General anatomy of the esophagus

New and Evolving Treatments for Neurologic Dysphagia

Despite swallowing being a frequently performed daily function, it is highly complex. For a safe swallow to occur, muscles within the head, neck, and thorax need to contract in a concerted pattern, controlled by several swallowing centers at multiple levels of the central nervous system, including the midbrain, cerebral cortex, and cerebellum in addition to five cranial nerves. Dysphagia, or difficulty swallowing, is caused by a long list of pathologic processes and diseases, which can interfere with various stages along the swallowing sensorimotor pathway. When present, dysphagia leads to increased mortality, morbidity, hospital length of stay, and reduced quality of life. Current dysphagia management approaches, such as altering the texture and consistency of foods and fluids and teaching patients rehabilitative exercises, have been broadly unchanged for many years and, in the case of texture modification, are of uncertain effectiveness. However, evidence is emerging in support of new medication-based and neuromodulatory treatment approaches. Regarding medication-based therapies, most research has focused on capsaicinoids, which studies have shown are able to improve swallowing in patients with post-stroke dysphagia. Separately, albeit convergently, in the field of neuromodulation, there is a growing and positive evidential base behind three non-invasive brain stimulation techniques: repetitive transcranial magnetic stimulation (rTMS), transcranial direct current stimulation (TDCS), and pharyngeal electrical stimulation (PES). Should some or all of these emerging therapies fulfill their promise, dysphagia-related patient outcomes may be improved. This paper describes the current state of our understanding regarding new medication and neuromodulation-based neurogenic oropharyngeal dysphagia treatments.

Morphology and Mechanics of the Fin Whale Esophagus: The Key to Fast Processing of Large Food Volumes by Rorquals

Lunge feeding rorqual whales feed by engulfing a volume of prey laden water that can be as large as their own body. Multiple feeding lunges occur during a single foraging dive and the time between each lunge can be as short as 30 s (Goldbogen et al. 2013). During this short inter-lunge time, water is filtered out through baleen to concentrate prey in the oral cavity, and then the prey is swallowed prior to initiating the next lunge. Prey density in the ocean varies greatly, and despite the potential of swallowing a massive volume of concentrated prey as a slurry, the esophagus of rorqual whales has been anecdotally described as unexpectedly narrow with a limited capacity to expand. How rorquals swallow large quantities of food down a narrow esophagus during a limited inter-lunge time remains unknown. Here, we show that the small diameter muscular esophagus in the fin whale is optimized to transport a slurry of food to the stomach. A thick wall of striated muscle occurs at the pharyngeal end of the esophagus which, together with the muscular wall of the pharynx, may generate a pressure head for transporting the food down the esophagus to the stomach as a continuous stream rather than separating the food into individual boluses swallowed separately. This simple model is consistent with estimates of prey density and stomach capacity. Rorquals may be the only animals that capture a volume of food too large to swallow as a single intact bolus without oral processing, so the adaptations of the esophagus are imperative for transporting these large volumes of concentrated food to the stomach during a time-limited dive involving multiple lunges.

Recent research advances on oral colon-specific delivery system of nature bioactive components: A review

Oral colon-specific delivery system (OCDS) is a targeted approach that aims to directly deliver bioactive compounds directly to the colon following oral administration, thereby enhancing the colonic release of bioactive substances and minimizing adverse reactions. The effectiveness of bioactive substances in the colon hinges on the degree of release, which are affected by various factors including pH, mucosal barrier, delivery time and so on. Therefore, this review provides a comprehensive overview of the key factors affecting oral colon-specific release of bioactive components firstly. Considering the oral safety, this review then mainly focuses on the types of carriers with edible OCDS and preparation strategies for OCDS. Finally, several preparation strategies for loading typical natural bioactive ingredients into oral safe OCDS are reviewed, along with future development prospects.

Comparative Evaluations on Real-Time Monitoring of Temperature Sensors during Endoscopic Laser Application

Temperature sensors, such as Fiber Bragg Grating (FBG) and thermocouple (TC), have been widely used for monitoring the interstitial tissue temperature during laser irradiation. The aim of the current study was to compare the performance of both FBG and TC in real-time temperature monitoring during endoscopic and circumferential laser treatment on tubular tissue structure. A 600-µm core-diameter diffusing applicator was employed to deliver 980-nm laser light (30 W for 90 s) circumferentially for quantitative evaluation. The tip of the TC was covered with a white tube (W-TC) in order to prevent direct light absorption and to minimize temperature overestimation. The temperature measurements in air demonstrated that the measurement difference in the temperature elevations was around 3.5 °C between FBG and W-TC. Ex vivo porcine liver tests confirmed that the measurement difference became lower (less than 1 °C). Ex vivo porcine esophageal tissue using a balloon-integrated catheter exhibited that both FBG and W-TC consistently showed a comparable trend of temperature measurements during laser irradiation (~2 °C). The current study demonstrated that the white tube-covered TC could be a feasible sensor to monitor interstitial tissue temperature with minimal overestimation during endoscopic laser irradiation. Further in vivo studies on gastroesophageal reflux disease will investigate the performance of the W-TC to monitor the temperature of the esophageal mucosa surface in real-time mode to warrant the safety of endoscopic laser treatment.

MRI-MECH: mechanics-informed MRI to estimate esophageal health

Dynamic magnetic resonance imaging (MRI) is a popular medical imaging technique that generates image sequences of the flow of a contrast material inside tissues and organs. However, its application to imaging bolus movement through the esophagus has only been demonstrated in few feasibility studies and is relatively unexplored. In this work, we present a computational framework called mechanics-informed MRI (MRI-MECH) that enhances that capability, thereby increasing the applicability of dynamic MRI for diagnosing esophageal disorders. Pineapple juice was used as the swallowed contrast material for the dynamic MRI, and the MRI image sequence was used as input to the MRI-MECH. The MRI-MECH modeled the esophagus as a flexible one-dimensional tube, and the elastic tube walls followed a linear tube law. Flow through the esophagus was governed by one-dimensional mass and momentum conservation equations. These equations were solved using a physics-informed neural network. The physics-informed neural network minimized the difference between the measurements from the MRI and model predictions and ensured that the physics of the fluid flow problem was always followed. MRI-MECH calculated the fluid velocity and pressure during esophageal transit and estimated the mechanical health of the esophagus by calculating wall stiffness and active relaxation. Additionally, MRI-MECH predicted missing information about the lower esophageal sphincter during the emptying process, demonstrating its applicability to scenarios with missing data or poor image resolution. In addition to potentially improving clinical decisions based on quantitative estimates of the mechanical health of the esophagus, MRI-MECH can also be adapted for application to other medical imaging modalities to enhance their functionality.

Development of Bio-artificial Esophageal Tissue Engineering Utilization for Circumferential Lesion Transplantation: A Narrative Review

The esophagus is the gastrointestinal tract's primary organ that transfers bolus into the stomach with peristaltic motion. Therefore, its lesions cause a significant disturbance in the nutrition and digestive system. Esophageal disease treatment sometimes requires surgical procedures that involve removal and circumferential full-thickness replacement. Unlike other organs, the esophagus has a limited regeneration ability and cannot be transplanted from donors. There are various methods of restoring the esophageal continuity; however, they are associated with certain flaws that lead to a non-functional recovery. As an exponentially growing science, tissue engineering has become a leading technique for the development of tissue replacement to repair damaged esophageal segments. Scaffold plays a significant role in the process of tissue engineering, as it acts as a template for the regeneration of growing tissue. A variety of scaffolds have been studied to replace the esophagus. Due to the many tissue quality challenges, the results are still inadequate and need to be improved. The success of esophageal tissue regeneration will finally depend on the scaffold's capability to mimic natural tissue properties and provide a qualified environment for regeneration. Thereby, scaffold fabrication techniques are fundamental. This article reviews the recent developments in esophageal tissue engineering for the treatment of circumferential lesions based on scaffold biomaterial engineering approaches.

Penetrating esophageal injury: A diagnostic challenge in resource-limited settings; a case report

Introduction

Penetrating injuries to the upper aerodigestive tract are potentially life-threatening, with significant morbidity and mortality. Although rare, the cervical esophagus is the most vulnerable part of the esophagus to penetrating injuries. Given the unique and condensed anatomy of the neck, penetrating injuries to the second zone of the neck pose a demanding challenge. Contention exists in diagnosing and managing penetrating esophageal injuries.

Case presentation

Herein is a case of a young male with a penetrating neck injury from the left lateral aspect with subsequent esophageal injury. An early primary repair with muscle buttress resulted in admirable results.

Discussion

Accurate diagnosis and timely management are critical in deflating morbidity and mortality. Flexible esophagoscopy and Computed tomography with water-soluble contrast are the ideal modalities for diagnosing penetrating neck injuries, as clinical evaluation alone can readily overlook cervical esophagus injury. The esophageal repair depends on the patient's clinical condition, the extent of damage, anatomical location, and duration of the injury. Management varies from a conservative approach to radical esophagectomies. Surgery remains a cornerstone in managing penetrating esophageal injuries. Primary repair with an external drain is advocated within 24 h of injury.

Conclusion

A high index of suspicion and timely diagnosis are critical in successfully managing penetrating esophageal injuries. Neck injuries demand a comprehensive evaluation for any aerodigestive or vascular leaks. Early primary repair with a muscle buttress improves the chance of an effective repair.

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Penetrating esophageal injuries are rare, with high morbidity and mortality.

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Appropriate investigations are critical in the evaluation of neck injuries.

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Early diagnosis and timely surgical management are crucial in outcomes of management.

Efficient Initial Eradication of Large Esophageal Varices by Balloon-compression Endoscopic Injection Sclerotherapy

BACKGROUND

The management of large esophageal varices (EVs) remains challenging because of the difficulty of endoscopic variceal ligation and fatal post-endoscopic variceal ligation bleeding ulcers. The current study evaluated the efficacy and safety of balloon-compression endoscopic injection sclerotherapy (bc-EIS) in the treatment of large EVs.

MATERIALS AND METHODS

This retrospective study included 105 patients with cirrhosis exhibiting large EVs (64 in the bc-EIS group and 41 in the EIS group). Primary outcomes included the initial rate of variceal eradication and intraoperative bleeding signs. Secondary outcomes included incidences of rebleeding, mortality, complications, and optimal time of balloon-compression (bc).

RESULTS

The initial rate of variceal eradication in the bc-EIS group was significantly higher than that in the EIS group (46.9 vs. 24.4%; P=0.021). The incidence of intraoperative bleeding, which was represented as oozing and spurting, in the bc-EIS group was markedly lower than that in the EIS group (43.8 vs. 61.0% and 9.4 vs. 39.0%, respectively; P=0.043). Patients in the bc-EIS group showed a significantly lower incidence of rebleeding (0.0 vs. 17.1%; P=0.001). However, no significant difference in mortality rate was observed between different groups. Chest pain or discomfort tended to be more common in the EIS group than in the bc-EIS group (58.5 vs. 17.2%; P=0.001). The cut-off value of 11.5-minutes appeared to have a maximum combined sensitivity and specificity of 80.0% and 58.8%, respectively. The area under the curve was 0.708 (95% confidence interval =0.576-0.839; P=0.004).

CONCLUSION

bc-EIS could achieve a higher variceal eradication rate and milder intraoperative bleeding signs in large EVs. Furthermore, 11.5-minutes appeared to be the optimal compression time in bc-EIS.

A Universal Strategy for Growing a Tenacious Hydrogel Coating from a Sticky Initiation Layer

Controllably coating the surfaces of substrates/medical devices with hydrogels exhibits great application potential, but lacks universal techniques. Herein, a new method, namely ultraviolet-triggered surface catalytically initiated radical polymerization (UV-SCIRP) from a sticky initiation layer (SIL) (SIL@UV-SCIRP), is proposed for growing hydrogel coatings. The method involves three key steps: 1) depositing a sticky polydopamine/Fe³⁺ coating on the surface of the substrates-SIL, 2) reducing Fe³⁺ ions to Fe²⁺ ions as active catalysts by UV illumination with the assistance of citric acid, and 3) conducting SCIRP in a monomer solution at room temperature for growing hydrogel coatings. In this manner, practically any substrate's surface (natural or artificial materials) can be modified by hydrogel coatings with controllable thickness and diverse compositions. The hydrogel coatings exhibit good interface bonding with the substrates and enable easy changes in their wettability and lubrication performances. Importantly, this novel method facilitates the smooth growth of uniform hydrogel lubrication coatings on the surface of a range of medical devices with complex geometries. Finally, as a proof-of-concept, the slippery balls coated with hydrogel exhibited smooth movement within the catheter and esophagus. Hence, this method can prove to be a pioneering universal modification tool, especially in surface/interface science and engineering.

The upper esophageal sphincter in the high-resolution manometry era

BACKGROUND

The evaluation of the upper esophageal sphincter (UES) has been neglected during routine manometric tests for decades, mostly due to the limitations of the conventional manometry which were eventually overcome by high-resolution manometry (HRM).

METHODS

This study reviewed the current knowledge of the manometric evaluation of the UES in health and disease in the HRM era.

RESULTS

We found that HRM allowed more precise measurements, in addition to the parameters as compared to conventional manometry, but most of them still need confirmation of the clinical significance. The parameters used to evaluate the UES were extension, basal pressure, residual pressure, relaxation duration, relaxation time to nadir, recovery time, intrabolus pressure, and deglutitive sphincter resistance. UES may be affected by different diseases: achalasia (UES is hypertonic with impaired relaxation), gastroesophageal reflux disease (UES is short and hypotonic), globus (UES ranges from normal to impaired relaxation to hypertonic), neurologic diseases (stroke and Parkinson - UES is hypotonic in early-stage to impaired relaxation in end-stage disease), and Zenker's diverticulum (UES has impaired relaxation).

CONCLUSION

This review shows that UES dysfunction is part of several disease processes and that the study of the UES is possible and valuable with the aid of HRM.

A Scarless Healing Tale: Comparing Homeostasis and Wound Healing of Oral Mucosa With Skin and Oesophagus

Epithelial tissues are the most rapidly dividing tissues in the body, holding a natural ability for renewal and regeneration. This ability is crucial for survival as epithelia are essential to provide the ultimate barrier against the external environment, protecting the underlying tissues. Tissue stem and progenitor cells are responsible for self-renewal and repair during homeostasis and following injury. Upon wounding, epithelial tissues undergo different phases of haemostasis, inflammation, proliferation and remodelling, often resulting in fibrosis and scarring. In this review, we explore the phenotypic differences between the skin, the oesophagus and the oral mucosa. We discuss the plasticity of these epithelial stem cells and contribution of different fibroblast subpopulations for tissue regeneration and wound healing. While these epithelial tissues share global mechanisms of stem cell behaviour for tissue renewal and regeneration, the oral mucosa is known for its outstanding healing potential with minimal scarring. We aim to provide an updated review of recent studies that combined cell therapy with bioengineering exporting the unique scarless properties of the oral mucosa to improve skin and oesophageal wound healing and to reduce fibrotic tissue formation. These advances open new avenues toward the ultimate goal of achieving scarless wound healing.

Improved submucosal tunneling endoscopic resection with slant tunnel for submucosal tumors in proximal esophagus

BACKGROUND

The improved submucosal tunneling endoscopic resection (STER) with slant tunnel was created by our group innovatively for submucosal tumors (SMTs) in the proximal esophagus. This study aimed to provide the preliminary results of the improved STER from our center.

METHODS

The key step of the improved STER is establishing a slant tunnel instead of a vertical tunnel. After a longitudinal incision was made proximally in the inclined top to the tumor, a submucosal tunnel was established from the incision to the SMT slantingly. 28 patients undergoing STER with slant tunnel were enrolled in the retrospective study. Clinical results including en bloc resection, curative resection and complication were collected.

RESULTS

All the submucous tumors located at proximal esophagus originated from muscularis propria were successfully resected by the innovative STER. Tumor size ranged from 18-43 mm, with 96.4% (27/28) en bloc resection rate and 92.9% (26/28) curative rate. Three patients suffered complication, 1 patient with mild pleural effusion and another 2 patients with fever for one day. All of the complications were cured by conservative treatment.

CONCLUSIONS

STER with slant tunnel seems to provide an optional treatment for tumors in proximal esophagus.

Understanding the cellular origin and progression of esophageal cancer using esophageal organoids

Three-dimensional (3D) organoids are a novel tool to model epithelial cell biology and human diseases of the esophagus. 3D organoid culture systems have been utilized to investigate the pathobiology of esophageal cancer, including both squamous cell carcinoma and adenocarcinoma. Additional organoid-based approaches for study of esophageal development and benign esophageal diseases have provided key insights into esophageal keratinocyte differentiation and mucosal regeneration. These investigations have implications for the identification of esophageal cancer stem cells, as well as the potential to halt malignant progression through induction of differentiation pathways. Patient-derived organoids (PDOs) from human tissue samples allow for unique and faithful in vitro modeling of esophageal cancers, and provide an exciting platform for investigation into personalized medicine and targeted treatment approaches, as well as new models for understanding therapy resistance and recurrent disease. Future directions include high-throughput genomic screening using PDOs, and study of tumor-microenvironmental interactions through co-culture with immune and stromal cells and novel extracellular matrix complexes.

Role of Imaging in Esophageal Cancer Management in 2020: Update for Radiologists

OBJECTIVE. The purpose of this article is to discuss the role of imaging in the management of esophageal cancer. CONCLUSION. A multimodality-based approach to imaging is essential in clinical practice to achieve the best possible outcome for patients with esophageal cancer. Radiologists must be aware of the strengths and limitations of different imaging modalities in various clinical settings. The role of a radiologist is to combine information from anatomic and functional imaging, assess metastatic disease and changes in the primary tumor during treatment, and identify anatomic complications after treatment.

Sonographic demonstration of fetal esophagus using three-dimensional ultrasound imaging

OBJECTIVE

To evaluate the feasibility of antenatal direct visualization of normal and abnormal fetal esophagus using three-dimensional ultrasound (3D-US) with Crystal Vue rendering technology.

METHODS

Between February and April 2018, 3D-US volumes were collected from a non-consecutive series of singleton pregnancies, referred for clinically indicated detailed prenatal ultrasound at 19-28 weeks' gestation to one of two fetal medicine units in Italy. 3D volumes were acquired from a midsagittal section of the fetal thorax and upper abdomen with the fetus lying in supine position. Postprocessing with multiplanar mode was applied to orientate the volume and identify the esophagus. The region of interest was angled by approximately 30° to the spine and its thickness was adjusted in order to optimize visualization of the intrathoracic and intra-abdominal course of the esophagus. Crystal Vue software was used for image rendering of the fetal trunk in the coronal plane. Postnatal follow-up was available in all cases.

RESULTS

During the study period, 91 pregnancies met the inclusion criteria and were recruited. The study cohort included two pregnancies with suspicion of esophageal atresia due to suboptimal visualization of the stomach. Of the 89 cases with normal stomach on two-dimensional (2D) imaging, 3D-US with Crystal Vue rendering technology allowed direct evaluation of the whole course of the esophagus in 74 (83.1%). In the two cases with small or absent stomach bubble on 2D imaging, esophageal atresia was demonstrated antenatally on 3D Crystal Vue imaging and was confirmed postnatally. The mean time required for offline postprocessing and visualization of the esophageal anatomy was 4 min.

CONCLUSIONS

Using 3D-US with Crystal Vue rendering, it is possible to visualize antenatally the normal fetal esophagus and demonstrate presence of esophageal atresia. This should facilitate prenatal counseling and management of cases with suspected esophageal atresia. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Esophageal dysmotility: An intrinsic feature of megacystis, microcolon, hypoperistalsis syndrome (MMIHS)

OBJECTIVES

Megacystis-microcolon-hypoperistalsis syndrome (MMIHS) also called Berdon's Syndrome, is a smooth muscle myopathy that results in an enlarged bladder, microcolon, and small bowel hypoperistalsis. In our series of six patients with this disorder, all had disordered swallowing. Therefore, we prospectively characterized esophageal structure and function in all.

METHODS

Diagnoses had been established by contrast radiography, small bowel manometry, and urodynamic studies. To investigate the esophagus, we endoscoped and biopsied the esophagus of each patient on multiple occasions. All patients also underwent water soluble contrast esophagography and esophageal manometry.

RESULTS

Upon careful questioning, all patients had swallowing dysfunction, and the majority of their enteral intake was via gastrostomy or gastrojejunostomy. All took some oral alimentation, but eating was slow and none could aliment themselves completely by the oral route, receiving 50% or less of their calories by mouth. Four had megaesophagus whereas the esophagus of the two youngest was of normal caliber. All had eosinophilic esophagitis and/or esophageal Candidiasis from time to time, but successful treatment of these findings failed to improve their symptoms. Manometry revealed normal lower esophageal sphincter (LES) resting tone and normal LES relaxation, but for all, peristalsis was absent in the esophageal body.

CONCLUSIONS

This series expands the spectrum of findings in MMIHS, to include a primary motility disorder of the esophageal body. As patients age, the esophageal caliber appears to increase. Successful treatment of neither esophageal eosinophilia nor Candidiasis is effective in ameliorating the motility disorder. If our findings are confirmed in more patients with MMIHS, this disorder should be renamed, megacystis-microcolon-intestinal-and esophageal hypoperistalsis syndrome.

TYPE OF STUDY

Prognosis study, Level IV (case series).

Esophagram findings in cervical esophageal stenosis: A case-controlled quantitative analysis

OBJECTIVE

Cervical esophageal stenosis is often diagnosed with a qualitative evaluation of a barium esophagram. Although the esophagram is frequently the initial screening exam for dysphagia, a clear objective standard for stenosis has not been defined. In this study, we measured esophagram diameters in order to establish a quantitative standard for defining cervical esophageal stenosis that requires surgical intervention.

STUDY DESIGN

Single institution case-control study.

METHODS

Patients with clinically significant cervical esophageal stenosis defined by moderate symptoms of dysphagia (Functional Outcome Swallowing Scale > 2 and Functional Oral Intake Scale < 6) persisting for 6 months and responding to dilation treatment were matched with age, sex, and height controls. Both qualitative and quantitative barium esophagram measurements for the upper, mid-, and lower vertebral bodies of C5 through T1 were analyzed in lateral, oblique, and anterior-posterior views.

RESULTS

Stenotic patients versus nonstenotic controls showed no significant differences in age, sex, height, body mass index, or ethnicity. Stenosis was most commonly at the sixth cervical vertebra (C 6) lower border and C7 upper border. The mean intraesophageal minimum/maximum ratios of controls and stenotic groups in the lateral view were 0.63 ± 0.08 and 0.36 ± 0.12, respectively (P < 0.0001). Receiver operating characteristic analysis of the minimum/maximum ratios, with a <0.50 ratio delineating stenosis, demonstrated that lateral view measurements had the best diagnostic ability. The sensitivity of the radiologists' qualitative interpretation was 56%. With application of lateral intraesophageal minimum/maximum ratios, we observed improved sensitivity to 94% of the esophagram, detecting clinically significant stenosis.

CONCLUSION

Applying quantitative determinants in esophagram analysis may improve the sensitivity of detecting cervical esophageal stenosis in dysphagic patients who may benefit from surgical therapy.

LEVEL OF EVIDENCE

IIIb. Laryngoscope, 128:2022-2028, 2018.

Imaging of the oesophagus: beyond cancer

Abstract

Non-malignant oesophageal diseases are critical to recognize, but can be easily overlooked or misdiagnosed radiologically. In this paper, we cover the salient clinical features and imaging findings of non-malignant pathology of the oesophagus. We organize the many non-malignant diseases of the oesophagus into two major categories: luminal disorders and wall disorders. Luminal disorders include dilatation/narrowing (e.g. achalasia, scleroderma, and stricture) and foreign body impaction. Wall disorders include wall thickening (e.g. oesophagitis, benign neoplasms, oesophageal varices, and intramural hematoma), wall thinning/outpouching (e.g. epiphrenic diverticulum, Zenker diverticulum, and Killian-Jamieson diverticulum), wall rupture (e.g. iatrogenic perforation, Boerhaave Syndrome, and Mallory-Weiss Syndrome), and fistula formation (e.g. pericardioesophageal fistula, tracheoesophageal fistula, and aortoesophageal fistula). It is the role of the radiologist to recognize the classic imaging patterns of these non-malignant oesophageal diseases to facilitate the delivery of appropriate and prompt medical treatment.

Teaching Points

• Nonmalignant oesophageal disease can be categorised by the imaging appearance of wall and lumen.

• Scleroderma and achalasia both cause lumen dilatation via different pathophysiologic pathways.

• Oesophageal wall thickening can be inflammatory, neoplastic, traumatic, or vascular in aetiology.

Esophageal cancer: anatomic particularities, staging, and imaging techniques

Cancer of the esophagus is a tumor with aggressive behavior that is usually diagnosed in advanced stages. The absence of serosa allows it to spread quickly to neighboring mediastinal structures, and an extensive lymphatic drainage network facilitates tumor spread even in early stages. The current TNM classification, harmonized with the classification for gastric cancer, provides new definitions for the anatomic classification, adds non-anatomic characteristics of the tumor, and includes tumors of the gastroesophageal junction. Combining endoscopic ultrasound, computed tomography, positron emission tomography, and magnetic resonance imaging provides greater accuracy in determining the initial clinical stage, and these imaging techniques play an essential role in the selection, planning, and evaluation of treatment. In this article, we review some particularities that explain the behavior of this tumor and we describe the current TNM staging system; furthermore, we discuss the different imaging tests available for its evaluation and include a diagnostic algorithm.

Innervation of the human cricopharyngeal muscle by the recurrent laryngeal nerve and external branch of the superior laryngeal nerve

PURPOSE

The major component of the upper esophageal sphincter is the cricopharyngeal muscle (CPM). We assessed the contribution of the laryngeal nerves to motor innervation of the CPM.

METHODS

We performed an intraoperative electromyographic study of 27 patients. The recurrent laryngeal nerve (RLN), vagus nerve, external branch of the superior laryngeal nerve (EBSLN), and pharyngeal plexus (PP) were stimulated. Responses were evaluated by visual observation of CPM contractions and electromyographic examination via insertion of needle electrodes into the CPM.

RESULTS

In total, 46 CPMs (24 right, 22 left) were evaluated. PP stimulation produced both positive visual contractions and electromyographic (EMG) responses in 42 CPMs (2080 ± 1583 μV). EBSLN stimulation produced visual contractions of 28 CPMs and positive EMG responses in 35 CPMs (686 ± 630 μV). Stimulation of 45 RLNs produced visible contractions of 37 CPMs and positive EMG activity in 41 CPMs (337 ± 280 μV). Stimulation of 42 vagal nerves resulted in visible contractions of 36 CPMs and positive EMG responses in 37 CPMs (292 ± 229 μV). Motor activity was noted in 32 CPMs by both RLN and EBSLN stimulation, 9 CPMs by RLN stimulation, and 3 CPMs by EBSLN stimulation; 2 CPMs exhibited no response.

CONCLUSIONS

This is the first study to show that the EBSLN contributes to motor innervation of the human CPM. The RLN, EBSLN, or both of the nerves innervate the 90, 75, and 70 % of the CPMs ipsilaterally, respectively.

A new concept of the anatomy of the thoracic oesophagus: the meso-oesophagus. Observational study during thoracoscopic esophagectomy

BACKGROUND

During thoracoscopic oesophageal surgery, we observed not previously described fascia-like structures. Description of similar structures in rectal cancer surgery was of paramount importance in improving the quality of resection. Therefore, we aimed to describe a new comprehensive concept of the surgical anatomy of the thoracic oesophagus with definition of the meso-oesophagus.

METHODS

We retrospectively evaluated 35 consecutive unedited videos of thoracoscopic oesophageal resections for cancer, to determine the surgical anatomy of the oesophageal fascia's vessels and lymphatic drainage. The resulting concept was validated in a prospective study, including 20 patients at three different centres. Additional confirmation was sought by a histologic study of a cadaver's thorax.

RESULTS

A thin layer of connective tissue around the infracarinal oesophagus, involving the lymph nodes at the level of the carina, was observed during thoracoscopic esophagectomy in 32 of the 35 patients included in the retrospective study and in 19 of the 20 patients included in the prospective study. A thick fascia-like structure from the upper thoracic aperture to the lower thoracic aperture was visualized in all patients. This fascia is encountered between the descending aorta and left aspect of the infracarinal oesophagus. Above the carina it expands on both sides of the oesophagus to lateral mediastinal structures. This fascia contains oesophageal vessels, lymph vessels and nodes and nerves. The histologic study confirmed these findings.

CONCLUSIONS

Here we described the concept of the "meso-oesophagus". Applying the description of the meso-oesophagus will create a better understanding of the oesophageal anatomy, leading to more adequate and reproducible surgery.

Review on novel concepts of columnar lined esophagus

BACKGROUND

Columnar lined esophagus (CLE) is a marker for gastroesophageal reflux and associates with an increased cancer risk among those with Barrett's esophagus. Recent studies fostered the development of integrated CLE concepts.

METHODS

Using PubMed, we conducted a review of studies on novel histopathological concepts of nondysplastic CLE.

RESULTS

Two histopathological concepts-the squamo-oxyntic gap (SOG) and the dilated distal esophagus (DDE), currently model our novel understanding of CLE. As a consequence of reflux, SOG interposes between the squamous lined esophagus and the oxyntic mucosa of the proximal stomach. Thus the SOG describes the histopathology of CLE within the tubular esophagus and the DDE, which is known to develop at the cost of a shortened lower esophageal sphincter and foster increased acid gastric reflux. Histopathological studies of the lower end of the esophagus indicate, that the DDE is reflux damaged, dilated, gastric type folds forming esophagus and cannot be differentiated from proximal stomach by endoscopy. While the endoscopically visible squamocolumnar junction (SCJ) defines the proximal limit of the SOG, the assessment of the distal limit requires the histopathology of measured multilevel biopsies. Within the SOG, CLE types distribute along a distinct zonation with intestinal metaplasia (IM; Barrett's esophagus) and/or cardiac mucosa (CM) at the SCJ and oxyntocardiac mucosa (OCM) within the distal portion of the SOG. The zonation follows the pH-gradient across the distal esophagus. Diagnosis of SOG and DDE includes endoscopy, histopathology of measured multi-level biopsies from the distal esophagus, function, and radiologic tests. CM and OCM do not require treatment and are surveilled in 5 year intervals, unless they associate with life quality impairing symptoms, which demand medical or surgical therapy. In the presence of an increased cancer risk profile, it is justified to consider radiofrequency ablation (RFA) of IM within clinical studies in order to prevent the progression to dysplasia and cancer. Dysplasia justifies RFA ± endoscopic resection.

CONCLUSIONS

SOG and DDE represent novel concepts fusing the morphological and functional aspects of CLE. Future studies should examine the impact of SOG and DDE for monitoring and management of gastroesophageal reflux disease (GERD).