To be thorough or tailored: influence of the arachnoid dissection range on the surgical outcomes of microvascular decompression for hemifacial spasm

BACKGROUND

As one of the most fundamental elements in exposure and decompression, the dissection of arachnoid has been rarely correlated with the surgical results in studies on Microvascular decompression (MVD) procedures for Hemifacial spasm (HFS).

MATERIALS AND METHODS

Patients' records of the HFS cases treated with MVD from January 2016 to December 2021 in our center was retrospectively reviewed. The video of the procedures was inspected thoroughly to evaluate the range of dissection of arachnoid. Four areas were defined in order to facilitate the evaluation of the dissection range. The correlation between the arachnoid dissection and the surgical outcomes were analyzed.

RESULTS

The arachnoid structures between the nineth cranial nerve and the seventh, eighth cranial nerves were dissected in all cases, other areas were entered based on different consideration. The rate of neurological complications of the extended dissection pattern group was higher than that of the standard pattern group (P < 0.05). The procedures in which the arachnoid structure above the vestibulocochlear nerve was dissected, led to more neurological complications (P < 0.05).

CONCLUSION

Thorough dissection as an initial aim for all cases was not recommended in MVD for HFS, arachnoid dissection should be tailored to achieving safety and effectiveness during the procedure.

The effect of subperichondrial dissection on nasal vascularity in septorhinoplasty operations

PURPOSE

Nasal vascularization runs above the superficial musculoaponeurotic system (SMAS). Perichondrium covers the lower and upper lateral cartilages. In this study, nasal vascularization was compared between subperichondrial and supraperichondrial dissection in closed septorhinoplasty.

METHODS

95 patients and 41 volunteers were included in this study. Supraperichondrial dissection was performed in 48 patients and subperichondrial dissection was performed in 47 patients. To measure blood stream, laser doppler flowmetry (LDF) was used and measurements were done preoperatively, on the postoperative first week; 3rd month and first year.

RESULTS

The nasal tip and dorsum measurements were similar between the preoperative and postoperative first year in both groups (p = 1.000). However, in the supraperichondrial dissection group, nasal tip measurements showed a significant increase between the preoperative and third postoperative months (p = 0.011). This increase was accompanied by an increase in the minimal blood stream (p = 0.014).

CONCLUSION

Both subperichondrial and supraperichondrial dissection techniques are physiological and result in fewer complications with minimal permanent vascular damage. We believe incision plays a critical role but keeping the perichondrium intact is important for short-term angiogenesis, where long-term results showed no difference in vascularization.

Prevalence and clinical significance of the muscle retracting sign during endoscopic submucosal dissection of large macronodular colorectal lesions (with videos)

BACKGROUND AND AIMS

The muscle retracting sign (MRS) can be present during endoscopic submucosal dissection (ESD) of macronodular colorectal lesions. The prevalence of MRS and its pathologic and clinical implications is unclear. This study evaluated the effect of MRS on the technical and clinical outcomes of ESD.

METHODS

All patients referred for ESD of protruding lesions or granular mixed lesions with >10 mm macronodule granular mixed laterally spreading tumors (LST-GMs) in 2 academic centers from January 2017 to October 2022 were prospectively included. Size of the macronodule was analyzed retrospectively. The primary outcome was the curative resection rate according to MRS status. Secondary outcomes were R0 resection, perforation, secondary surgery rate, and risk factors for MRS.

RESULTS

Of 694 lesions, 84 (12%) had MRS (MRS+). The curative resection rate was decreased by MRS (MRS+ 41.6% vs lesions without MRS [MRS-] 81.3%), whereas the perforation (MRS+ 22.6% vs MRS- 9.2%), submucosal cancer (MRS+ 34.9% vs MRS- 9.2%), and surgery (MRS+ 45.2% vs MRS- 6%) rates were increased. The R0 resection rate of MRS+ colonic lesions was lower than that of rectal lesions (53% vs 74.3%). In multivariate analysis, protruding lesions (odds ratio, 2.47; 95% confidence interval, 1.27-4.80) and macronodules >4 cm (odds ratio, 4.24; 95% confidence interval, 2.23-8.05) were risk factors for MRS.

CONCLUSIONS

MRS reduces oncologic outcomes and increases the perforation rate. Consequently, procedures in the colon should be stopped if MRS is detected, and those in the rectum should be continued due to the morbidity of alternative therapy.

Complete mesocolic excision for colon cancer: current status and controversies

According to Hohenberger's original description, complete mesocolic excision for colon cancer involves precise dissection of the avascular embryonic plane between the parietal retroperitoneum and visceral peritoneum of the mesocolon. This ensures mesocolic integrity, access to high ligation of the supplying vessels at their origin and an associated extended lymphadenectomy. Results from centres which have adopted this approach routinely have demonstrated that oncological outcomes can be improved by the rigorous implementation of established principles of cancer surgery. Meticulous anatomical dissection along embryonic planes is a well-established principle of precision cancer surgery used routinely by the specialist colorectal surgeon. Therefore, the real question concerns the need for true central vascular ligation and associated extended (D3) lymphadenectomy or otherwise, particularly along the superior mesenteric vessels when performing a right colectomy. Whether this approach results in improved overall or disease-free survival remains unclear and its role remains controversial particularly given the potential for significant morbidity associated with a more extensive central vascular dissection. Current literature is limited by considerable bias, as well as inconsistent and variable terminology, and the results of established randomized trials are awaited. As a result of the current state of equipoise, various national guidelines have disparate recommendations as to when complete mesocolic excision should be performed if at all. This article aims to review the rationale for and technical aspects of complete mesocolic excision, summarize available short and long term outcome data and address current controversies.

Educational stereoscopic representation of a step-by-step brain white fiber dissection according to Klingler's method

BACKGROUND

Understanding and teaching the three-dimensional architecture of the brain remains difficult because of the intricate arrangement of grey nuclei within white matter tracts. Although cortical area functions have been well studied, educational and three-dimensional descriptions of the organization of deep nuclei and white matter tracts are still missing.

OBJECTIVE

We propose herein a detailed step-by-step dissection of the lateral aspect of a left hemisphere using the Klingler method and provide high-quality stereoscopic views with the aim to help teach medical students or surgeons the three-dimensional anatomy of the brain.

METHODS

Three left hemispheres were extracted and prepared. Then, according to the Klingler method, dissections were carried out from the lateral aspect. Photographs were taken at each step and were modified to provide stereoscopic three-dimensional views.

RESULTS

Gray and white structures were described: cortex, claustrum, putamen, pallidum, caudate nucleus, amygdala; U-fibers, external and internal capsules, superior longitudinal fasciculus, frontal aslant fasciculus, uncinate fasciculus, inferior fronto-occipital fasciculus, inferior longitudinal fasciculus, corticospinal fasciculus, corona radiata, anterior commissure, and optic radiations.

CONCLUSION

This educational stereoscopic presentation of an expert dissection of brain white fibers and basal ganglia would be of value for theoretical or hands-on teaching of brain anatomy; labeling and stereoscopy could, moreover, improve the teaching, understanding, and memorizing of brain anatomy. In addition, this could be also used for the creation of a mental map by neurosurgeons for the preoperative planning of brain tumor surgery.

Endoscopic submucosal dissection assisted by adaptive traction: results of the first 54 procedures

BACKGROUND : Good submucosal exposure is key to successful endoscopic submucosal dissection (ESD) and can be achieved with various traction devices. Nevertheless, these devices have a fixed traction force that tends to decrease as the dissection progresses. In contrast, the ATRACT adaptive traction device increases traction during the procedure. METHODS : In this retrospective analysis of prospectively collected data (from a French database), we analyzed ESD procedures performed with the ATRACT device between April 2022 and October 2022. The device was used consecutively whenever possible. We collected details of lesion characteristics, procedural data, histologic outcomes, and clinical consequences for the patient. RESULTS : 54 resections performed in 52 patients by two experienced operators (46 procedures) and six novices (eight procedures) were analyzed. The ATRACT devices used were the ATRACT-2 (n = 21), the ATRACT 2 + 2 (n = 30), and the ATRACT-4 (n = 3). Four adverse events were observed: one perforation (1.9 %), which was closed endoscopically, and three delayed bleeding events (5.5 %). The R0 rate was 93 %, resulting in curative resection in 91 % of cases. CONCLUSION:  ESD using the ATRACT device is safe and effective in the colon and rectum, but can also be used to assist with procedures in the upper gastrointestinal tract. It may be particularly useful in difficult locations.

Direct Inside-Out Observation of Superficial White Matter Fasciculi in the Human Brain

Background: Recent methodological advances in the study of the cerebral white matter have left short association fibers relatively underexplored due to their compact and juxtacortical nature, which represent significant challenges for both post-mortem post-cortex removal dissection and magnetic resonance-based diffusion imaging. Objective: To introduce a novel inside-out post-mortem fiber dissection technique to assess short association fiber anatomy. Methods: Six cerebral specimens were obtained from a body donation program and underwent fixation in formalin. Following two freezing and thawing cycles, a standardized protocol involving peeling fibers from deep structures towards the cortex was developed. Results: The inside-out technique effectively exposed the superficial white matter. The procedure revealed distinguishable intergyral fibers, demonstrating their dissectability and enabling the identification of their orientation. The assessment of layer thickness was possible through direct observation and ex vivo morphological magnetic resonance imaging. Conclusion: The inside-out fiber technique effectively demonstrates intergyral association fibers in the post-mortem human brain. It adds to the neuroscience armamentarium, overcoming methodological obstacles and offering an anatomical substrate essential for neural circuit modeling and the evaluation of neuroimaging congruence. Impact statement The inside-out fiber dissection technique enables a totally new perception of cerebral connectivity as the observer navigates inside the parenchyma and looks toward the cerebral surface with the subcortical white matter and the cortical mantle in place. This approach has proven very effective for exposing intergyral association fibers, which have shown to be much more distinguishable from an inner perspective. It gave rise to unprecedented images of the human superficial white matter and allowed, for the first time, direct observation of this vast mantle of fascicles on entire cerebral hemisphere aspects.

Revealing the confusion of the evolution of the term sagittal stratum. Historical overview and systematic literature review

The fiber dissection technique is one of the earliest methods used to demonstrate the internal structures of the brain, but until the development of fiber tractography, most neuroanatomy studies were related to the cerebral cortex and less attention was given to the white matter. During the historical evolution of white matter dissection, debates have arisen about tissue preservation methods, dissection methodology, nomenclature, and efforts to adopt findings from primates to the human brain. Since its first description, the sagittal stratum has been one of the white matter structures subject to controversy and has not been sufficiently considered in the literature. With recent functional studies suggesting potential functions of the sagittal stratum, the importance of attaining a precise understanding of this structure and its constituent fiber tracts is further highlighted. This study revisits the historical background of white matter dissection, unveils the early synonymous descriptions of the sagittal stratum, and provides a systematic review of the current literature. Through evaluation of the historical statements about the sagittal stratum, we provide an understanding of the divergence and explain the reasons for the ambiguity. We believe that acquiring such an understanding will lead to further investigations on this subject, which has the potential to benefit in addressing various neuropsychiatric conditions, maintaining functional connectivity, and optimizing surgical outcomes.

Extracapsular dissection versus total excision for benign submandibular gland tumors

INTRODUCTION

Benign submandibular gland tumors pose challenges in balancing treatment effectiveness and preserving gland function. This study aimed to compare gland-preserving surgery, extracapsular dissection (ECD), with total excision in managing these tumors, focusing on function preservation and recurrence rate.

METHODS

Fifty consecutive patients with treatment-naïve benign submandibular gland tumors were alternatively allocated to receive ECD (n = 25) or total excision (n = 25) without randomization procedures. Intraoperative findings, postsurgical complications, subjective satisfaction, and gland function were assessed. Follow-up data were collected for a median duration of 55 months (24-80 months) to monitor recurrences.

RESULTS

ECD demonstrated significant advantages, including shorter operation time, reduced bleeding, and preservation of the facial artery and vein (P < 0.05). Both groups exhibited acceptable postsurgical pain and taste sensations. Complications were minimal and similar between the two groups. ECD resulted in superior facial contour satisfaction (P = 0.030) and preserved gland function, as evidenced by salivary scintigraphy. No recurrences were observed in either group during the follow-up period.

CONCLUSIONS

ECD is a practical approach for benign submandibular gland tumors, offering favorable functional outcomes, reduced surgical morbidity, shorter operation times, and improved cosmetic results.

A novel miniature flexible robotic system for endoscopic mucosal dissection: an animal experimental study

Endoscopic submucosal dissection (ESD) is a standard treatment for early gastrointestinal cancer due to its higher rate of en-bloc resection and lower recurrence rate. However, the technical challenges lead to long learning curve and high risks of adverse events. A gastrointestinal flexible robotic-tool system (GIFTS) was proposed to reduce the difficulty and shorten the learning curve of novices. This is an animal study to evaluate the feasibility of GIFTS in ESD. The GIFTS provides a total of 13 degrees of freedom within 10 mm in diameter and variable stiffness function to achieve endoscopic intervention and submucosal dissection with the cooperation of two flexible robotic instruments. One esophageal and four colorectal ESDs in five porcine models were performed. In all five ESD procedures, the GIFTS was successfully intubated and submucosal dissection was completed without perforation or significant bleeding, and there was no system fault. The mean operative time was 99 min, and the mean size of the specimen was 151 mm2. The fifth experiment showed significantly better results than the first one. In vivo animal experiments confirmed the feasibility of GIFTS in performing ESD. The control of GIFTS is friendly to inexperienced beginners, which will help reduce the technical challenges of ESD and shorten the learning curve of endoscopists.

Endoscopic Resection of Early Luminal Cancer

Gastrointestinal cancers can have severe consequences if diagnosed at a late stage but can be cured when detected and resected at an early stage. In recent years, the significance of endoscopic screening for gastrointestinal cancers has been established, leading to the identification of early-stage cancers and precancerous lesions. Consequently, endoscopic removal of gastrointestinal tumors has emerged as an effective means of cancer treatment and prevention. This article delves into the indications, techniques, and safety measures associated with endoscopic resection of early-stage luminal cancer within the gastrointestinal tract.

Novel quantitative assessment indicators for efficiency and precision of endoscopic submucosal dissection in animal training models by analyzing an electrical surgical unit

OBJECTIVES

Although endoscopic submucosal dissection (ESD) training is important, quantitative assessments have not been established. This study aimed to explore a novel quantitative assessment system by analyzing an electrical surgical unit (ESU).

METHODS

This was an ex vivo study. Step one: to identify the novel efficiency indicators, 20 endoscopists performed one ESD each, and we analyzed correlations between their resection speed and electrical status. Step two: to identify the novel precision indicators, three experts and three novices performed one ESD each, and we compared the stability of the electrical status. Step three: three novices in step two performed 19 additional ESDs, and we analyzed the learning curve using novel indicators.

RESULTS

Step one: the percentage of total activation time (AT) of ESU in the procedure time (β coefficient, 0.80; P < 0.01) and AT required for submucosal dissection (β coefficient, -0.57; P < 0.01) were significantly correlated with the resection speed. Step two: coefficient of variation of the AT per one pulse (0.16 [range, 0.13-0.17] vs. 0.26 [range, 0.20-0.41], P = 0.049) and coefficient of variation of the peak electric power per pulse during mucosal incision (0.14 [range, 0.080-0.15] vs. 0.25 [range, 0.24-0.28], P = 0.049) were significantly lower in the experts than in the novices. Regarding the learning curve, the percentage of total AT of ESU in the procedure time and AT required for submucosal dissection had a trend of improvement.

CONCLUSION

Novel indicators identified by analyzing ESU enable quantitative assessment for endoscopist's skill.

Supporting collaborative dissection through the development of an online wiki positively impacts the learning of veterinary anatomy

An innovative series of dissections of the canine abdomen was created to facilitate social distancing in the dissection room following COVID-19 restrictions imposed in the UK. In groups of six, first-year veterinary students took turns dissecting selected parts of the canine abdomen while maintaining social distancing and documenting their work with video and photographs. Here, students learned about the canine abdominal anatomy by dissecting, recording the dissections of others in their group, and compiling the recorded material into a collaborative electronic media portfolio (Wiki). An online formative multiple-choice test was created to test students' knowledge of the canine abdominal anatomy. The result analysis showed that although students achieved the learning outcomes only by studying the Wiki, they had better performance in the anatomical areas where they learned through the dissection (p < 0.05). Student performance was very similar in the areas in which they were present in the dissection room and participated in recording the dissection compared with the areas that they effectively dissected (p > 0.05). A qualitative thematic analysis was developed to understand students' opinions via their feedback on this dissection approach. Our results showed that student collaboration and the development of practical skills were the most valued aspects of this dissection teaching initiative. Moreover, these results show that developing a group Wiki has a positive impact on student achievement of learning objectives, with a practical hands-on dissection being fundamental for the optimal learning of the canine abdominal anatomy.

Hybrid endoscopic submucosal dissection as a salvage option for difficult colorectal conventional endoscopic submucosal dissection

BACKGROUND

When total submucosal dissection is difficult to achieve during conventional colorectal endoscopic submucosal dissection (C-ESD), the lesion can be resected by final snaring through salvage hybrid ESD (SH-ESD). This study aimed to examine the outcomes of SH-ESD and identify its indications that could achieve en bloc resection.

METHODS

We recruited 1039 consecutive patients with colorectal lesions that underwent ESD at Hiroshima University Hospital between January 2015 and December 2020. C-ESD was attempted thoroughly in 924 lesions (C-ESD group, including 9 lesions in which ESD was discontinued), and SH-ESD was performed owing to some difficulties in 115 lesions (SH-ESD group). Risk factors for incomplete resection by SH-ESD and ESD discontinuation were evaluated using multivariate analysis. The outcomes were compared between cases with remaining undissected submucosa of < 20 mm in diameter in the SH-ESD and C-ESD groups, using propensity score matching.

RESULTS

Multivariate analysis revealed that a procedure time > 80 min and remaining undissected submucosa ≥ 20 mm in diameter were significant risk factors for incomplete resection after SH-ESD and ESD discontinuation. By propensity score matching analysis, procedure time was significantly shorter in the SH-ESD group with remaining undissected submucosa < 20 mm in diameter than in the C-ESD group (71 min vs. 90 min, p = 0.0053), although no significant difference was found in the en bloc resection rate (94% vs. 87%, p = 0.0914).

CONCLUSION

SH-ESD can be an alternative surgical method when conventional ESD is difficult to continue in cases in which the remaining undissected submucosa is < 20 mm in diameter.

Endoscopic intermuscular dissection (EID) for removing early rectal cancers and benign fibrotic rectal lesions

In the current era of screening colonoscopy and increasing incidence of early rectal cancer, interventional endoscopy moves toward resections in deeper planes than the submucosal layer. Several reports support the use of endoscopic intermuscular dissection (EID) instead of endoscopic submucosal dissection (ESD) for the removal of deeply invasive rectal submucosal cancers. The resection plane into the intermuscular space, the space between the longitudinal (external) and circular (internal) muscle layer, allows radical removal of rectal invasive submucosal cancers. Furthermore, the technique offers the potential for dissection of scarred and severe fibrotic lesions in the rectum by cutting deeper and performing a partial myectomy avoiding the narrow submucosal space. We present 23 cases of EIDs both for deeply invasive rectal cancers and benign rectal lesions. This is the first report in the literature of EID resections for malignant and benign disease, including cases of severely fibrotic rectal lesions.

Microsurgical and fiber tract anatomy of the interthalamic adhesion

OBJECTIVE

The authors of this study aimed to define the microanatomy of the interthalamic adhesion (ITA) using microfiber dissection, magnetic resonance (MR) tractography, and histological analysis.

METHODS

Sagittal, coronal, and axial MR images from 160 healthy individuals 2-82 years of age were examined. The relationships between age range and ITA morphology as well as between gender and ITA morphology were evaluated statistically. Among these 160 individuals, 100 who had undergone MR tractography were examined. In this group, the presence of fiber tracts in the ITA and the relationship with ITA morphological types were examined. Thirty formalin-fixed human cadaveric brains were also examined endoscopically, and 6 hemispheres were dissected from the medial to lateral and superior to inferior directions under the microscope. Sections taken from one of the brains with an ITA type 2 with both thalami were examined histologically. Anti-neurofilament antibody was used in the histological examination.

RESULTS

Four morphological types of ITA were observed. Type 1 had an adhesion/adherent appearance, type 2 had a bridge/commissure appearance, type 3 showed no adhesion, and type 4 had a double bridge. Tractographic examination revealed that 28% had no fiber tract transition in the ITA, 21% had a significant transition, and 51% had an indistinct transition. Statistically, the presence of the ITA was significantly higher in the pediatric (age) and female (gender) groups. In specimens with ITAs of a bridge/commissure appearance (type 2), fiber tracts showed clear transitions between thalami. In type 1 (adherent/adhesive appearance), fiber tracts were observed within the ITA, but a reciprocal transition was unclear. Dissection showed that these fiber tracts in the ITA reach the nucleus accumbens, caudate nucleus, and frontoorbital region anteriorly and the lateral habenula and posterior commissure posteriorly. Some fibers also joined the ansa peduncularis. In histological studies, axonal fibers moving in the ITA were observed with anti-neurofilament antibody staining.

CONCLUSIONS

This is the first study to demonstrate fiber tracts of the ITA through fiber dissection and transillumination techniques as well as radiological and histological study. Statistical data were obtained by comparing the morphological group with age and gender groups. The anatomy of this structure, which has been neglected for many years, was reexamined. This study showed that the ITA has fibers connecting different parts of the brain, in contrast to previous studies suggesting that it was a simple massa.

Inframesocolic main pancreatic vessels-first approach for minimally invasive radical antegrade modular pancreaticosplenectomy (RAMPS): technical description and first experience

Radical modular antegrade pancreaticosplenectomy (RAMPS) improves posterior tumor-free margins during resections of pancreatic neoplasia involving the body or tail. However, minimally invasive RAMPS is technically challenging and has been reported seldom. We present for the first time a minimally invasive RAMPS technique with an innovative approach providing early dissection and control of the main peripancreatic vessels from an inframesocolic embryonal window, suitable for laparoscopy and robotics. Minimally invasive RAMPS with inframesocolic main pancreatic vessels-first approach was performed at the Tricase Hospital (Italy) from May 2017 to April 2022 in 11 consecutive patients with neoplastic lesions of the pancreas (8 laparoscopic RAMPS and 3 robotic RAMPS). Among the laparoscopic cases, 1 included a portal vein tangential resection and 1 a celiac artery resection (modified Appleby procedure). There were no conversions, no Clavien-Dindo complications > 2, all resections' margins were tumor free, and no 90-day mortality.

Is colorectal endoscopic submucosal dissection safe and effective for 15-19-mm tumors?

PURPOSE

The outcomes of colorectal endoscopic submucosal dissection (ESD) in 15-19-mm tumors are unclear. This study compared the effectiveness and safety of colorectal ESD for 15-19-mm tumors and tumors exceeding that size.

METHODS

From August 2018 to December 2020, 213 cases of colorectal tumors removed by colorectal ESD at a tertiary hospital were enrolled in this study. The cases were divided into two groups according to the pathologically measured size of the resected lesion: an intermediate group (15-19 mm, n = 62) and a large group (≥ 20 mm, n = 151). The en bloc resection rate, complete resection rate, and complications were investigated retrospectively.

RESULTS

The en bloc resection rate was significantly higher in the intermediate than large group (100% vs. 94%, p = 0.049), and the mean total procedure time was shorter in the intermediate than large group (29.2 [Formula: see text] 12.6 vs. 48.4 [Formula: see text] 28.8 min, p < 0.001). However, the mean procedure speed was significantly lower in the intermediate than large group (0.25 [Formula: see text] 0.10 vs. 0.28 [Formula: see text] 0.11 cm2/min, p = 0.031). The complete resection rate, post-procedural bleeding, and perforation rate were not significantly different between the two groups. In multivariate analyses, the total procedure time and mean procedure speed were significantly associated with lesion size.

CONCLUSION

Colorectal ESD of 15-19-mm lesions is effective, and has a shorter procedure time and higher en bloc resection rate than the same procedure for larger lesions.

First pilot trial of colorectal ESD guided by a new magnetic anchor for ease of placement

BACKGROUND

In recent years, studies have demonstrated that magnetic anchor-guided endoscopic submucosal dissection (MAG-ESD) is feasible and safe and may facilitate the treatment of all difficult lesions. However, the major problem with MAG-ESD is the inability to deliver the magnetic anchor to the gastrointestinal tract without withdrawal or reinsertion of the endoscope. Therefore, our team developed a magnetic anchor that could be easily inserted through the biopsy channel, facilitating ESD traction and evaluated its effectiveness and safety.

METHODS

The study was conducted between October 2020 and June 2021 at The Second Affiliated Hospital of Harbin Medical University, China. One hundred and twelve patients with colorectal tumors treated with ESD were divided into two groups for historical control comparison. A channel-placed magnetic anchor (CPMAG) group and a control group consisting of patients who had conventional ESD without adjuvant traction. The rate of en bloc resection and resection with tumor-free lateral/basal margins (R0 resection), dissection speeds, procedure time, intraoperative bleeding and perforation complications, and postoperative follow-up were compared between the two groups, so as to evaluate the clinical effect and safety of the new magnetic anchor.

RESULTS

The en bloc resection and R0 resection rate with CPMAG-ESD were slightly higher than with conventional ESD but this was not statistically significant. The median dissection speeds with CPMAG-ESD were higher than with conventional ESD, but the difference was not statistically significant. Intraoperative bleeding and postoperative complications with the CPMAG-ESD were less than with conventional ESD, but this was not statistically significant. The median operating time was shorter with CPMAG- ESD than with conventional ESD (24.5 min [range 15.8-66.5 min] vs 39 min [range 29-58 min], p = 0.024), and this difference was statistically significant.

CONCLUSIONS

The new magnetic anchor-guided ESD technique appears to be a feasible and safe method for treating early colorectal tumors with en bloc resection, with improvement of the submucosal visual field, and less adverse events.

Multitraction with rubber bands and surgical silk as a method to facilitate endoscopic submucosal dissection

We propose this variant of the clip technique as a method that assist traction during endoscopic submucosal dissection (ESD): traction on the mucosa plane using an hemoclip carrying a surgical silk and three rubber bands, before the incision, to allow easier access to the submucosa space. We propose this variant with the intention of facilitating access to ESD quickly and safely for beginners.

Current Status of Diagnosis and Treatment of Colorectal Cancer in Asian Countries: A Questionnaire Survey

INTRODUCTION

Diagnostic and therapeutic methods for colorectal cancer (CRC) have advanced; however, they may be inaccessible worldwide, and their widespread use is challenging. This questionnaire survey investigates the current status of diagnosis and treatment of early-stage CRC in Asian countries.

METHODS

Responses to the questionnaire were obtained from 213 doctors at different institutions in 8 countries and regions. The questionnaire consisted of 39 questions on the following four topics: noninvasive diagnosis other than endoscopy (6 questions), diagnosis by magnification and image-enhanced endoscopy (IEE) including artificial intelligence (AI) (10 questions), endoscopic submucosal dissection (ESD), proper use among other therapeutic methods (11 questions), and pathologic diagnosis and surveillance (12 questions).

RESULTS

Although 101 of 213 respondents were affiliated with academic hospitals, there were disparities among countries and regions in the dissemination of advanced technologies, such as IEE, AI, and ESD. The NICE classification is widely used for the diagnosis of colorectal tumors using IEE, while the JNET classification with magnification was used in countries such as Japan (65/70, 92.9%) and China (16/22, 72.7%). Of the 211 respondents, 208 (98.6%) assumed that en bloc resection should be achieved for carcinomas, and 180 of 212 (84.9%) believed that ESD was the most suitable in cases with a diameter larger than 2 cm. However, colorectal ESD is not widespread in countries such as Thailand, the Philippines, and Indonesia.

CONCLUSION

The promotion of advanced technologies and education should be continual to enable more people to benefit from them.

Anatomical study of the distal course of the posterior tibial artery: A cadaver study

OBJECTIVE

This study aimed to describe the course, branches, and variances of the posterior tibial artery, which provides the arterial supply of the plantar surface of the foot, starting from the tarsal tunnel level to provide descriptive information for all surgical interventions, diagnostic radiological procedures, and promising endovascular therapies in the tarsal region.

METHODS

In this study, a dissection of 48 feet was performed on 25 formalin-fixed cadavers (19 males and 6 females). Surgical instruments and a digital caliper were used for dissection and measurements, and the critical structures were recorded by a Canon 250D camera to be illustrated later.

RESULTS

All parameters were significantly longer in male cadavers compared to females. According to the correlation analysis, while there was a significant and robust correlation between the axial line and pternion-deep plantar arch (R=.830, P .05), a moderate correlation was found between the axial line and sphyrion-bifurcation (R=.575; P < .05), axial line and deep plantar arch-2nd interdigital commissure (R=.457; P < .05), and sphyrion-bifurcation and pternion-deep plantar arch (R=.480; P < .05). Variation in any branch of the posterior tibial artery was observed in 27 of the 48 studied sides.

CONCLUSION

In our study, the branching and variability of posterior tibial artery on the plantar surface of the foot were described in detail with the determined parameters. In conditions that cause tissue and function loss and require reconstruction, such as diabetes mellitus and atherosclerosis, the most critical factor in increasing treatment success is a better understanding of the region's anatomy.

Targeted labeling with tissue marking dyes guided by magnifying endoscopy of endoscopic submucosal dissection specimen improves the accuracy of endoscopic and histopathological diagnosis of early gastric cancer: a before–after study

BACKGROUND

Although histopathological evaluation after endoscopic submucosal dissection (ESD) is critical to assess the accuracy of endoscopic diagnosis, it is still challenging to perform precise endoscopic to pathological evaluation. We evaluated the importance of tissue marking dye (TMD)-targeted marking for post-ESD specimen guided by magnificent endoscope on histopathological accuracy and endoscopic-to-histopathological reconstruction.

STUDY DESIGN

A total of 81 specimens resected by ESD [43 without TMD marking (N-TMD group), and 38 specimens with TMD-targeted cancerous areas marking guided by post-procedural magnifying endoscopy on resected specimens (TMD group)] between January 31, 2019, and January 31, 2022 at the Renmin Hospital of Wuhan University were included in the study. The baseline characteristics of patients, discrepancies between endoscopic and histopathological diagnosis, and the impact of TMD on histopathological diagnosis and reconstruction were analyzed.

RESULTS

Discrepancies between endoscopic (pre-ESD) and histopathological (post-ESD) diagnosis increased significantly in TMD group (68.4% (26/38) for tumor areas, 26.3% (10/38) for tumor margins, and 26.3% (10/38) for tumor differentiations) when compared with N-TMD group (p < 0.0001). Deeper sections were achieved in all TMD-marked resected lesions and 27.9% (12/43) lesions in the N-TMD group (p < 0.001). More pathological evaluations in TMD group were changed from curative resection to non-curative resection [6/38(15.8%) vs 1/43(2.3%)] compared with N-TMD group (p < 0.0001). TMD-targeted marking also improved the efficiency of histopathological reconstruction on pre-procedural endoscopic images and benefit endoscopists training.

CONCLUSION

TMD-targeted labeling on resected specimens could improve precise endoscopic-to-pathological diagnosis, reconstruction by point-to-point marking and benefit endoscopists training.

Clinical outcomes of endoscopic submucosal dissection for colorectal neoplasms: A single-center experience in Southern Taiwan

Background and aims

Endoscopic submucosal dissection (ESD) as an advanced endoscopic procedure can be considered for the removal of colorectal lesions with high suspicion of limited submucosal invasion or cannot be optimally removed by snare-based techniques. We aimed to analyze the clinical outcomes of ESD for colorectal neoplasms in our hospital.

Methods

We retrospectively enrolled 230 patients with 244 colorectal neoplasms who received ESD procedures from April 2012 to October 2020 at Kaohsiung Chang Gung Memorial Hospital. Clinicopathological data were collected by chart review. We also recorded ESD-related complications and clinical outcomes.

Results

The average age was 64 years old, with a mean follow-up time of 22.59 months. There was a loss of follow-up in 34 lesions. Most lesions were lateral spreading tumors of the non-granular type. The average ESD time was 51.9 minutes. Nine cases (3.7%) had procedure-related complications, including two intra-procedure perforations (0.8%) and seven delayed bleeding (2.9%) without procedure-related mortality. 241 lesions (98.8%) achieved en-bloc resection, while 207 lesions (84.8%) achieved R0 resection. Most lesions were tubulo-(villous) adenoma. Malignancy included 35 adenocarcinomas and 5 neuroendocrine tumors. No local recurrence was developed during follow-up. Multivariate analysis for long ESD time revealed significance in size ≥ 10 cm² and endoscopist’s experience < 3 years. Pre-ESD endoscopic ultrasound revealed good prediction in discrimination of mucosal (sensitivity: 0.90) and submucosal lesion (specificity: 0.67).

Conclusions

ESD for colorectal neoplasms is an effective and safe technique. Size ≥ 10 cm² and endoscopist’s experience < 3 years were significantly associated with long procedure time. Pre-ESD EUS provided a good prediction for colorectal neoplasms in invasion depth.

Endoscopic submucosal dissection for proximal duodenal subepithelial lesions: a retrospective cohort study

BACKGROUND AND AIM

Endoscopic submucosal dissection (ESD) has been used to remove subepithelial lesions (SELs) in recent years; however, duodenal ESD is associated with high rates of immediate or delayed bleeding and perforation. Whether ESD can be recommended for the treatment of duodenal SELs remains controversial. Therefore, we evaluated the efficacy and safety of ESD for duodenal SELs.

METHODS

We conducted a retrospective cohort study in 62 patients (62 lesions) who underwent ESD for duodenal SELs between January 2012 and December 2020. The therapeutic outcomes from ESD for duodenal SELs and procedure-related complications were analyzed.

RESULTS

En bloc resection and complete resection rates associated with duodenal ESD were 90.3% and 100%, respectively; four patients had a positive microscopic margin on pathologic examination. The median procedure time was 45 min (range 20-106 min). During the procedure, two patients received emergency surgery for uncontrolled bleeding and perforation, respectively. After the procedure, delayed bleeding occurred in three patients (4.8%), which was successfully managed by clipping, and delayed perforation occurred in two patients (3.2%) and needed emergency surgery. Risk factors related to complications were analyzed. Lesion size was found to be significantly associated with the complications (P = 0.028). No recurrences were detected, and no distant metastasis was observed in any patient during a median follow-up period of 45.5 months (range, 6-103 months).

CONCLUSION

Duodenal ESD is relatively safe and feasible for duodenal SELs, especially for lesions no more than 2 cm in size.

A Comparison of Tissue Dissection Techniques for Diagnostic, Prognostic, and Theragnostic Analysis of Human Disease

Histopathology has historically been the critical technique for the diagnosis and treatment of human disease. Today, genomics, transcriptomics, and proteomics from specific cells, rather than bulk tissue, have become key to understanding underlying disease mechanisms and rendering useful diagnostic information. Extraction of desired analytes, i.e., nucleic acids or proteins, from easily accessible formalin-fixed paraffin-embedded tissues allows for clinically relevant activities, such as sequencing biomarker mutations or typing amyloidogenic proteins. Genetic profiling has become routine for cancers as varied as non-small cell lung cancer and prostatic carcinoma. The five main tissue dissection techniques that have been developed thus far include: bulk scraping, manual macrodissection, manual microdissection, laser-capture microdissection, and expression microdissection. In this review, we discuss the importance of tissue dissection in clinical practice and research, the basic methods, applications, as well as some advantages and disadvantages for each modality.

An Innovation in the Technique of Recipient Hepatectomy in Living Donor Liver Transplantation

Recipient hepatectomy is a challenging surgical procedure. Coagulopathy, multiple collaterals, and dense adhesions secondary to previous spontaneous bacterial peritonitis in cirrhotics are the major contributing factors. However, the appropriate recipient hepatectomy technique can limit the massive blood loss and minimize the operative time. The hepatoduodenal dissection has a key role in recipient hepatectomy. The hilar structures of partial graft in live donor liver transplantation (LDLT) usually have a short length and a small caliber. The concerning task in LDLT recipient hepatectomy is to preserve the integrity, quality, and adequacy of hilar structures for successful implantation. The high hilar dissection technique is usually practiced for getting the adequate length of hilar structures. However, the problems with high hilar dissection inducted the authors to tailor the technique over time. In this report, a modified technique of recipient hepatectomy characterised by the artery-first approach is described. This technique is good in terms of preventing arterial dissection and minimising the anhepatic phase. Key Words: Recipient hepatectomy, Hepatoduodenal dissection, Liver transplantation, Technique.

Early gastric cancer presenting as a typical submucosal tumor cured by endoscopic submucosal dissection: A case report

BACKGROUND

Submucosal tumor (SMT)-like gastric cancer is rare, and almost all cases undergo curative surgical treatment because the submucosal layer is usually deeply invaded by tumor cells or because histopathologic types of SMT-like gastric cancer are undifferentiated or poorly differentiated. No report has been issued on an SMT-like gastric cancer cured by endoscopic resection alone or on changes in the endoscopic features of this type of tumor over several years.

CASE SUMMARY

We describe an exceptional case of a 53-year-old male with a 1.5 cm-sized SMT-like lesion covered by normal-appearing mucosa discovered by esophagogastroduodenoscopy (EGD) at the gastric antrum. Endoscopic ultrasound (EUS) visualized a homogeneous, well-circumscribed hypoechogenic lesion arising from the second sonographic layer with associated subtle obliteration of the third sonographic layer. Initial endoscopic biopsy was negative for neoplasm. The patient refused to undergo an invasive procedure and was subsequently lost to follow-up. Three years after initial detection, EGD revealed the lesion had become markedly erythematous, and at 4 years after initial EGD it had increased in size to 1.8 cm and developed a central ulcer and a heterogeneous EUS echo. Finally, endoscopic submucosal dissection (ESD) was performed, and histopathologic examination revealed a moderately differentiated adenocarcinoma had minutely invaded the submucosal layer (invasion depth 169 μm) but without lymphovascular invasion and with negative resection margins. Fortunately, no additional surgical treatment was required. He has been followed for 4 years after ESD without any evidence of local or distant recurrence.

CONCLUSION

This report describes an extremely rare case of early gastric cancer presenting as SMT that was cured by ESD after a treatment delay of 4 years and the endoscopic changes that occurred during this period. The report highlights the importance of considering the possibility of gastric cancer when SMT is encountered in clinical practice.

New Applications for Submucosal Tunneling in Third Space Endoscopy: A Comprehensive Review

Third space endoscopy (TSE), a type of natural orifice transluminal endoscopic surgery, was first introduced a decade ago, and since then, has revolutionized the field of therapeutic endoscopy. TSE involves tunneling into the submucosal space between the intestinal mucosa and the muscularis propria. By accessing this "third space," endoscopists can perform minimally invasive myotomies, resections, and dissections while maintaining the mucosa and preventing full-thickness perforation. TSE procedures can be used to treat motility disorders as well as neoplasms throughout the gastrointestinal tract, which were traditionally conditions that would require open or laparoscopic surgery. The main TSE procedures include peroral endoscopic myotomy, gastric peroral endoscopic myotomy, Zenker peroral endoscopic myotomy, submucosal tunneling for endoscopic resection, endoscopic submucosal tunnel dissection, peroral endoscopic tunneling for restoration of the esophagus, and per-rectal endoscopic myotomy. Some of those procedures have now been accepted as viable alternative to surgical techniques due to their limited invasiveness, safety and cost. This review will explore the different techniques recently added to our arsenal while describing their potential efficacy and limitations.

Training program using a traction device improves trainees' learning curve of colorectal endoscopic submucosal dissection

BACKGROUND

Colorectal endoscopic submucosal dissection (ESD) requires advanced endoscopic skill. For safer and more reliable ESD implementation, various traction devices have been developed in recent years. The purpose of this research was to evaluate whether an ESD training program using a traction device (TD) would contribute to the improvement of trainees' skill acquisition.

METHODS

The differences in treatment outcomes and learning curves by the training program were compared before and after the introduction of TD (control group: January 2014 to March 2016; TD group: April 2016 to June 2018).

RESULTS

A total of 316 patients were included in the analysis (TD group: 202 cases; control group: 114 cases). The number of cases required to achieve proficiency in ESD techniques was 10 in the TD group and 21 in the control group. Compared to the control group, the TD group had a significant advantage in ESD self-completion rate (73.8% vs. 58.8%), dissection speed (19.5 mm²/min vs. 15.9 mm²/min), en bloc resection rate (100% vs. 90%), and R0 resection rate (96% vs. 83%).

CONCLUSIONS

The rate of colorectal ESD self-completion by trainees improved immediately after the start of the training program using a traction device compared to the conventional method, and the dissection speed tended to increase linearly with ESD experience. We believe that ESD training using a traction device will help ESD techniques to be performed safely and reliably among trainees.

Factors for conversion risk of colorectal endoscopic submucosal dissection: a multicenter study

BACKGROUND

Endoscopic submucosal dissection (ESD) has become a widely accepted treatment method for colorectal tumors; however, there are some persistent problems. This multi-center study aimed to characterize the risk factors for incomplete resection and perforation in standardized colorectal ESD procedures.

METHODS

This study included 2423 consecutive patients who underwent ESD for 2592 colorectal tumors between August 2013 and December 2018 at 11 institutions (1 academic hospital and 10 affiliated hospitals) from the Hiroshima GI Endoscopy Research Group. We evaluated the risk factors for interruption, piecemeal resection, and perforation of standardized colorectal ESD in relation to clinicopathologic and endoscopic characteristics.

RESULTS

The incidences of interruption, piecemeal resection, and perforation were 0.7%, 2.9%, and 3.0%, respectively. Multivariate analysis identified the following risk factors for interruption: perforation during the procedure, deep submucosal invasion (> 1000 μm), poor scope operability, and severe submucosal fibrosis. The risk factors for piecemeal resection included poor scope operability, severe submucosal fibrosis, and procedure time (≥ 85 min). The risk factors for perforation during the procedure were severe submucosal fibrosis, poor scope operability, procedure time (≥ 85 min), and tumor size (≥ 40 mm). Independent risk factors for severe submucosal fibrosis included a history of biopsy and lesions located on the fold or flexure.

CONCLUSIONS

Severe submucosal fibrosis and poor scope operability are the common risk factors for interruption, piecemeal resection, and perforation in standardized colorectal ESD.

[Research Progress in Delayed Bleeding after Endoscopic Submucosal Dissection of Early-Stage Gastrointestinal Cancer]

Endoscopic submucosal dissection (ESD) has been widely used in the clinical treatment of early-stage and precancerous lesions of the digestive tract. Compared with traditional open surgery, the procedure has a number of advantages, including low postprocedural recurrence rate, the location and scope of lesions not posing much restrictions on the procedure, and quick patients recovery afterwards. The procedure has hence become one of the minimally-invasive procedures commonly performed with gastrointestinal endoscope. However, due to the influence of various factors, complications such as intraoperative and postoperative bleeding, perforation, electrocoagulation syndrome and lumen stenosis may occur. Delayed postoperative bleeding, in particular, may induce cardiovascular and other related diseases due to the insidious nature of its onset, resulting in serious consequences. It is critically important for the further development of ESD that we should acquire thorough understanding and mastery of the relevant influencing factors and preventive measures of delayed bleeding after ESD of early-stage gastrointestinal cancer. We herein summarized and discussed the latest research findings in the preventative and treatment measures.

A colonoscopic overtube system that creates a 'therapeutic zone' and permits retraction facilitates endoscopic submucosal dissection, was associated with fewer deep bowel wall injuries and instrument exchanges, and required less lifting solution vs classic endoscopic submucosal dissection in an ex vivo bovine model

INTRODUCTION

Endoscopic submucosal dissection (ESD) is the 'gold standard' for large flat polyps; nevertheless, the rate of adoption in the USA is low. In ESD, the polyp is 'surgically' detached with a needle knife after a submucosal lift; gravity and the dissection cap are used for retraction. ESD would be easier if active retraction were possible. In an ex vivo bovine colon model, this study assessed an overtube system (Boston Scientific ORISE Tissue Retraction System, TRS) that permits retraction and creates 'an operative field' for removal of rectal/sigmoid lesions.

METHOD

Classic ESD (C-ESD) was compared to TRS-facilitated ESD (TRS-ESD). Cleaned/preserved bovine large bowel was used, and two 2-cm 'lesions'/colon were branded onto the mucosal surface 25 and 35 cm from the anus. Submucosal saline lifts were made using a thin catheter and a standard needle knife. We tracked case length, number of instrument exchanges (to refresh lift), the volume of lift solution, the fullness of resection, and deep muscle injuries.

RESULTS

Fifty ESDs were carried out in 25 colons (25 C-ESD, 25 TRS-ESD). Complete resections were noted in all cases. The TRS method required fewer instrument exchanges (median 5) vs C-ESD (median 9, p < 0.0001) and less lift solution (median 39 ml) than the C-ESD cases (median 55 ml, p = 0.0003). TRS-ESD was associated with fewer deep muscle injuries (median 2) than C-ESD (median 3, p = 0.0191). Finally, the TRS group's median case length (34.5 min) was shorter than that of C-ESD (41 min, p = 0.0543).

CONCLUSION

The TRS system provides retraction and facilitates ESD regarding the number of lift injections, the volume of lift solution needed, and avoidance of muscle injuries. Of note, there is an apparent TRS learning curve, and the device mandates a distal-to-proximal approach and initial 360 degree mucosal incision. Further study is warranted.

Gland-preserving surgery of benign parotid tumours via postauricular sulcus incision: Is it safe and effective with the scarless incision?

Gland-preserving surgery has been introduced to reduce the complications of conventional parotidectomy that requires removal of total superficial or entire parotid gland along with the tumour. Several cosmetic incisions have also been developed along with conservative parotid surgery involving partial dissection of the facial nerve and gland. The incision length in the cosmetic approaches is gradually shortened from facelift to periauricular incision, and endoscopic parotidectomy techniques emerged. A more functional approach via postauricular sulcus incision was also introduced to remove benign parotid tumours with high cosmetic satisfaction and oncological safety. Therefore, this article presents the surgical procedures, potential indications, pros and cons of the postauricular sulcus approach.

Tracing in vivo the dorsal loop of the optic radiation: convergent perspectives from tractography and electrophysiology compared to a neuroanatomical ground truth

The temporo-parietal junction (TPJ) is a cortical area contributing to a multiplicity of visual, language-related, and cognitive functions. In line with this functional richness, also the organization of the underlying white matter is highly complex and includes several bundles. The few studies tackling the outcome and neurological burdens of surgical operations addressing TPJ document the presence of language disturbances and visual field damages, with the latter hardly recovered in time. This observation advocates for identifying and functionally monitoring the optic radiation (OR) bundles that cross the white matter below the TPJ. In the present study, we adopted a multimodal approach to address the anatomo-functional correlates of the OR's dorsal loop. In particular, we combined cadavers' dissection with tractographic and electrophysiological data collected in drug-resistant epileptic patients explored by stereoelectroencephalography (SEEG). Cadaver dissection allowed us to appreciate the course and topography of the dorsal loop. More surprisingly, both tractographic and electrophysiological observations converged on a unitary picture highly coherent with the data obtained by neuroanatomical observation. The combination of diverse and multimodal observations allows overcoming the limitations intrinsic to single methodologies, defining a unitary picture which makes it possible to investigate the dorsal loop both presurgically and at the individual patient level, ultimately contributing to limit the postsurgical damages. Notwithstanding, such a combined approach could serve as a model of investigation for future neuroanatomical inquiries tackling white matter fibers anatomy and function through SEEG-derived neurophysiological data.

Endoscopic submucosal dissection: the first reported experience from a New Zealand centre

AIM

Endoscopic submucosal dissection (ESD) is internationally accepted as a minimally invasive procedure to treat early gastrointestinal cancers endoscopically. Uptake of this procedure in the West is limited. No published data are available in New Zealand. We aimed to evaluate outcomes of this procedure at North Shore Hospital, Auckland.

METHODS

Following an overseas fellowship training period, we prospectively collected clinical outcomes, complications and defined quality indicators for patients undergoing ESD referred following a multidisciplinary meeting.

RESULTS

Between January 2020 until July 2021, 29 ESD procedures were performed in 27 patients, including 14 gastric, five oesophageal and 10 colorectal cases. The mean age was 72 (standard deviation (SD) 10.6). The majority of cases (62%) were done under general anaesthesia. The median lesion size resected was 30mm (interquartile range (IQR) 20-58mm). The pre-endoscopic diagnosis was accurate as confirmed on final histology in 93% of cases. Thirty-four percent of lesions were T1 adenocarcinoma and completely resected. The median total duration of the procedure was 90 minutes (IQR 55-180). 86% of lesions were resected en-bloc. R0 resection was achieved in 72% of cases. All cases with R0 resection were curative except one. Muscular defects without perforation were seen and clipped at the time of endoscopy in 34% of cases. Two perforations were identified and sealed at the time of endoscopy. There were no cases of delayed bleeding, perforation or mortality.

CONCLUSION

These data demonstrate clinical success, efficacy and safety of ESD at our centre. A larger study, comparison with other centres and longer clinical follow-up is required to confirm findings and further improve outcomes.

Prognosis and risk factors of electrocoagulation syndrome after endoscopic submucosal dissection in the colon and rectum. Large cohort study

BACKGROUND

There are few studies on electrocoagulation syndrome after colorectal endoscopic submucosal dissection (ESD). This study aimed to investigate the various risk factors associated with thermal injury and to determine the prognosis of post-colorectal ESD electrocoagulation syndrome (PECS).

METHODS

We conducted a retrospective analysis of the medical records of 395 colorectal neoplasms of 508 patients who were treated with colorectal ESD between January 2013 and December 2019. The incidence, risk factors, and clinical outcomes of colorectal PECS were evaluated and analyzed.

RESULTS

Colorectal PECS occurred in 25 patients (6.3%). The PECS group had a larger lesion size (≥ 40 mm), lesions with fibrosis, longer procedure time, older age, and a larger amount of submucosal injection per square meter than the non-PECS group. In multivariate analysis, lesion with size ≥ 40 mm (odds ratio [OR] 16.941, 95% confidence interval [CI] 3.869-74.178), lesions with fibrosis (OR 7.127, 95% CI 2.541-19.984), old age (OR 1.068, 95% CI 1.010-1.130), and amount of submucosal injection per square meter (OR 1.067, 95% CI 1.015-1.121) were independent risk factors. The PECS group had more fasting days (3.08 vs 1.56 days, P < 0.001), longer hospital stays (7.04 vs 4.09 days, P < 0.001), and higher medical costs (2367 vs 2046, US$, P = 0.004) than the non-PECS group.

CONCLUSION

Lesions with size ≥ 40 mm, lesions with fibrosis, old age, and amount of submucosal injection per square meter were independent risk factors. Therefore, caution should be exercised when performing colorectal ESD in patients with these risk factors.

Comparison of the efficacy of endoscopic submucosal dissection and transanal endoscopic microsurgery in the treatment of rectal neuroendocrine tumors ≤ 2 cm

INTRODUCTION

Currently, complete tumor resection is considered the most effective treatment for rectal neuroendocrine tumors (NETs). Endoscopic submucosal dissection (ESD) and transanal endoscopic microsurgery (TEM) are recommended for rectalNETs ≤2 cm, but it is not clear which method is better. Thus, we evaluated the efficacy of ESD and TEM in the treatment of rectal neuroendocrine tumors (NETs) ≤ 2 cm.

METHODS

We conducted a single-centre retrospective cohort study between 2010 and 2021 of rectal NETs ≤ 2 cm in 114 patients with long-term follow-up data who were divided into ESD (n=55) and TEM groups (n=59). Our study assessed differences between groups in the complete resection rate of lesions, recurrence rate, surgical complications, procedure time, and length of hospital stay.

RESULTS

The co-primary outcomes were the complete resection rate of lesions and the recurrence rate. Compared to that in the ESD group, the complete resection rate was significantly higher in the TEM group (91.5% vs. 70.9%, p=0.005). The median follow-up time was 22 months in our study, and the follow-up outcomes suggested that the rates of recurrence were 1.8% (1/55) and 6.8% (4/59) in the ESD and TEM groups, respectively, with no significant difference between the two groups. The secondary outcomes of the evaluation were surgical complications, procedural time, and length of hospital stay. The rate of complications (gastrointestinal bleeding and perforation) was low in both the ESD (7.3%, 4/55) and TEM (5.1%, 3/59) groups. No difference in hospitalization duration was observed between the two groups in our study. However, the procedure time was significantly shorter in the ESD group than in the TEM group (27.5 min vs. 56 min, p<0.001).

CONCLUSIONS

Although the rate of complete resection in the TEM group was higher than that in the ESD group, there was no difference in recurrence rates between the two modalities during long-term follow-up. Depending on the qualities of the available hospital resources in the area, one of the two approaches can be adopted.

[One thousand endoscopic submucosal dissections. Experience of the national center]

BACKGROUND

Endoscopic submucosal dissection (ESD) is a perspective method of organ-sparing treatment of benign colon tumors.

MATERIAL AND METHODS

The study included 1.000 patients with colon neoplasms who underwent ESD between October 2016 and October 2021. All surgeries were performed under intravenous sedation.

RESULTS

Mean dimension of tumors was 3.4 cm, median of surgery time - 51 (31; 101) minutes. Conversion of endoscopic approach occurred in 7.6% of cases. The main cause of conversion was unsatisfactory lifting in submucosal injection process. Incidence of en bloc and R0 resections was 84.1% and 68.3%, respectively. Postoperative morbidity was 2.9% that correlates with the world literature data.

CONCLUSION

Endoscopic submucosal dissection is an effective and safe method for benign colon neoplasms. Considering high incidence of en bloc resection and low rate of local recurrence in benign neoplasms, further research of efficacy and safety of ESD in early colon cancer is needed.

Mechanistic dissection of dominant AIRE mutations in mouse models reveals AIRE autoregulation

The autoimmune regulator (AIRE) is essential for the establishment of central tolerance and prevention of autoimmunity. Interestingly, different AIRE mutations cause autoimmunity in either recessive or dominant-negative manners. Using engineered mouse models, we establish that some monoallelic mutants, including C311Y and C446G, cause breakdown of central tolerance. By using RNAseq, ATACseq, ChIPseq, and protein analyses, we dissect the underlying mechanisms for their dominancy. Specifically, we show that recessive mutations result in a lack of AIRE protein expression, while the dominant mutations in both PHD domains augment the expression of dysfunctional AIRE with altered capacity to bind chromatin and induce gene expression. Finally, we demonstrate that enhanced AIRE expression is partially due to increased chromatin accessibility of the AIRE proximal enhancer, which serves as a docking site for AIRE binding. Therefore, our data not only elucidate why some AIRE mutations are recessive while others dominant, but also identify an autoregulatory mechanism by which AIRE negatively modulates its own expression.

Lessons from Cadaver Dissection during the COVID-19 Pandemic

The rapid increase of the coronavirus disease 2019 pandemic from mid-February 2020 has led the anatomy department of the Korea University College of Medicine to cease the dissection laboratory. However, the hands-on anatomy laboratory experience is paramount to maximizing learning outcomes. In this paper, we share the experiences and lessons learned through the face-to-face cadaveric dissection experience during this disruptive situation. To minimize infection risks, the following strategies were applied: first, students' on-campus attendance was reduced; second, body temperatures and symptoms were checked before entering the laboratory, and personal protective equipment was provided to all participants; and third, a negative pressure air circulation system was used in the dissection room. We suggest that conducting face-to-face cadaveric anatomy dissection is feasible when the daily count of newly infected cases stabilizes, and there is ample provision of safety measures to facilitate hands-on education.

Safety and efficacy of cold snare polypectomy for small colorectal polyps: A prospective randomized control trial and one-year follow-up study

TRIAL DESIGN

Elimination of small colorectal polyps with cold snare polypectomy (CSP) is reported to be as safe as hot snare polypectomy (HSP). The effectiveness of CSP has not been clearly defined, and the incidence of long-term recurrence has not been determined. We conducted a randomized control study and one-year follow-up study to assess their safety and efficacy.

METHODS

Patients with small colorectal polyps were randomized to receive CSP or HSP. Polypectomy was performed to determine the pathological curability, and patients completed a questionnaire about the tolerability of the procedure. Follow-up colonoscopy was performed to determine the local recurrence of adenoma. The major outcome was the non-inferiority of CSP to HSP in the rate of delayed bleeding and minor outcomes, including the incidence of immediate bleeding and perforation, procedural time, and the resection rate.

RESULTS

A total of 119 participants were recruited in this randomized study and underwent polypectomy. Among the 458 polyps, 332 eligible polyps were analyzed. The rate of adverse events was 0.6% (1/175) for CSP and 0% (0/157) for HSP, which showed the non-inferiority of CSP. While the complete resection rate of CSP was very high (100%), the R0 rate was not satisfactory (horizontal margin, 65.5%; vertical margin, 89.1%). Two local recurrences (2.5%) were observed in the follow-up of 80 adenomas treated with CSP. No recurrence was found in 79 lesions in the HSP group, which was not significant (P = .06).

CONCLUSIONS

Colorectal polyps were safely resected using CSP, similar to HSP. Most would agree to say that CSP is considered safer than HSP. The main question is then related to efficacy. Our results of the present study demonstrate that recurrence after CSP should be carefully managed for curative treatment.

Dissection of the potential pharmacological function of neohesperidin dihydrochalcone - a food additive - by in vivo substances profiling and network pharmacology

Food additives are widely used in our daily life, and the side-effects caused by them have gained extensive attention around the world. Notably, constituent-oriented metabolites, in some sense, always contribute to pharmacological changes, inducing toxicity, therapeutic effects, etc. Characterization of the metabolites and their potential functions is of great importance to the practical applications. In this work, an integrated strategy by combining metabolite profiling and network pharmacology was applied to characterize the metabolic features and reveal pharmacological changes of neohesperidin dihydrochalcone (NHDC) in vivo to demonstrate its pharmacological mechanism and potential functions. As a result, a total of 19 metabolites (3 in plasma, 19 in urine, 8 in feces, 3 in heart, 5 in liver, 0 in spleen, 1 in lung, 2 in kidneys and 2 in brain) were screened and 18 of them were characterized for the first time. Phase I metabolic reactions of hydrolysis and phase II reactions of glucuronidation, sulfation, glutamylation, N-butyryl glycylation and lactylation were the main metabolic reactions of NHDC in vivo. Moreover, the results analyzed by network pharmacology revealed that, in addition to common pathways (steroid hormone biosynthesis) of NHDC, metabolites' targets were involved in pathways in cancer, ovarian steroidogenesis, proteoglycans in cancer, PI3K-Akt signaling pathway and progesterone-mediated oocyte maturation, indicating that these functional changes might result in potential novel functions or other side-effects, such as a disorder of steroid hormones. Our work provided the metabolic features and functional modifications of NHDC in vivo for the first time, and meaningful information for further pharmacological validations or potential functions is supplied.