the autologous blood group. In the multivariate analysis, India ink tattooing was significantly associated with the occurrence of postoperative complications. In the subgroup analysis involving patients with intraperitoneal spillage, the autologous blood group demonstrated significantly favorable perioperative outcomes compared with India ink group.

CONCLUSIONS

Autologous blood tattooing demonstrated comparable visibility and enhanced safety, establishing it as a potential alternative to India ink for preoperative endoscopic localization.

A Green Lantern for the Surgeon: A Review on the Use of Indocyanine Green (ICG) in Minimally Invasive Surgery

Indocyanine green (ICG) fluorescence imaging has revolutionized surgical practice across various medical and surgical specialties. This article reviews the clinical applications of ICG in abdominal, urological, thoracic, and gynecological surgery. ICG fluorescence imaging has been widely adopted in general surgery for various applications, including perfusion assessment, intraoperative visualization of the ureter, and tumor localization. It is particularly valuable in evaluating anastomotic leaks and aiding in precise tumor resection during minimally invasive surgeries. Studies have shown mixed results on its effectiveness in reducing anastomotic leak rates, highlighting the need for further research. In thoracic surgery, ICG facilitates the identification and resection of pulmonary bullae, as well as the precise localization of pulmonary nodules during video-assisted surgery. In urology, ICG aids in localizing renal tumors and guiding selective arterial occlusion during partial nephrectomy. Its role in identifying the lymphatic pathway in prostate cancer and sentinel lymph node biopsy in gynecological cancer is also discussed. Despite its benefits, the use of ICG fluorescence faces challenges such as limited tissue penetration, the potential for false results, a lack of standardized protocols, and high equipment costs. Nonetheless, it remains a powerful tool that could improve surgical outcomes.

The use of mixed reality in the preoperative planning of colorectal surgery: Preliminary experience with a narrative review

New advanced technologies have recently been developed and preliminarily applied to surgery, including virtual reality (VR), augmented reality (AR) and mixed reality (MR). We retrospectively review all colorectal cases in which we used holographic 3D reconstruction from February 2020 to December 2022. This innovative approach was used to identify vascular anomalies, pinpoint tumor locations, evaluate infiltration into neighboring organs and devise surgical plans for both training and educating trainee assistants. We have also provided a state-of-the-art analysis, briefly highlighting what has been stated by the scientific literature to date. VR facilitates training and anatomical assessments, while AR enhances training and laparoscopic performance evaluations. MR, powered by HoloLens, enriches anatomic recognition, navigation, and visualization. Successful implementation was observed in 10 colorectal cancer cases, showcasing the effectiveness of MR in improving preoperative planning and its intraoperative application. This technology holds significant promise for advancing colorectal surgery by elevating safety and reliability standards.

Diagnostic Benefits and Surgical Implications of Methods for Tumor Localization in Sigmoid and Rectum Tumors

(1) Background: In our study, we aimed to determine the accuracy rates of imaging methods for sigmoid, rectosigmoid colon, and rectum cancer. (2) Methods: Patients with tumors located in the rectosigmoid colon, sigmoid colon, and rectum who were operated on were included. Upon admission, we examined the patients' first diagnostic colonoscopies and their preoperative repeat control colonoscopies and computed tomography (CT) report. (3) Results: In this study, 23 patients (57.5%) were male. The overall accuracy rates were 80.0% (32/40) in colonoscopy, 65.0% (26/40) in preoperative CT, and 87.5% (35/40) in retro CT, and the differences among the examination methods were statistically significant (p = 0.049). The sensitivity levels decreased to 50.0% for colonoscopy and preoperative CT and 75.0% for retro CT in rectosigmoid colon tumors. In rectal tumors, the sensitivity levels were 75.0% in colonoscopy, 60.0% in preoperative CT, and 80.0% in retro CT. In two patients, the tumor location was given incorrectly, and postoperative pathological evaluations indicated T3N0 tumors; the initially planned treatment was thus changed to include radiotherapy in addition to chemotherapy in the postoperative period because the tumor was located in the middle rectum. (4) Conclusions: Accuracy in tumor localization in sigmoid, rectosigmoid, and rectum tumors still needs to be improved, which could be accomplished with prospective studies. CT evaluations for cancer localization in this patient group should be re-evaluated by a radiologist.

Implementation of Synoptic Reporting for Endoscopic Localization of Complex Colorectal Neoplasms

Introduction  Lack of documented tattooing of colorectal neoplasms at index colonoscopy results in high repeat preoperative colonoscopy rates. We developed national consensus recommendations for endoscopic localization and piloted an electronic synoptic reporting template. We report on the implementation and perceptions of using synoptic reporting to enhance colorectal lesion marking in a central Canadian healthcare system.  Methods We implemented the template within our endoscopy reporting system and ran an infographic education campaign. We then conducted a follow-up email-based interview with all regional endoscopists. Thematic analysis and a mixed-methods triangulation approach were employed to synthesize qualitative and quantitative data.  Results The interview was completed by 28/52 endoscopists (54%). Most (60.7%; n = 17) completed >100 colonoscopies and 71.4% (n = 20) identified six to 20 neoplasms requiring tattooing since introduction. A total of 50% (n = 14) used the template. Those not using it were unaware of it (42.9%; n = 12), or preferred using narrative text (17.9%; n = 5). Users reported modest mean functionality scores (intuitiveness: 3.56/5; efficiency: 3.7/5) and high impact scores (credible: 4.22/5; informative: 4.21/5). However, the perception of the synoptic template's ability to reduce the repeat preoperative colonoscopy rate was more circumspect (3.76/5). Conclusions Endoscopists believed the synoptic template was a functional, impactful tool that would improve communication and help to decrease the repeat preoperative colonoscopy rate. However, synoptic template uptake was limited by provider awareness, therefore more educational efforts are needed to increase uptake.

Tumor Segmentation in Colorectal Ultrasound Images Using an Ensemble Transfer Learning Model: Towards Intra-Operative Margin Assessment

Tumor boundary identification during colorectal cancer surgery can be challenging, and incomplete tumor removal occurs in approximately 10% of the patients operated for advanced rectal cancer. In this paper, a deep learning framework for automatic tumor segmentation in colorectal ultrasound images was developed, to provide real-time guidance on resection margins using intra-operative ultrasound. A colorectal ultrasound dataset was acquired consisting of 179 images from 74 patients, with ground truth tumor annotations based on histopathology results. To address data scarcity, transfer learning techniques were used to optimize models pre-trained on breast ultrasound data for colorectal ultrasound data. A new custom gradient-based loss function (GWDice) was developed, which emphasizes the clinically relevant top margin of the tumor while training the networks. Lastly, ensemble learning methods were applied to combine tumor segmentation predictions of multiple individual models and further improve the overall tumor segmentation performance. Transfer learning outperformed training from scratch, with an average Dice coefficient over all individual networks of 0.78 compared to 0.68. The new GWDice loss function clearly decreased the average tumor margin prediction error from 1.08 mm to 0.92 mm, without compromising the segmentation of the overall tumor contour. Ensemble learning further improved the Dice coefficient to 0.84 and the tumor margin prediction error to 0.67 mm. Using transfer and ensemble learning strategies, good tumor segmentation performance was achieved despite the relatively small dataset. The developed US segmentation model may contribute to more accurate colorectal tumor resections by providing real-time intra-operative feedback on tumor margins.

Preoperative fluorescent clip marking vs. India ink tattooing for tumor identification during colorectal surgery

PURPOSE

Identifying tumor location is important in colorectal tumor resection. Preoperative endoscopic India ink marking is a widespread practice, but local injection of ink is an unstable procedure. Although it is often invisible, the ink may be sprayed into the peritoneal cavity and contaminate the surgical field. At our hospital, we introduced fluorescent clip marking (FCM) using the Zeoclip FS®, an endoscopic clip developed using near-infrared fluorescent resin. We tested the usefulness of FCM by retrospectively comparing cases in which FCM was used with cases in which conventional ink marking was used.

METHODS

We enrolled 305 patients with colorectal tumors who underwent colorectal surgery after preoperative marking from January 2017 to April 2022. We classified the patients into the FCM group (86 patients) and the India ink tattoo group (219 patients). Endoscopic marking was completed in the FCM group by the day before surgery, and fluorescence was evaluated during surgery with a fluorescent laparoscopic system. Patient backgrounds, marking visibility, adverse effects, and early postoperative results were retrospectively compared between groups.

RESULTS

Marking was visually confirmed in 80 patients in the FCM group (93.02%) and in 166 patients in the India ink tattoo group (75.80%) (p = 0.0006). In the group with India ink tattoos, contamination of the surgical field was observed in seven cases (3.20%). No adverse events were observed in the FCM group.

CONCLUSION

In colorectal surgery, FCM provides better visibility than the conventional India ink tattooing method and is a simple and safe marking method.

CLINICAL TRIAL REGISTRATION

Examination of fluorescence navigation for laparoscopic colorectal cancer surgery. Research Ethics Committee of the Kawaguchi Municipal Medical Center (Saitama, Japan) approval number: 2020-3. https://kawaguchi-mmc.org/wp-content/uploads/clinicalresearch-r02.pdf .

The Accuracy of Different Modalities Used for Preoperative Primary Tumour Localisation in Operated Colorectal Cancer Patients

Aim Colonoscopy and computed tomography (CT) scans of the abdomen and pelvis are routine pre-operative assessment tools in colorectal cancer (CRC) patients. There have been some discrepancies regarding the location of cancer when seen by colonoscopy versus CT scan. The purpose of this study was to compare the accuracy of a colonoscopy with a computed tomography (CT) scan of the abdomen and pelvis with contrast, which is done routinely before surgery to localise the exact site of the tumour within the large bowel, whilst comparing both to the operative, gross and histopathology findings of the exact location. Methods A retrospective study was carried out on 165 colorectal cancer patients operated on between January 1, 2010, and December 31, 2014, using electronic hospital records that were reviewed anonymously, comparing the location of cancer within the large bowels as was found on colonoscopy and CT scan of the abdomen and pelvis with contrast, comparing both to post-operative histopathology specimen or intra-operative assessment in cases where no resection of the primary tumour was performed. Results CT and colonoscopy were both accurate in diagnosing 70.5% of cases that had done both investigations pre-operatively. The best results were obtained when the cancer was located in the caecum as confirmed post-operatively; the combined accuracy rate was 100%. CT was accurate, whilst colonoscopy was not in eight (6.2%) cases (all are rectal or sigmoid cancers), and colonoscopy was accurate and CT was not in 12 cases, 10 of them were rectal and two were ascending colonic. Colonoscopy was not performed in 36 (21%) cases for a variety of reasons, including large bowel obstruction or perforation on presentation. In 32 of these cases, CT scan managed to accurately predict the location of cancer (mostly rectal and caecal), and CT scan was inaccurate in 20.6% of cases (34 out of 165), whilst colonoscopy was inaccurate in 13.9% of cases (18 out of 129). Conclusion Colonoscopy is more accurate in localising colorectal cancers than CT scan of the abdomen and pelvis with contrast. CT scan diagnoses regional and distant spread of colorectal cancers such as nodal status, invasion of neighbouring organs and/or peritoneum and the presence of liver metastases, whilst colonoscopy is limited to intraluminal diagnosis but can be both a diagnostic and therapeutic tool, with higher accuracy, in general, in localising colorectal cancers. Both CT scan and colonoscopy were equal in appendicular, caecal, splenic flexure and descending colon cancer localisation accuracy.

Assessment of Autologous Blood marker localIzation and intraoperative coLonoscopy localIzation in laparoscopic colorecTal cancer surgery (ABILITY): a randomized controlled trial

BACKGROUND

Laparoscopic colorectal surgery has been proved to have similar oncological outcomes with open surgery. Due to the lack of tactile perception, surgeons may have misjudgments in laparoscopic colorectal surgery. Therefore, the accurate localization of a tumor before surgery is important, especially in the early stages of cancer. Autologous blood was thought a feasible and safe tattooing agent for preoperative endoscopic localization but its benefits remain controversial. We therefore proposed this randomized trial to the accuracy and safety of autogenous blood localization in small, serosa-negative lesion which will be resected by laparoscopic colectomy.

METHODS

The current study is a single-center, open-label, non-inferiority, randomized controlled trial. Eligible participants would be aged 18-80 years and diagnosed with large lateral spreading tumors that could not be treated endoscopically, malignant polyps treated endoscopically that required additional colorectal resection, and serosa-negative malignant colorectal tumors (≤ cT3). A total of 220 patients would be randomly assigned (1:1) to autologous blood group or intraoperative colonoscopy group. The primary outcome is the localization accuracy. The secondary endpoint is adverse events related to endoscopic tattooing.

DISCUSSION

This trial will investigate whether autologous blood marker achieves similar localization accuracy and safety in laparoscopic colorectal surgery compared to intraoperative colonoscopy. If our research hypothesis is statistically proved, the rational introduction of autologous blood tattooing in preoperative colonoscopy can help improve identification of the location of tumors for laparoscopic colorectal cancer surgery, performing an optimal resection, and minimizing unnecessary resections of normal tissues, thereby improving the patient's quality of life. Our research data will also provide high quality clinical evidence and data support for the conduction of multicenter phase III clinical trials.

TRIAL REGISTRATION

This study is registered with ClinicalTrials.gov, NCT05597384. Registered 28 October 2022.

Assessing the Association Between Endoscopic Tattooing and Lymph Node Yield in Rectal Cancer

INTRODUCTION

Preoperative endoscopic tattooing is an effective tool for intraoperative tumor localization in colon cancer. Endoscopic tattooing in rectal cancer may have unidentified benefits on lymph node yield, making it easier for pathologists to identify nodes during histopathologic assessment. There remains concern that tattoo ink may alter anatomical planes, increasing surgical difficulty.

METHODS

Retrospective chart reviews from 2016 to 2021 of n = 170 patients presenting with rectal cancer were divided into two groups: with (n = 79) and without (n = 91) endoscopic tattoos. Demographics, operative details, tumor characteristics, prior chemoradiation, and pathologic details were collected. Primary outcome was total lymph node yield. Secondary outcomes were rates of adequate (> 12) nodes, margin status, and operative variables including operative time.

RESULTS

No differences between pathologic stage, tumor height, high inferior mesenteric artery ligation, operative times, conversion rate, or surgical approach (open versus minimally invasive) were noted between groups. Receipt of neoadjuvant chemoradiation was less frequent in the endoscopic tattooing group (53.2% versus 76.9%, P ≤ 0.001). Total node number and rate of adequate lymph node yield were higher with endoscopic tattooing (20.5 ± 7.6 versus 16.8 ± 6.6 lymph nodes and 100.0% versus 83.5% adequate lymph node harvest, both P ≤ 0.001). Rates of positive circumferential and distal margins and complete total mesorectal excision were also similar. Regression analysis identified endoscopic tattooing (Incidence Risk Ratio 1.17, 95% confidence interval 1.04-1.31) and operative time more than 300 min (Incidence Risk Ratio 0.88, 95% confidence interval 0.77-0.99) had significant effects on lymph node harvest. Removal of patients with inadequate lymph node yield resulted in similar rates of total and positive lymph nodes.

CONCLUSIONS

Endoscopic rectal tattooing is associated with increased lymph node yield (including after neoadjuvant chemoradiotherapy) without sacrificing oncologic or perioperative outcomes, although this effect is inconsistent when only considering patients with an adequate lymph node yield.

Computer-aided classification of colorectal segments during colonoscopy: a deep learning approach based on images of a magnetic endoscopic positioning device

OBJECTIVE

Assessment of the anatomical colorectal segment of polyps during colonoscopy is important for treatment and follow-up strategies, but is largely operator dependent. This feasibility study aimed to assess whether, using images of a magnetic endoscope imaging (MEI) positioning device, a deep learning approach can be useful to objectively divide the colorectum into anatomical segments.

METHODS

Models based on the VGG-16 based convolutional neural network architecture were developed to classify the colorectum into anatomical segments. These models were pre-trained on ImageNet data and further trained using prospectively collected data of the POLAR study in which endoscopists were using MEI (3930 still images and 90,151 video frames). Five-fold cross validation with multiple runs was used to evaluate the overall diagnostic accuracies of the models for colorectal segment classification (divided into a 5-class and 2-class colorectal segment division). The colorectal segment assignment by endoscopists was used as the reference standard.

RESULTS

For the 5-class colorectal segment division, the best performing model correctly classified the colorectal segment in 753 of the 1196 polyps, corresponding to an overall accuracy of 63%, sensitivity of 63%, specificity of 89% and kappa of 0.47. For the 2-class colorectal segment division, 1112 of the 1196 polyps were correctly classified, corresponding to an accuracy of 93%, sensitivity of 93%, specificity of 90% and kappa of 0.82.

CONCLUSION

The diagnostic performance of a deep learning approach for colorectal segment classification based on images of a MEI device is yet suboptimal (clinicaltrials.gov: NCT03822390).

Battery-Free Tattooing Mechanism-Based Functional Active Capsule Endoscopy

This paper presents a novel tattooing capsule endoscope (TCE) for delivering a certain amount of ink to the submucosal layer of digestive tract organs. A dual-function permanent magnet is used for locomotion and injection activation. The developed capsule endoscope can move actively in 5 DOF due to the interaction between the permanent magnet and a controllable external magnetic field produced by an electromagnet actuation system. In addition, the permanent magnet is involved in a specially designed mechanism to activate a process that creates a squeezing motion to eject the liquid from the storage room to the target. The dimension of the prototype is 12.5 mm in diameter and 34.6 mm in length. The proposed TCE is tested ex vivo using a fresh porcine small-intestine segment. We were able to direct the TCE to the target and deliver the tattoo agent into the tissue. The proposed mechanism can be used for drug delivery or lesion tattooing, as well as to accelerate the realization of the functional capsule endoscope in practice.

Inking outside the box: systematic review on the utility of tattooing lesions in rectal cancer

PURPOSE

Endoscopic tattooing in rectal cancer is infrequently utilized for fear of tattoo ink obscuring anatomical planes, increasing the difficulty of surgical excision. Colon cancer tattooing has demonstrated increased lymph node yields and increased accuracy in establishing adequate margins. Rectal cancer tattooing may be especially helpful after neoadjuvant chemoradiation, where complete clinical responses could limit lesion identification and lymph node yields are typically less robust. We seek to review and identify the effects of tattooing in rectal cancer.

METHODS

A systematic literature search was performed in PubMed, Embase, and SCOPUS. Studies on endoscopic tattooing with cohorts consisting of at least ≥ 25% of rectal cancer patients were selected. Studies focusing solely on rectal cancer were also reviewed separately.

RESULTS

Of 416 studies identified, 10 studies encompassing 2460 patients were evaluated. Seven studies evaluated lymph node yields; five reported beneficial effects of endoscopic tattooing, while two reported no significant difference. Among four studies reporting lesion localization, successful localization rates were between 63 and 100%. Rates of intraoperative endoscopy performed to reevaluate lesion location ranged from 5.7 to 20%. The distal margin was evaluated in two studies, which reported more accurate placement of the distal resection margin after tattooing. When complications of tattooing were documented (7 studies with 889 patients), only five direct complications of endoscopic tattooing were observed (0.6%).

CONCLUSIONS

Although the data is heterogenous, it suggests that endoscopic tattooing in rectal cancer may improve lymph node yields and assist in determining accurate distal margins without high rates of complication. Further research must be completed before practice management guidelines can change.

TRIAL REGISTRATION

No. CRD42021271784.

Rates and predictors of repeat preoperative endoscopy for elective colorectal resections: how can we avoid repeated procedures?

BACKGROUND

Despite limited endoscopy resources, repeat endoscopy prior to surgery is commonly practised. Our aim was to determine repeat preoperative endoscopy rates and factors influencing this practice at a high-volume Canadian tertiary centre.

METHOD

A retrospective cohort study was conducted on all patients undergoing elective colorectal resections for benign and malignant neoplasms at a tertiary centre in Winnipeg, Canada between 2007 and 2017. Multivariable logistic regression analysis was used to identify predictors of repeat preoperative endoscopy.

RESULTS

Of 1062 patients identified, mean age was 68 years and 56% were male. Rate of repeat preoperative endoscopy was 29%. On multivariable analysis, male sex (OR 1.68, CI 1.19-2.34, p = 0.003) and lesions located in the left colon (OR 2.73, CI 1.79-4.14, p < 0.001), rectosigmoid (OR 9.11, CI 2.14-38.8, p = 0.003), and rectum (OR 4.06, CI 2.58-6.38, p < 0.001) were at increased odds of undergoing repeat preoperative endoscopy. Patients with a tattoo placed at index endoscopy were at markedly lower odds of undergoing repeat preoperative endoscopy (OR 0.48, CI 0.34-0.68, p < 0.001). Index endoscopist specialty was not a significant predictor of repeat endoscopy (OR 0.76, CI 0.54-1.06, p = 0.09).

CONCLUSIONS

Repeat preoperative lower endoscopy is commonly practised and may be unnecessary if appropriate identification and documentation of lesions has been achieved. Tattooing of suspicious lesions is a key modifiable factor associated with reduced likelihood of repeat preoperative endoscopy. This study highlights the need for standardized guidelines and endoscopy reporting practices given the delays and costs associated with repeat preoperative endoscopy.

A single centre audit: repeat pre-operative colonoscopy

BACKGROUND

Repeat colonoscopy may be required for tumour localisation. The aim of the study is to explore the clinical settings it was used and benchmark the quality of initial colonoscopy against standardized guidelines for tumour localisation, tattooing and colonoscopy reporting amongst clinicians.

METHODS

A retrospective study from 2016 to 2021 has been performed on patients who underwent elective colorectal cancer resections at the Northern Hospital. Patient demographics, colonoscopic and operative details were retrieved from the Bi-National Colorectal Cancer Audit (BCCA) Registry database and hospital medical records.

PRIMARY OUTCOMES

changes in operative approach and delays to operation.

SECONDARY OUTCOMES

reasons for a repeat colonoscopy and complications from repeat colonoscopy.

RESULTS

A total of 339 patients were included in this study. 94 (28.6%) underwent a repeat colonoscopy. Re-scoping rate was 29.6% for surgeons, and 26.2% for non-operating endoscopists. Surgeons had a 5.9% localisation error rate, and non-operating endoscopist 6.95% (p = 0.673). Surgeons did not have a lower rate of repeat colonoscopy (p = 0.462). Repeat endoscopy was associated with a longer time to definitive operation (p < 0.001). No complications were associated with a repeat colonoscopy.

CONCLUSION

There was no difference in localisation error rates or repeat colonoscopy amongst surgeons (29.6%) and non-operating endoscopists (26.2%) (p = 0.462). This could be explained by the standardized endoscopy training in Australia governed by a common training board. Lack of tattooing at index colonoscopy and inadequate documentation often led to a repeat endoscopy, which was associated with a longer time to definitive operation. Standardized guidelines in tattooing of lesions and colonoscopy reporting should be implemented.

Clip or Tattooing: A Comparative Study for Preoperative Colon Cancer Endoscopic Localization

Background and Aim

Preoperative endoscopic markers have been extensively used for the localization of colonic neoplastic lesions in laparoscopic surgery. We conducted this respective cohort study to compare the localization accuracy of two commonly used endoscopic marker strategies (endoscopic clip plus abdominal plain film and endoscopic tattooing).

Methods

Patients who received preoperative colonoscopy localization for colonic neoplasia and underwent an elective laparoscopic operation afterward between 2013 and 2020 were included in this retrospective study. The localization accuracy of the two endoscopic strategies was compared, and the predictors of successful endoscopic localization were identified by multivariate regression.

Results

In total, 195 patients [average age 62.4 ± 9.2 years, 123 male (63.1%)] undergoing preoperative colonoscopy localization and subsequent laparoscopic colectomy for colonic neoplasms were included. Endoscopic localization was finally proven to be successful in 150 (76.9%) patients in the surgery. Compared to the tattooing group, patients who had successful localization for colonic lesions were fewer in the clip group (64 of 101 cases, 63.4% vs. 86 of 94 cases, 91.5%, p < 0.001). The multivariate regression analysis showed that the endoscopic tattooing strategy, endoscopic clip strategy, and lesion location were all predictors for successful localization (all with p < 0.001).

Conclusion

Compared with endoscopic clip plus abdominal plain film, endoscopic tattooing had higher localization accuracy and less intraoperative colonoscopy counseling; the endoscopic clip strategy, tattooing strategy, and colonic lesion location were all predictors of successful endoscopic localization.

Autologous blood for preoperative colorectal TUMOR’S localization: A Vietnamese preliminary experience

Introduction

Laparoscopic colorectal surgery (LCRS) is the optimal choice for cases of early cancer. However, due to their early stage, one of this procedure's challenges is tumoral localization. So that, there are many methods of locating tumors preoperatively that have been studied by authors. Recently, Korean authors have reported a method of injecting autologous blood to mark the tumor before surgery with high efficiency and safety. This article aims to evaluate the effectiveness by analyzing the section biopsy's results, as well as the safety of this procedure.

Materials and method

This study is descriptive cross-section study with analysis of retrospective occurrences of case series of colonoscopy with autologous blood before surgery from October 2020 to December 2021.

Results

16 patients were recruited to the study. The average age was 62.9 ± 13.1 with male/female ratio was 8/8. 50% (8/16 patients) of all cases was early carcinomas, and by location, 62.5% of all cases was sigmoid colon tumors. All 16 patients (100%) found the tumor marking position. None of the patients had complications of marked endoscopy such as intestinal perforation, peritonitis, abdominal abscess, intestinal adhesions, etc.

Conclusion

The method of autologous blood injection to locate the tumor before laparoscopic colorectal surgery is a technique that can be performed effectively and safely.

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Laparoscopic colorectal surgery is the optimal choice for cases of early cancer.

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There are some methods of locating tumors preoperatively.

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Colonoscopy autologous blood injection can be performed effectively and safely.

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We can combine other methods to increase the certainty of tumor location.

Value of multi-slice spiral computerized tomography for diagnosis of synchronous colorectal carcinoma: a retrospective study

Objective

To compare the accuracy of multi-slice spiral computerized tomography (MSCT) with colonoscopy for diagnosing synchronous colorectal carcinoma (SCC).

Methods

We retrospectively analyzed all consecutive patients admitted to our institution with colorectal carcinoma between 19 September 2014 and 31 January 2020. Data on SCC patients who had undergone MSCT and colonoscopy were analyzed. Information on tumor location, tumor size, missed diagnosis by MSCT or colonoscopy, T stage, pathological type, and reasons for missed diagnosis was recorded and used to assess the diagnostic accuracies of MSCT and colonoscopy.

Results

Twenty-three cases met the inclusion criteria. MSCT plus colonoscopy had a significantly higher diagnostic accuracy (93.5%) than colonoscopy alone. There were significant differences in missed diagnosis rates of proximal cancer (34.8%) and distal cancer (4.3%) by colonoscopy. For MSCT, the missed diagnosis rate for tumors with a median long diameter of 1.25 cm (interquartile range 0.80, 1.50) was significantly lower than that for larger tumors (long diameter 4.00 cm; 3.00, 6.00).

Conclusions

MSCT is a valuable diagnostic tool for SCC that can effectively minimize the missed diagnosis rate of primary tumors when combined with colonoscopy.

Preoperative Localization in Colonic Surgery (PLoCoS Study): a multicentric experience on behalf of the Italian Society of Colorectal Surgery (SICCR)

The aim of this prospective multicentric study was to compare the accurate colonic lesion localization ratio between CT and colonoscopy in comparison with surgery. All consecutive patients from 1st January to 31st December 2019 with a histologically confirmed diagnosis of dysplastic adenoma or adenocarcinoma with planned elective, curative colonic resection who underwent both colonoscopy and CT scans were included. Each patient underwent conventional colonoscopy and CT to stage the tumour, and the localization results of each procedure were registered. CT and colonoscopic localization were compared with surgical localization, adopted as the reference. Our analysis included 745 patients from 23 centres. After comparing the accuracy of colonoscopy and CT (for visible lesions) in localizing colonic lesions, no significant differences were found between the two preoperative tools (510/661 vs 499/661 correctly localized lesions, p = 0.518). Furthermore, after analysing only the patients who underwent complete colonoscopy and had a visible lesion on CT, no significant difference was observed between conventional colonoscopy and CT (331/427 vs 340/427, p = 0.505). Considering the intraoperative localization results as a reference, a comparison between colonoscopy and CT showed that colonoscopy significantly failed to correctly locate the lesions localized in the descending colon (17/32 vs 26/32, p = 0.031). We did not identify an advantage in using CT to localize colonic tumours. In this setting, colonoscopy should be considered the reference to properly localize lesions; however, to better identify lesions in the descending colon, CT could be considered a valuable tool to improve the accuracy of lesion localization.

Small-Dose Endoscopic Tattooing Using a Novel Needle for Localization Prior to Laparoscopic Surgery of Colorectal Cancer

BACKGROUNDS

Endoscopic tattooing failure by deep mural injection or tattoo leakage-induced massive staining causes localization errors or decreased laparoscopic visualization. To overcome these, we developed a novel tattoo needle with comparatively shorter needle (length, 2.5 mm) and minimal-caliber catheter (volume, 0.3 mL).

AIMS

The single-center, prospective observational study aimed to determine the efficacy and safety of a small-doze endoscopic tattooing prior to laparoscopic surgery for colorectal cancer, using the needle.

METHODS

Patients with colorectal cancer indicated for laparoscopic surgery were recruited. With the novel needle, a single tattoo was created at the anterior wall close to the lesion. During laparoscopic surgery, surgeons assessed the tattoo visibility, tattoo leakage, and the disturbance of laparoscopic view by tattoo leakage. The primary endpoint was an accurate localization by visible tattoo. Secondary endpoints were adverse events related to tattooing, the need for intraoperative endoscopy, and tattoo leakage.

RESULTS

A total of 383 tattoos in 358 patients were analyzed. Accurate tumor localization rate was 96.6% (95% confidence interval [CI]: 94.3-98.0%). No adverse events occurred. Intraoperative colonoscopy was performed in 7 (1.8%) patients with invisible tattoo. Tattoo leakage was found in 4.2% (95%CI: 2.6-6.7%), and leakage disturbed the laparoscopic view of the surgical plane in 0.7% (95%CI: 0.3-2.3%).

CONCLUSIONS

Prior to laparoscopic surgery for colorectal cancer, our endoscopic tattooing with a standardized protocol using a novel needle is considered a simple, highly reliable localization technique with an extremely safe profile, which would be valuable to reduce physician's efforts and redundant medical resources. Trial registration number UMIN000021012. Date of registration: June 2016.

Computed Tomography Colonography Angiography (CTC-A) prior to colectomy for cancer: A new tool for surgeons

The pre-operative work-up for non-metastatic colon cancer includes colonoscopy and thoraco-abdomino-pelvic computed tomography (CT) with intravenous (IV) contrast. Colonoscopic determination of the anatomical location of the tumor may be erroneous, particularly with a long redundant colon (dolichocolon), and the search for synchronous colon neoplasms is limited when the endoscope cannot traverse the tumor-bearing segment. While computed tomography colonography angiography (CTC-A) makes it possible to assess distant tumor metastasis, it remains limited for the assessment of loco-regional extension. CTC-A requires specific colonic preparation, controlled colonic insufflation with CO₂, and an injection of IV contrast. CTC-A provides a 3-D view of the overall morphology of the colon and precisely localizes the site of the colonic tumor. Merging the images of the colon with those of mesenteric and colonic vessels provides a representation of anatomical vascular variations. This information could help the surgeon to better plan the colectomy. The use of two-dimensional images of CTC-A with sections perpendicular to the major axis of the tumor-bearing colonic segment can provide precise information on the degree of parietal extension and be useful in evaluating the value of neo-adjuvant chemotherapy.

Tattooing or Metallic Clip Placement? A Review of the Outcome Surrounding Preoperative Localization Methods in Minimally Invasive Anterior Resection Performed at a Single Center

BACKGROUND

For minimally invasive colorectal surgery, preoperative localization is a typical procedure. We here aimed to analyze compared 2 different localization methods in terms of short-term outcomes, like the operative outcome and postoperative complication rates based on real-world data.

MATERIALS AND METHODS

This was a retrospective analysis study conducted at a medical center. We enrolled patients who were presented with colonic tumor between January 1, 2016, and December 31, 2019, and they had undergone laparoscopic anterior resection in a single institution. Data included patient characteristics, operative outcome, length of hospital stay, and postoperative complications.

RESULTS

The preoperative localization group had a better resection margin (4 vs. 3 cm; P<0.001) and fewer procedures of intraoperative colonoscopy (4.67% vs. 18.22%; P=0.002). Lymph node harvest occurred more in patients with endoscopic tattooing procedures than with metallic clip procedures (25 vs. 20; P=0.031). No significant difference was found regarding postoperative complications and the length of hospital stay.

CONCLUSIONS

Preoperative localization in a laparoscopic anterior resection led to better surgical planning and resection margin. The metallic clip placement was helpful in the preoperative localization and setting. The endoscopic tattooing method had a larger lymph node harvest and with fewer intraoperative colonoscopy.

The efficacy and safety of indocyanine green-hyaluronic acid mixture (LuminoMark™) for localization in patients with non-palpable breast lesions: a multi-center open-label parallel phase-2 clinical trial

BACKGROUND

Increasing rates of breast cancer screening have been associated with an increasing frequency of non-palpable breast lesions detection. Preoperative breast lesion localization is essential for optimizing excision accuracy. This study aimed to evaluate the efficacy and safety of indocyanine green (ICG) hyaluronic acid injection as a novel mixture for localization.

METHODS

We performed a prospective clinical trial with female patients who underwent surgery for non-palpable breast lesions. All patients were sequentially assigned to the control group (localization with activated charcoal), Test Group 1 (ICG-hyaluronic acid mixture 0.1 mL), or Test Group 2 (ICG-hyaluronic acid mixture 0.2 mL) by 1:1:1 ratio.

RESULTS

A total of 44 patients were eligible for this study (Control Group = 14, Test Group 1 = 15, Test Group 2 = 15 patients). Fibroadenoma (n = 17, 38.6%) accounted for the largest proportion of diagnoses, and five patients (11.4%) were diagnosed with malignancies. There were no statistically significant differences in baseline characteristics among the three groups. The marking rate was over 86% in all groups, with no significant intergroup differences. Skin pigmentation was only observed in the control group. The mean accuracy of resection (the greatest diameter of the excised specimen divided by the greatest diameter of the preoperative lesion as observed using ultrasonography, with values closer to 1 reflecting a higher accuracy) was 3.7 in the control group, 2.2 in Test Group 1, and 2.1 in Test Group 2 (p = 0.037 between Controls and Test Group 1, p = 0.744 between Test Group 1 and Test Group 2, and p = 0.026 between Controls and Test Group 2).

CONCLUSION

ICG-hyaluronic acid injection is a novel method that was shown to accurately localize non-palpable breast lesions and was associated with no skin pigmentation. Further research is required to apply this method to malignant breast lesions. Trial registration "A Multicenter Open-label, Parallel, Phase 2 Clinical Trial to Evaluate the Efficacy and Safety of LuminoMark™ Inj. (Conc. for Fluorescence) Localization in Patients with Non-palpable Breast Lesions" was prospectively registered as a trial (ClinicalTrials. gov Identifier: NCT03743259, date of registration: May 29, 2018, https://clinicaltrials.gov/ct2/show/NCT03743259 ).

Intraoperative Colonoscopy During Colorectal Surgery Does Not Increase Postoperative Complications: An Assessment From the ACS-NSQIP Procedure-targeted Cohort

Intraoperative colonoscopy (IOC) is an adjunct in colorectal surgery to detect the location of the lesions and assessing anastomotic integrity. The authors aimed to evaluate the safety and feasibility and postoperative morbidity of IOC in left-sided colectomy patients for colorectal cancer. Patients undergoing elective left-sided colectomy without any proximal diversion for colorectal cancer between 2013 and 2016 were reviewed from the American College of Surgeons National Surgical Quality Improvement Program procedure-targeted database. Demographics, comorbidities, short-term outcomes, and postoperative morbidity of patients were evaluated. A total of 8811 patients were identified and IOC was performed for 1143 (12.97%) patients. There was no significant difference in postoperative complications between the IOC and non-IOC groups. Patients with IOC had shorter total hospital length of stay. The use of IOC does not adversely affect short-term outcomes after colorectal resections. Surgeons may utilize IOC liberally for left-sided colorectal resections.

Preoperative Colonoscopic Tattooing Using a Direct Injection Method with Indocyanine Green for Localization of Colorectal Tumors: An Efficacy and Safety Comparison Study

Purpose

Methods

Results

Conclusion

Small Efforts Can Prevent Big Mistakes: Preoperative Colonoscopic Tattooing Using Indocyanine Green

The importance of tumor localization is increasing because the application of laparoscopic surgery in colon cancer surgery is on the rise and the incidence of early cancer is also rising. There are several methods of tumor localization, but the most popular method is preoperative colonoscopic tattooing. Various tattooing agents are used, and among them, India ink is the most widely used agent. However, it is impossible to use India ink in Korea. Therefore, research on other alternative agents is needed.

Predictors and rates of prior endoscopic tattoo localization amongst individuals undergoing elective colorectal resections for benign and malignant lesions

BACKGROUND

Appropriate tattooing of suspicious lesions during colonoscopy is critical for surgical planning. However, variability exists in tattoo placement, technique, and reporting. Our aim is to determine the rates and predictors of tattoo placement, tattoo location in relation to the lesion, and localization accuracy during lower endoscopy for individuals undergoing elective colorectal resections.

METHODS

We performed a retrospective chart review on all patients undergoing elective colorectal resections for benign and malignant neoplasms between 2007 and 2017 at a high volume Canadian tertiary centre. Patient demographics, endoscopic, and tumour-related characteristics were collected. Multivariable logistic regression analysis was used to identify predictors of tattoo localization.

RESULTS

Of the 1062 patients identified, laparoscopic resection occurred in 59% of patients. 57% of patients underwent tattooing for tumour localization at index endoscopy. Tattoos were placed distal (27%), both proximal and distal (4%), and just proximal (2%) to the lesion. However, in the majority of cases the tattoo location was not documented (67%). On multivariate analysis, patients who had lesions located in the transverse colon (OR: 1.93, 95% CI 1.04-3.59), had surgery performed after 2010 (2011-2014: OR: 1.88, 95% CI 1.31-2.68; 2015-2017: OR: 2.87, 95% CI 1.93-4.26), underwent laparoscopic resections (OR: 1.69, 95% CI 1.22-2.33), and had their index endoscopy performed in an urban setting (OR: 5.92, 95% CI 3.23-10.87), were at higher odds of having a tattoo placed at index endoscopy.

CONCLUSION

Endoscopic tattoo placement and location in relation to the lesion varies widely, with reports containing suboptimal documentation. Lesion location and laparoscopic procedures were significant predictors of tattoo placement. This study highlights the need for standardized tattooing practices and reporting amongst endoscopists. One of the focus of quality improvement efforts should be educational initiatives for rural endoscopists.

The Usefulness of Preoperative Colonoscopic Tattooing with Autologous Blood for Localization in Laparoscopic Colorectal Surgery

Purpose

In colorectal cancer surgery, it is important to have accurate resection margins. However, it is challenging to localize lesions during laparoscopy. Therefore, to reduce surgical errors, many preoperative localizing methods have been introduced. In this study, we aimed to assess the preoperative feasibility and safety of autologous blood tattooing.

Methods

A total of 11 patients underwent preoperative colonoscopic autologous blood tattooing from August 2017 to February 2020. At the start of the surgery, the surgeon assessed the patients for the precision of visibility and other complications such as abscess or spillage. The patients’ characteristics, outcomes, and complications were collected retrospectively.

Results

The study comprised 8 men and 3 women, with an average age of 63 years. Ten patients showed precise visibility, and no localization errors were observed during surgery. No complication was observed in all patients.

Conclusion

Preoperative autologous blood tattooing is a very useful and safe technique because it has high visibility with no complications. This method does not require additional agents or facilities. A large-scale study will be required to develop standard guidelines.

Endoscopic tattooing for colorectal lesions: impact on quality of care and patient outcomes

INTRODUCTION

The National Bowel Cancer Screening Programme guidelines advocate the use of endoscopic tattooing for suspected malignant lesions to assist identification and to facilitate laparoscopic resections. However, endoscopic tattooing practices are variable in endoscopic units, resulting in repeat endoscopy and delay in patient management. The aim of this study was to assess the adherence to tattoo protocol for significant colonic lesions at an endoscopy unit in a large district general hospital.

MATERIALS AND METHODS

Prospectively collected data were analysed for 252 patients with significant colonic lesions between January 2017 and December 2018. Data were collected through reviewing patient's notes, histopathology findings and endoscopy reports. Data on lesions, complications, number and site of tattoo placed, and any repeat endoscopy for a tattoo were collected.

RESULTS

Of the 252 patients, 88% (n = 222) had malignant and 12% (n = 30) had benign lesions. Only 58.7% (n = 148) of those patients who had colonoscopy had tattoo placement reported. Of these 148 cases, the report stated the distance of tattoo in relation to the lesion in only 46% (n = 68) of patients. Unfortunately, 14.3% (n = 36) of patients required repeat endoscopy to tattoo the lesions prior to surgery.

CONCLUSIONS

Our study highlights the lack of uniformity of tattoo practice among endoscopists. Despite the National Bowel Cancer Screening Programme guidelines, a significant proportion of colorectal lesions are still not tattooed during their first endoscopy. Some patients had to have repeat endoscopy just for the purpose of tattooing. Active involvement and participation of all endoscopists in the colorectal and the complex polyp multidisciplinary teams may help to improve the tattoo service.

New inductive proximity sensor platform for precise localization of small colorectal tumors

Location of small gastric or colorectal tumors during a laparoscopic procedure is often imprecise and can be misleading. There is a real need for a compatible and straightforward tool that can be used intraoperatively to help the surgeon in this regard. We emphasize in the present work on the fabrication of a new and innovative inductive proximity switch architecture, fully compatible with laparoscopic surgery and with direct application in precise localisation of bowel tumors. An electromagnetic detection probe optimized for laparoscopic surgery and preconditioned for sterilisation was designed and constructed. Various metallic markers designed to be attached to the gastrointestinal mucosa were used for detection by the probe, from standard endoscopic and laparoscopic haemostatic clips to other custom made tags. Experiments were performed in dry and wet-lab experimental laboratory environment using ex-vivo segments of calf's small bowel and colonic surgical specimens from human patients. The dry-lab detection range varied considerably depending on the metallic component of the tags, from 0.5 mm for the endoscopic hemostatic clip to 3.5 mm for the 0.9 mm thickness stainless-steel custom tags. The latter was actually detectable from the serosal side of the fresh colonic surgical specimens in 85% of the attempts if the scanned area was less than 150 cm2 and less than 2 mm of fat was interposed between the probe and the bowel. The newly designed system has the potential to discover metallic tags attached to the bowel mucosa for precise intraoperative laparoscopic location of digestive tumors. Further work is in progress to increase the sensitivity and detection range of the system in order to make it fully compatible with the clinical use.

Lesion Retrieval, Specimen Handling, and Endoscopic Marking in Colonoscopy

Retrieval of lesions after endoscopic polypectomy enables histopathologic analysis and guides future surgical management and endoscopic surveillance intervals. Various techniques and devices have been described with distinct advantages and disadvantages to accomplish retrieval. Appropriate histopathologic analysis depends on lesion handling and preparation. How lesions are handled further depends on size, endoscopic appearance, and removal technique. Endoscopic marking or tattooing is a well-described process that uses dye mediums to leave longstanding marks in the colon. Techniques, dye mediums, and locations within the colon influence tattoo approach.

[Preoperative imaging for colorectal cancer: surgeons' perspective]

Preoperative radiological diagnostics in patients with colorectal cancer has several objectives. The diagnostic localization of the colonic tumor is essential for planning the resection. The radiologically suspected infiltration of neighboring structures may lead to the decision for neoadjuvant treatment. In patients with rectal carcinomas, the T and N stages, the distance to the circumference resection margin (CRM), and the penetration of the tumor into the mesentery must be determined. This crucial to determine whether the patient should undergo neoadjuvant treatment. Prior to the planned relocation of an upstream stoma, radiological diagnostics may be added to clinical and endoscopic assessment but should not be routinely used.

New marking method involving a light-emitting diode and power source device to localize gastrointestinal cancer in laparoscopic surgery

Although the preoperative endoscopic marking method using dye is widely used, the dye can spread into the tissue or abdominal cavity, inducing the inflammation and leading to the wrong dissection. We developed a novel marking method using an endoscopic clip with a light emitting diode (LED) and a power source device to detect the accurate location of the site of interest. We performed this new marking method in three patients with gastrointestinal cancers. We placed an endoscopic clip with an LED on the gastrointestinal mucosa and used a power source device outside of the human body to detect the LED. We detected the clip with the LED using the power source device. We also confirmed the usefulness of this clip in three of three (100%) patients with colorectal and gastric cancer. We developed a novel marking device using an LED to identify an objective location successfully.

Determination of Tumor Location in Rectosigmoid Carcinomas: Difficulties in Preoperative Diagnostics

Differentiation between rectal and sigmoid carcinomas is a diagnostic challenge with important implications for further treatment. Depending on the tumor stage, treatment for rectal carcinoma consists of preoperative (chemo)radiotherapy and surgery. Sigmoid carcinomas are treated with surgery alone. We established the diagnostic accuracy of flexible endoscopy, MRI and/or CT scan, and both modalities combined as reflected by the conclusion of our multidisciplinary team (MDT). Furthermore, we assessed the treatment consequences of misdiagnosis. Consecutive patients were included who underwent surgery from January 2012 to January 2017 for colorectal carcinoma located ≤20 cm from the anal verge as determined by flexible colonoscopy. Diagnostic accuracy of MRI/CT, flexible endoscopy and the final MDT conclusion were analyzed as index test. The location of the tumor during surgery and the type of surgery was the reference standard. We included 293 patients. Flexible endoscopy had a diagnostic accuracy of 90% and for MRI/CT scanning this was 86–87%. Combination of both modalities improved diagnostic accuracy to 96%. Due to misdiagnosis during initial staging, three patients (1%) erroneously underwent neoadjuvant treatment and in two patients neoadjuvant treatment was potentially erroneously omitted. In conclusion, the combination of both flexible endoscopy and MRI/CT (the MDT conclusion) improves diagnostic accuracy. Erroneous clinical diagnosis can lead to under- and overtreatment.

Axillary Lymph Node Tattooing and Targeted Axillary Dissection in Breast Cancer Patients Who Presented as cN+ Before Neoadjuvant Chemotherapy and Became cN0 After Treatment

INTRODUCTION

Targeted axillary dissection (TAD) is an alternative to axillary dissection for breast cancer patients who presented as cN+ before neoadjuvant chemotherapy (NAC) and became cN0 after treatment. TAD is defined as the removal of sentinel lymph nodes (SLNs) along with the pre-NAC marked positive nodes. Tattooing is an option to mark positive nodes. In this study we aimed to investigate the identification rate of tattooed nodes during surgery, correspondence between tattooed nodes and SLNs, and difficulties and pitfalls of the method.

PATIENTS AND METHODS

In 75 patients who were cN+, with axillary lymph nodes known to have or suspected to have disease were tattooed pre-NAC with a sterile carbon suspension (Spot). After NAC completion all patients became cN0 and underwent TAD as an axillary staging procedure.

RESULTS

SLNs were identified successfully in 70 of 75 patients (93.3%). All tattooed nodes were identified successfully intraoperatively in 71 of 75 patients (94.6%). Retrieval of all tattooed nodes in surgical specimens was achieved in 74 patients (98.6%). Correspondence between tattooed nodes and SLNs was observed in 53 of 70 patients (75.3%). In 34 patients (45.3%) the number of pigmented nodes in pathological examination was greater than the number of initially tattooed nodes, indicating the possibility of tattoo ink migration.

CONCLUSION

Tattoo of axillary lymph nodes is a feasible, accurate, and low-cost method of positive node marking pre-NAC. Pathological confirmation of black pigment in the lymph nodes excised is not by itself warranty of retrieval of all marked node because of tattoo ink migration from one node to another. Intraoperative identification using visual inspection is essential.

Minimally Invasive Colon Cancer Surgery

Colon cancer is the second leading cause of cancer death in the United States. Advances in surgical resection techniques, including minimally invasive colectomy, are becoming a standard of care. The oncologic principles of colectomy have included adequate lymphadenectomy, proximal ligation of primary vessels, and resection with adequate longitudinal margins. More recently, complete mesocolic excision has been advocated. Open and minimally invasive approaches must accomplish the same outcomes. This article focuses on the surgical principles of colon cancer, perioperative considerations, and technical aspects of minimally invasive colectomy. We review the current literature regarding oncologic and short-term outcomes of minimally invasive surgery.

Usefulness of colonic tattooing using indocyanine green in patients with colorectal tumors

AIM

To prove that tattooing using indocyanine green (ICG) is feasible in laparoscopic surgery for a colon tumor.

METHODS

From January 2012 to December 2016, all patients who underwent laparoscopic colonic surgery were retrospectively screened, and 1010 patients with colorectal neoplasms were included. Their lesions were tattooed with ICG the day before the operation. The tattooed group (TG) included 114 patients, and the non-tattooed group (NTG) was selected by propensity score matching of subjects based on age, sex, tumor staging, and operation method (n = 228). In total, 342 patients were enrolled. Between the groups, the changes in [Delta (Δ), preoperative-postoperative] the hemoglobin and albumin levels, operation time, hospital stay, oral ingestion period, transfusion, and perioperative complications were compared.

RESULTS

Preoperative TG had a shorter operation time (174.76 ± 51.6 min vs 192.63 ± 59.9 min, P < 0.01), hospital stay (9.55 ± 3.36 d vs 11.42 ± 8.23 d, P < 0.01), and post-operative oral ingestion period (1.58 ± 0.96 d vs 2.81 ± 1.90 d, P < 0.01). The Δ hemoglobin (0.78 ± 0.76 g/dL vs 2.2 ± 1.18 g/dL, P < 0.01) and Δ albumin (0.41 ± 0.44 g/dL vs 1.08 ± 0.39 g/dL, P < 0.01) levels were lower in the TG. On comparison of patients in the “N0” and “N1 or N2” groups, the N0 colon cancer group had a better operation time, length of hospital stay, oral ingestion period, Δ hemoglobin, and Δ albumin results than those of the N1 or N2 group. The operation methods affected the results, and laparoscopic anterior resection (LAR) showed similar results. However, for left and right hemicolectomy, both groups showed no difference in operation time or hospital stay.

CONCLUSION

Preoperative tattooing with ICG is useful for laparoscopic colectomy, especially in the N0 colon cancer group and LAR.

"Is CT Scan more Accurate than Endoscopy in Identifying Distance from the Anal Verge for Left Sided Colon Cancer? A Comparative Cohort Analysis"

Purposes: Accurately localizing colorectal cancer during surgery may be challenging due to intraoperative limitations. In the present study, localization of left-sided colon cancer (LCC) by CT scan is compared to colonoscopy. Material and methods: Consecutive patients with LCC located by colonoscopy and CT scan and undergoing left-hemicolectomy were included. Tumor distance from the anal verge (TDAV) was calculated by both CT-scan and colonoscopy, and then compared, using as reference TDAV measured intraoperatively. Statistical analysis was performed including (1) comparison of means between all three TDAVs, (2) comparison of mean differences between all three TDAVs, (3) comparison of number of patients with a difference between endoscopic TDAV and intraoperative TDAV ≤5 cm and the number of patients with a difference between CT scan TDAV and intraoperative TDAV ≤5 cm (4) statistical relationship between either CT scan and endoscopic and intraoperative TDAVs. Results: Both CT scan and endoscopy overestimate TDAV (25.8 ± 12.5 cm and 24.6 ± 10.6 cm vs. 21.5 ± 7.4 cm, p = 0.005), but CT scan TDAV resulted as being different from intraoperative TDAV (p < 0.01). Regression analysis reported an increasing divergence of measurements with increasing values of intraoperative TDAV, which resulted greater for CT. Tumors within 5 cm of intraoperative TDAV were 22/28 (78.6%) for endoscopy, and 17/28 (60.7%) for CT (p = 0.2448). Conclusions: Accuracy of both examinations seems poor, with a mean overestimation >3 cm and a significant number of tumors found at >5 cm from preoperative evaluation. Preoperative examinations' bias increase proportionally with TDAV length, decreasing their interest especially for tumors located at a greater distance from anal verge.

The added clinical value of performing CT colonography in patients with obstructing colorectal carcinoma

Background

A small percentage of incomplete optical colonoscopies (OCs) are the result of an obstructing tumor. According to current guidelines, CT colonography (CTC) is performed to prevent missing a synchronous tumor. The aim of this study was to evaluate how frequently a synchronous tumor was found on CTC and how often this led to a change in the surgical plan.

Methods

In this retrospective study, a total of 267 patients underwent CTC after an incomplete OC as a result of an obstructing colorectal carcinoma (CRC). Among them, 210 patients undergoing surgery met the inclusion criteria and were included in the analysis. The OC report, CTC report and surgical report of these patients were retrospectively evaluated for the presence of synchronous tumors using surgery and post-operative colonoscopy as the gold standard.

Results

Six of the 210 patients (2.9%) showed signs of a synchronous CRC proximal to the obstructing tumor on CTC. In three of these patients, a synchronous CRC was confirmed during surgery. All these tumors caused a change in the surgical plan. Three out of the six tumors found on CTC were found to be large, non-malignant polyps. All these polyps were located in the same segment as the obstructing tumor and therefore did not alter the surgical plan.

Conclusion

In patients with obstructing CRC, the frequency of synchronous CRCs proximal to this lesion is low. Performing a CTC leads to a change in surgical plan based on the presence of these synchronous tumors in 1.4% of the cases. CTC should be employed as a one-stop shop in patients with an obstructing CRC.

Preoperative Tattooing Using Indocyanine Green in Laparoscopic Colorectal Surgery

Purpose

The aim of the present study was to evaluate the usefulness of indocyanine green (ICG) as a preoperative marking dye for laparoscopic colorectal surgery.

Methods

Between March 2013 and March 2015, 174 patients underwent preoperative colonoscopic tattooing using 1.0 to 1.5 mL of ICG and saline solution before laparoscopic colorectal surgery. Patients’ medical records and operation videos were retrospectively assessed to evaluate the visibility, duration, and adverse effects of tattooing.

Results

The mean age of the patients was 65 years (range, 34–82 years), and 63.2% of the patients were male. The median interval between tattooing and operation was 1.0 day (range, 0–14 days). Tattoos placed within 2 days of surgery were visualized intraoperatively more frequently than those placed at an earlier date (95% vs. 40%, respectively, P < 0.001). For tattoos placed within 2 days before surgery, the visualization rates by tattoo site were 98.6% (134 of 136) from the ascending colon to the sigmoid colon. The visualization rates at the rectosigmoid colon and rectum were 84% (21 of 25) and 81.3% (13 of 16), respectively (P < 0.001). No complications related to preoperative ICG tattooing occurred.

Conclusion

Endoscopic ICG tattooing is more useful for the preoperative localization of colonic lesions than it is for rectal lesions and should be performed within 2 days before laparoscopic surgery.

Model-based Iterative Reconstruction in Low-radiation-dose Computed Tomography Colonography: Preoperative Assessment in Patients with Colorectal Cancer

RATIONALE AND OBJECTIVES

To assess the effect of model-based iterative reconstruction (MBIR) on image quality and diagnostic performance of low-radiation-dose computed tomography colonography (CTC) in the preoperative assessment of colorectal cancer.

MATERIALS AND METHODS

This study included 30 patients with colorectal cancer referred for surgical treatment. All patients underwent CTC with a standard dose (SD) protocol in the supine position and a low-dose (LD; radiation dose reduction of approximately 85%) protocol in the prone position. The SD protocol images were post-processed using filtered back projection (FBP), whereas the LD protocol images were post-processed using FBP and MBIR. Objective and subjective image quality parameters were compared among the three different methods. Preoperative evaluations, including site, length, and tumor and node staging were performed, and the findings were compared to the postsurgical findings.

RESULTS

The mean image noise of SD-FBP, LD-FBP, and LD-MBIR images was 17.3 ± 3.2, 40.5 ± 10.9, and 11.2 ± 2.0 Hounsfield units, respectively. There were significant differences for all comparison combinations among the three methods (P < .01). For image noise, the mean visual scores were significantly higher for SD-FBP and LD-MBIR than for LD-FBP, and the scores for SD-FBP and LD-MBIR were equivalent (3.9 ± 0.3 [SD-FBP], 2.0 ± 0.5 [LD-FBP], and 3.7 ± 0.3 [LD-MBIR]). Preoperative information was more accurate under SD-FBP and LD-MBIR than under LD-FBP, and the information was comparable between SD-FBP and LD-MBIR.

CONCLUSION

MBIR can yield significantly improved image quality on low-radiation-dose CTC and provide preoperative information equivalent to that of standard-radiation-dose protocol.

Instrumental Mechanoreceptoric Palpation in Gastrointestinal Surgery

Background and Aims

Small gastric or colorectal tumours can be visually undetectable during laparoscopic surgeries, and available methods still do not provide a 100% localisation rate. Thus, new methods for further improvements in tumour localisation are highly desirable. In this study, we evaluated the usage of the Medical Tactile Endosurgical Complex (MTEC) in gastrointestinal surgery for localisation of tumours. The MTEC provides the possibility of instrumental mechanoreceptoric palpation, which serves as an analogue of conventional manual palpation.

Methods

Ninety-six elective surgeries were performed, including 48 open surgeries, 43 laparoscopies, and 5 robot-assisted surgeries. The 20 mm version of the MTEC tactile mechanoreceptor was used in open surgeries, and the 10 mm version in laparoscopic and robot-assisted surgeries.

Results

The mean time of instrumental mechanoreceptoric palpation was 3 minutes 12 seconds for open surgeries, which constituted the early stage of the learning curve, and 3 minutes 34 seconds for laparoscopic surgeries. No side effects or postoperative complications related to instrumental mechanoreceptoric palpation were observed, and this procedure provided data sufficient for tumour localisation in more than 95% of cases.

Conclusion

Instrumental mechanoreceptoric palpation performed using MTEC is a simple, safe, and reliable method for tumour localisation in gastrointestinal laparoscopic surgery.

Enhanced Visualization: From Intraoperative Tissue Differentiation to Augmented Reality

Background

Optimal visualization of the operative field and methods that additionally provide supportive optical information form the basis for target-directed and successful surgery. This article strives to give an overview of current enhanced visualization techniques in visceral surgery and to highlight future developments.

Methods

The article was written as a comprehensive review on this topic and is based on a MEDLINE search and ongoing research from our own group and from other working groups.

Results

Various techniques for enhanced visualization are described comprising augmented reality, unspecific and targeted staining methods, and optical modalities such as narrow-band imaging. All facilitate our surgical performance; however, due to missing randomized controlled studies for most of the innovations reported on, the available evidence is low.

Conclusion

Many new visualization technologies are emerging with the aim to improve our perception of the surgical field leading to less invasive, target-oriented, and elegant treatment forms that are of significant benefit to our patients.

Diagnostic utility of staging abdominal computerized tomography and repeat endoscopy in detecting localization errors at initial endoscopy in colorectal cancer

BACKGROUND

Colonoscopy has a reported localization error rate as high as 21% in detecting colorectal neoplasms. Preoperative repeat endoscopy has been shown to be protective against localization errors. There is a paucity of literature assessing the utility of staging computerized tomography (CT) and repeat endoscopy as diagnostic tools for detecting localization errors following initial endoscopy. The objective of this study is to determine the diagnostic characteristics of staging CT and repeat endoscopy in correcting localization errors at initial endoscopy.

METHODS

A retrospective cohort study was conducted at a large tertiary academic center between January 2006 and August 2014. All patients undergoing surgical resection for CRC were identified. Group comparisons were conducted between (1) patients that underwent only staging CT (staging CT group), and (2) patients that underwent staging CT and repeat endoscopy (repeat endoscopy group). The primary outcome was localization error correction rate for errors at initial endoscopy.

RESULTS

594 patients were identified, 196 (33.0%) in the repeat endoscopy group, and 398 (77.0%) patients in the staging CT group. Error rates for each modality were as follows: initial endoscopy 8.8% (95% CI 6.5-11.0), staging CT 9.3% (95% CI 6.5-11.0), and repeat endoscopy 2.6% (95% CI 0.3-4.7); p < 0.01. Repeat endoscopy was superior to staging CT in correcting localization errors for left-sided / rectal lesions (81.2% vs. 33.3%; p < 0.01), right-sided lesions (80.0% vs. 54.5%; p = 0.21), and overall lesions (80.8% vs. 42.3%; p < 0.01). Repeat endoscopy compared to staging CT demonstrated relative risk reduction of 66.7% (95% CI 22-86%), absolute risk reduction of 38.5% (95% CI 14.2-62.8%), and odds ratio of 0.18 (95% CI 0.05-0.61) for correcting errors at initial endoscopy.

CONCLUSIONS

Repeat endoscopy in colorectal cancer is superior to staging CT as a diagnostic tool for correcting localization-based errors at initial endoscopy.

Tattooing or not? A review of current practice and outcomes for laparoscopic colonic resection following endoscopy at a tertiary care centre

BACKGROUND

Because small colonic tumours may not be visualized or palpated during laparoscopy, location of the lesion must be identified before surgery. The aim of this study was to evaluate the effectiveness of the current recommendation of endoscopic tattooing of lesions prior to laparoscopic colonic resections.

METHODS

All consecutive patients who underwent elective laparoscopic resection for a colonic lesion at a single tertiary institution between 2013 and 2015 were identified for chart review.

RESULTS

In total, 224 patients underwent laparoscopic resection for a benign or malignant colonic lesion during the study period. All patients had a complete colonoscopy preoperatively. In all, 148 patients (66%) had their lesion tattooed at endoscopy. Most lesions were tattooed distally, but 15% were tattooed either proximally, both proximally and distally, or tattooed without specifying location as proximal or distal. Tattoo localization was accurate in 69% of cases. Tattooed lesions were not visible during surgery 21.5% of time; 2 cases were converted to open surgery to identify the lesion. Inaccuracy in endoscopic localization led to change in surgical plan in 16% of surgeries. In the nontattooed group, 1 case was converted to open surgery to localize the lesion, 3 required intraoperative colonoscopy and 1 had positive margins on final pathology.

CONCLUSION

To improve surgical planning, we recommend the practice of endoscopic tattooing of all colon lesions at a location just distal to the lesion using multiple injections to cover the circumference of the bowel wall.