Electrosurgical Knife Research Articles

Real-time oncological guidance using diffuse reflectance spectroscopy in electrosurgery: the effect of coagulation on tissue discrimination

In breast surgery, a lack of knowledge about what is below the tissue surface may lead to positive tumor margins and iatrogenic damage. Diffuse reflectance spectroscopy (DRS) is a spectroscopic technique that can distinguish between healthy and tumor tissue making it a suitable technology for intraoperative guidance. However, because tumor surgeries are often performed with an electrosurgical knife, the effect of a coagulated tissue layer on DRS measurements must be taken into account. It is evaluated whether real-time DRS measurements obtained with a photonic electrosurgical knife could provide useful information of tissue properties also when tissue is coagulated and cut. The size of the coagulated area is determined and the effect of its presence on DR spectra is studied using ex vivo porcine adipose and muscle tissue. A coagulated tissue layer with a depth of 0.1 to 0.4mm is observed after coagulating muscle with an electrosurgical knife. The results show that the effect of coagulating adipose tissue is negligible. Using the fat/water ratio's calculated from the measured spectra of the photonic electrosurgical knife, it was possible to determine the distance from the instrument tip to a tissue transition during cutting. In conclusion, the photonic electrosurgical knife can determine tissue properties of coagulated and cut tissue and has, therefore, the potential to provide real-time feedback about the presence of breast tumor margins during cutting, helping surgeons to establish negative margins and improve patient outcome.

Specimen fragmentation and outcomes of loop electrosurgical excision procedures (LEEP) and cold knife cone biopsies (CKC) for cervical dysplasia at a large, underserved public hospital

Specimen fragmentation and outcomes of loop electrosurgical excision procedures (LEEP) and cold knife cone biopsies (CKC) for cervical dysplasia at a large, underserved public hospital

A real time metabolomic profiling approach to detecting fish fraud using rapid evaporative ionisation mass spectrometry

IntroductionFish fraud detection is mainly carried out using a genomic profiling approach requiring long and complex sample preparations and assay running times. Rapid evaporative ionisation mass spectrometry (REIMS) can circumvent these issues without sacrificing a loss in the quality of results.ObjectivesTo demonstrate that REIMS can be used as a fast profiling technique capable of achieving accurate species identification without the need for any sample preparation. Additionally, we wanted to demonstrate that other aspects of fish fraud other than speciation are detectable using REIMS.Methods478 samples of five different white fish species were subjected to REIMS analysis using an electrosurgical knife. Each sample was cut 8–12 times with each one lasting 3–5 s and chemometric models were generated based on the mass range m/z 600–950 of each sample.ResultsThe identification of 99 validation samples provided a 98.99% correct classification in which species identification was obtained near-instantaneously (≈ 2 s) unlike any other form of food fraud analysis. Significant time comparisons between REIMS and polymerase chain reaction (PCR) were observed when analysing 6 mislabelled samples demonstrating how REIMS can be used as a complimentary technique to detect fish fraud. Additionally, we have demonstrated that the catch method of fish products is capable of detection using REIMS, a concept never previously reported.ConclusionsREIMS has been proven to be an innovative technique to help aid the detection of fish fraud and has the potential to be utilised by fisheries to conduct their own quality control (QC) checks for fast accurate results.

Specimen Fragmentation and Outcomes of Loop Electrosurgical Excision Procedures (LEEP) and Cold Knife Cone Biopsies (CKC) for Cervical Dysplasia

Specimen Fragmentation and Outcomes of Loop Electrosurgical Excision Procedures (LEEP) and Cold Knife Cone Biopsies (CKC) for Cervical Dysplasia

1094 Endoscopic Shears: An Alternative to an Insulated Tip Electrosurgical Knife for Zenker's Diverticular Repair, Stricturoplasty, and Endoscopic Submucosal Dissection

1094 Endoscopic Shears: An Alternative to an Insulated Tip Electrosurgical Knife for Zenker's Diverticular Repair, Stricturoplasty, and Endoscopic Submucosal Dissection

MP52-19 THE EXPERIENCE OF USING A DUAL CHANNELIZED FLEXIBLE CYSTOSCOPE WITH AN IMPACT SHOOTER FOR RESECTION OF BLADDER TUMORS IN HUMAN CADAVERS EMBALMED BY THIEL'S MODEL

You have accessJournal of UrologySurgical Technology & Simulation: Instrumentation & Technology I1 Apr 2017MP52-19 THE EXPERIENCE OF USING A DUAL CHANNELIZED FLEXIBLE CYSTOSCOPE WITH AN IMPACT SHOOTER FOR RESECTION OF BLADDER TUMORS IN HUMAN CADAVERS EMBALMED BY THIEL'S MODEL Shuichi Morizane, Toshihiro Maeda, Ryoma Nishikawa, Masashi Honda, Yuichiro Ikebuchi, Kazuya Matsumoto, Masaru Ueki, Naoya Masumori, Mineko Fujimiya, and Atsushi Takenaka Shuichi MorizaneShuichi Morizane More articles by this author , Toshihiro MaedaToshihiro Maeda More articles by this author , Ryoma NishikawaRyoma Nishikawa More articles by this author , Masashi HondaMasashi Honda More articles by this author , Yuichiro IkebuchiYuichiro Ikebuchi More articles by this author , Kazuya MatsumotoKazuya Matsumoto More articles by this author , Masaru UekiMasaru Ueki More articles by this author , Naoya MasumoriNaoya Masumori More articles by this author , Mineko FujimiyaMineko Fujimiya More articles by this author , and Atsushi TakenakaAtsushi Takenaka More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2017.02.1649AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Transurethral en bloc resection of bladder tumor with a dual channelized flexible cystoscope using an Impact Shooter in human cadavers embalmed by Thiel′s model. METHODS This study was approved by the institutional review board of Sapporo Medical University. Four human male cadavers (73 to 86 years old) embalmed by Thiel′s method were used as a model for performing ESD. A flexible cystoscope (CYF-200; OLYMPUS) was used to perform ESD (Fig. 1a). We used a transparent attachment with a tube of diameter 2.8-mm (Impact Shooter N type 6.0-mm diameter; Top Co.). It is designed for devices such as ESD knives and enables the endoscope to work like a dual channel scope (Fig. 1b). We used an electrosurgical knife (Dual Knife, 2.7-mm diameter; OLYMPUS), commonly used for gastrointestinal tract′s ESD (Fig. 1c). A circular area of 1.0-2.0-cm diameter was defined in the bladder and identified as the target area for resection (Fig.2a-c). RESULTS The ESD technique was applied into 5 places of bladder per cadaver. Although the target areas were successfully resected from the four cadavers (Fig.2d), one small bladder perforation occurred. In total 20 procedures, the median size of the resected pieces ex vivo was 1.4 cm (range 0.8-2.0 cm), and the median time taken to resect each target piece was 9.0 min (range 4.0–17.0 min). Endoscopic procedures of bladder using a flexible cystoscope with an Impact shooter was technically feasible in the human male cadavers. However, the handling of the tool was slightly difficult because of the poor flexibility of the additional attachment and the influence of the relative hardness of the urethra of cadavers as compared to healthy persons. CONCLUSIONS Transurethral ESD technique using a flexible cystoscope was considered technically feasible for the small bladder tumors. We hope that in the near future a new flexible cystoscope with dual and large caliber channels will be developed in order to facilitate ESD technique. © 2017FiguresReferencesRelatedDetails Volume 197Issue 4SApril 2017Page: e711-e712 Advertisement Copyright & Permissions© 2017MetricsAuthor Information Shuichi Morizane More articles by this author Toshihiro Maeda More articles by this author Ryoma Nishikawa More articles by this author Masashi Honda More articles by this author Yuichiro Ikebuchi More articles by this author Kazuya Matsumoto More articles by this author Masaru Ueki More articles by this author Naoya Masumori More articles by this author Mineko Fujimiya More articles by this author Atsushi Takenaka More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Treatment of recurrent esophageal stricture with an insulated-tip electrosurgical knife and mitomycin C

Treatment of recurrent esophageal stricture with an insulated-tip electrosurgical knife and mitomycin C

Phlegmonous esophagitis treated by endoscopic drainage

Phlegmonous esophagitis is a rare and sometimes fatal condition. Cases surgically treated have been reported previously; however, surgical approaches may be risky in the elderly. An 86-year-old woman presented with a sore throat and high fever after eating fish. She was first diagnosed with a deep cervical abscess, and conservative treatment was initially selected. However, her respiratory failure worsened, so emergent tracheostomy and surgical drainage were performed. Computed tomography showed intramural low-density lesions along the entire length of the esophagus and she was diagnosed with phlegmonous esophagitis. To avoid surgical intervention, endoscopic drainage was first attempted. Mucosal incision was made on the lower esophagus guided by endoscopic ultrasonography, using the insulated-tip electrosurgical knife. After the endoscopic drainage, her general health status improved, and the esophageal wall thickness was reduced. While some cases have recovered with conservative treatment, endoscopic drainage may be useful in certain patients.

Efficacy of deep biopsy for subepithelial lesions in the upper gastrointestinal tract.

IntroductionAccurate diagnosis of subepithelial lesions (SELs) in the gastrointestinal tract depends on a variety of methods: endoscopy, endoscopic ultrasound and different types of biopsy. Making an error-free diagnosis is vital for the subsequent application of an appropriate treatment.AimTo evaluate the efficacy of deep biopsy via the endoscopic submucosal dissection (ESD) technique for SELs in the upper gastrointestinal tract.Material and methodsIt was a case series study. Deep biopsy via the ESD technique was completed in 38 patients between November 2012 and October 2014. Thirty-eight SELs in the upper gastrointestinal tract of varying size (very small ≤ 1 cm, small 1–2 cm and large ≥ 2 cm) by means of the ESD technique after an incision with an electrosurgical knife of the overlying layers and revealing a small part of the lesion were biopsied under direct endoscopic view.ResultsDeep biopsy via the ESD technique was diagnostic in 28 of 38 patients (73.3%; 95% CI: 59.7–89.7%). The diagnostic yield for SELs with a clear endophytic shape increased to 91.3%. An evident endophytic appearance of a subepithelial lesion, the mean number of biopsied samples (6.65 ±1.36) and the total size in length of all samples per case (19.88 ±8.07 mm) were the main criteria influencing the positiveness of deep biopsy in the diagnostic group compared to the nondiagnostic one (p = 0.001; p = 0.025; p = 0.008).ConclusionsDeep biopsy via the ESD technique is an effective and safe method for the diagnosis of SELs especially with a clear endophytic appearance in a large number of biopsied samples.

An innovative procedure of laparoscope combined with endoscopy for gastrointestinal stromal tumor resection and cholecystectomy: A case report and literature review.

The present study reports a novel approach to laparoscopic and endoscopic cooperative surgery for gastric gastrointestinal stromal tumor (GIST) resection and cholecystectomy, and conducts a review of the associated literature. The novel surgical procedure was performed on one patient who was diagnosed with a GIST and cholecystic polypus. The GIST was resected using an insulation-tipped diathermic electrosurgical knife under the guide of an endoscope. Subsequently, a cholecystectomy was performed by inserting two more 5-mm trocars and instruments transumbilically, guided using an endoscope. The tumor and the gallbladder were exteriorized using a peroral approach and the incision lining of the stomach was sutured laparoscopically. The procedure was successfully performed and the patient experienced no discomfort during the 5-year follow-up. In conclusion, the present study demonstrates that laparoscopic and endoscopic cooperative surgery is feasible and would be an ideal choice for invisible abdominal scar surgery, in particular for multi-visceral resection.

Metabolomics continues to expand: highlights from the 2015 metabolomics conference

The 11th annual international conference of the Metabolomics Society, held in San Francisco from June 29th to July 2nd 2015, lived up to its reputation as the highlight of the metabolomics calendar. With over 700 oral and poster presentations and almost 1000 attendees, this was the largest metabolomics conference to date. The conference was opened by an inspiring demonstration of the role of metabolomics in the future of personalized medicine by Mike Snyder (Stanford University). Professor Snyder described a comprehensive systems approach to personalized medicine, combining longitudinal measurements of the metabolome, genome, transcriptome, proteome and microbiome in response to lifestyle changes. The presentation gave a snapshot of the way that mature omics technologies could enable systems medicine to predict and monitor health and disease. Another highlight was the presentation of iKnife technology by Zoltan Takats (Imperial College London). This unique technology involving rapid evaporative ionization mass spectrometry coupled to an electrosurgical knife demonstrates the implementation of metabolomics-based tissue typing in real time, providing a more rapid alternative to conventional histological tests during cancer surgery. A feature of this conference was the excellent work presented by the younger members of the metabolomics community. Students and early career scientists gave over 40 % of the oral presentations, and hundreds of high quality posters. Over 60 young researchers received travel awards from the U.S. National Institutes of Health (NIH), industry sponsors, academic institutions and the Metabolomics Society, making this large turnout of young scientists possible. The coveted Metabolomics Society Student Prize was awarded to Jonas Zierer (Kings College London). Jonas identified metabolic biomarkers, including gamma-glutamyl peptides and a lyso-PI lipid, that were associated with leukocyte telomere length in a large twin cohort. This study promises to open new avenues of investigation into the causes and consequences of the aging process. The inaugural Early Career award, for scientists within 5 years of completing their PhD, was won by Andrew Palmer (EMBL, Germany). Andrew described a novel approach to annotate metabolites from MALDI imaging with high resolution MS analyses, linking biological pathways with the distribution of metabolites observed in spatial metabolomics experiments. This approach allowed significant reduction of the size of imaging MS data files while maintaining biologically interpretable information about differential metabolism between cells in a population.

Conization Using an Electrosurgical Knife for Cervical Intraepithelial Neoplasia and Microinvasive Carcinoma.

ObjectiveThe aim of the present study was to evaluate the incidences of margin involvement, disease relapse, and complications in patients who had undergone conization using an electrosurgical knife (EKC) for cervical intraepithelial neoplasia (CIN) or microinvasive carcinomas (micro-CAs).Materials and MethodsA retrospective case series analysis was performed with a total of 1359 patients who underwent EKC in Fudan University Shanghai Cancer Center between June 2004 and July 2010.ResultsThe median age of the patients was 39 years old (range: 19-72). Conization revealed the presence of CIN in 1113 (81.9%) patients, micro-CA in 72 (5.3%) patients and invasive carcinomas in 44 (3.2%) patients. The remaining 130 (9.6%) patients were free of diseases in the cone specimens. Positive surgical margins, or endocervical curettages (ECCs) were found in 90 (7.6%) patients with CINs or micro-CAs. Three factors were associated with positive margins and ECCs and included age (>50 years; odds ratio (OR), 3.0, P<0.01), postmenopausal status (OR, 3.1, P<0.01) and microinvasive disease (OR, 2.7, P<0.01). One thousand and eighty-nine (92.0%) patients were followed-up regularly for a median follow-up duration of 46 months (range: 24-106 months). Disease relapse was documented in 50 (4.6%) patients. Eighty-two (6.0%) cases experienced surgical complications that needed to be addressed, including early or late hemorrhages, infections, cervical stenosis, etc.ConclusionsOur patients demonstrated that EKC was an alternative technique for diagnosis and treatment of CIN or micro-CAs with relatively low rate of recurrence and acceptable rate of complications. A randomized clinical trial is warranted to compare EKC, CKC and LEEP in the management of CIN or micro-CA.

Submucosal endoscopy with mucosal resection (SEMR): a new hybrid technique of endoscopic submucosal balloon dissection in the porcine rectosigmoid colon

We developed a technique, submucosal endoscopy with mucosal resection (SEMR) intended to make endoscopic submucosal dissection easier and safer. With this technique, the submucosal layer is balloon dissected in lieu of electrosurgical knife dissection. The aim of this study was to further evaluate SEMR in the porcine rectum and colon. Targeted sites in the rectum and the distal colon were marked by spot coagulation. Submucosal fluid cushions (SFC) were created followed by a circumferential mucosal incision. After isolation of the targeted mucosa, balloon dissection was initiated. The balloon catheter was inserted deep into SFC and the inflated balloon repeatedly pulled back toward the endoscope tip to disrupt the submucosa. Residual strands of submucosa were cut. Dissection difficulty scores (DDS) were used using a visual analogue scale ranging from 0 to 5 (failed). The entire study period was divided into three periods (first period, pigs 1-10; second period, pigs 11-20; third period, pigs 21-30). Sixty lesions in 30 pigs were resected using SEMR. The en block resection rate was 95%. There were three incomplete resections, two as a result of an errant site location and one as a result of a floppy prototype balloon catheter tip. The median resected size, procedure time, and DDS were 6.0 cm, 25 min, and 1. All three failed cases occurred in first period. The procedure time in third period was significantly shorter than the second period (P = 0.0017). The DDS in first period was significantly higher than the second (P = 0.0024) and third (P = 0.0155) periods. Two perforations, one muscularis propria catheter perforation, and one mucosal perforation were observed (3.3%). Large mucosal target sites in the rectum and distal colon could be safely removed en bloc by means of a hybrid technique, SEMR, with blunt submucosal balloon dissection.

Endoscopic submucosal dissection for residual early gastric cancer after endoscopic submucosal dissection

Endoscopic submucosal dissection (ESD) has become a standard treatment for early gastric cancer (EGC). 1-12 ESD involves circumferential mucosal incision and direct submucosal dissection, making it possible to resect en bloc even large tumors with endoscopically clear margins in any part of the stomach. The reported incomplete ESD resection rate is 7.4% to 26.3%, 1,2,13-19 and the reported local recurrence rate after ESD is 0% to 3%. 1,18-20 Incomplete resection leading to recurrent cancer in the stomach therefore continues to be problematic. Additional treatment is necessary in patients with incompletely resected lesions. We have reported ESD for residual/local recurrent EGC after EMR to be a safe, minimally invasive, effective procedure. 21 There are few published reports on the treatment of local recurrences of EGC after ESD, and it is difficult to carry out a second ESD because of scar formation resulting from the initial ESD. Between June 2005 and August 2012, we performed a second ESD in 12 patients with residual EGC lesions after having been treated with ESD, and we conducted a retrospective evaluation of the safety and efficacy of this method of treatment.

A Comparison of Loop Electrosurgical Excision Procedure and Cold Knife Cone

A Comparison of Loop Electrosurgical Excision Procedure and Cold Knife Cone

Rigid and flexible endoscopic rendezvous in spatium peritonealis may be an effective tactic for laparoscopic megasplenectomy: significant implications for pure natural orifice translumenal endoscopic surgery

We recently experienced 10 patients with cirrhosis who underwent laparoscopic splenectomy. A portion of these patients underwent dissection with a flexible endoscope in the peritoneal cavity. This pilot study mainly focused on the technical aspects and immediate results. From November 2009 to September 2010, 10 patients with cirrhosis and hypersplenism were entered into this pilot study. They were indicated to undergo laparoscopic splenectomy to treat portal hypertension and to facilitate initiation and completion of either interferon therapy for liver cirrhosis or anticancer therapy for hepatocellular carcinoma. To dissect the upper end of the gastrosplenic ligament and the marginal region between the left diaphragm and upper pole of the spleen, a flexible single-channel endoscope was introduced into the peritoneal cavity simultaneously with the use of a rigid laparoscope. Dissection with the flexible endoscope in the peritoneal cavity was performed using an insulation-tipped electrosurgical knife through the channel of the flexible endoscope. The flexible endoscope offered a magnified operative view, a water-jet lens cleaner, and a powerful lavage and suction capability. The upper end of the gastrosplenic ligament and the marginal region between the left diaphragm and upper pole of the spleen were easily seen, and dissection of these critical regions was smoothly conducted with articulation of the tip of the flexible endoscope, even in patients with splenomegaly. No patient experienced major intraoperative complications or required conversion to open surgery. Dissection with a flexible endoscope in the peritoneal cavity may be an effective tactic for laparoscopic megasplenectomy, and significant implications for pure natural orifice translumenal endoscopic surgery have been raised. Although future randomized controlled prospective studies are needed to confirm these findings, surgeons might find this to be a typical example of an appropriate strategy for high-risk patients.

放射電磁波を利用した電気メス使用中点検法の検討

放射電磁波を利用した電気メス使用中点検法の検討

The Electrosurgical Knife in an Optimized Intermittent Cutting Mode for the Endoscopic Treatment of Benign Web-like Tracheobronchial Stenosis

The established endoscopic treatment of web-like tracheobronchial stenosis is laser vaporization, but the appearance on the market of a new cutting mode with a lower coagulation effect has been proposed as an alternative to laser due to less injury to the tissue. Objectives To study the clinical and functional consequences, as well as the side effects of this technique. Afterwards, we investigated whether the use of an electrosurgical knife with this technique is as effective and convenient as an ND-YAG-laser. Patients and methods Between March 2005 and July 2007, included for study were 22 patients who had undergone 34 interventional bronchoscopy procedures with the VIO-300-D radiofrequency system, using a mode of the Endo-cut I program in conjunction with the reusable knife electrode. Results All of the patients treated (100%) presented improvements in their symptoms, in the tracheobronchial lumen diameter and in lung function, which were statistically significant. Symptom-free time was 157 ± 93 days. There was an overall decrease observed in mean obstruction ( P< .001 ). Improvements in FVC ( P=.01), raw ( P=.0016) and RV/TLC ( P=.01) were significantly significant. Less than 50% of the patients needed a second intervention. These patients were compared retrospectively with a similar group of 22 patients treated with Nd-YAG laser. The follow-up analysis showed that only 18% (4/22) of the patients treated with this new technique presented fibrin, compared with 41% (9/22) of those treated with laser therapy ( P < .001). Conclusion The use of this technique is effective for the treatment of benign web-like tracheobronchial stenosis as all the patients showed clinical and functional improvement, and less than 50% required a second intervention. In comparison with laser therapy, an advantage of this technique is that less fibrin is produced, probably due to the reduced anti-coagulation effect.

Tratamiento endoscópico de las estenosis benignas traqueobronquiales tipo web-like con el bisturí endobronquial en combinación con un programa de corte optimizado

The established endoscopic treatment of web-like tracheobronchial stenosis is laser vaporization, but the appearance on the market of a new cutting mode with a lower coagulation effect has been proposed as an alternative to laser due to less injury to the tissue. Objectives To study the clinical and functional consequences, as well as the side effects of this technique. Afterwards, we investigated whether the use of an electrosurgical knife with this technique is as effective and convenient as an ND-YAG-laser. Patients and methods Between March 2005 and July 2007, included for study were 22 patients who had undergone 34 interventional bronchoscopy procedures with the VIO-300-D radiofrequency system, using a mode of the Endo-cut I program in conjunction with the reusable knife electrode. Results All of the patients treated (100%) presented improvements in their symptoms, in the tracheobronchial lumen diameter and in lung function, which were statistically significant. Symptom-free time was 157 ± 93 days. There was an overall decrease observed in mean obstruction ( P < .001). Improvements in FVC ( P = .01), Raw ( P = .0016) and RV/TLC ( P = .01) were significantly significant. Less than 50% of the patients needed a second intervention. These patients were compared retrospectively with a similar group of 22 patients treated with Nd-YAG laser. The follow-up analysis showed that only 18% (4/22) of the patients treated with this new technique presented fibrin, compared with 41% (9/22) of those treated with laser therapy ( P < .001). Conclusion The use of this technique is effective for the treatment of benign web-like tracheobronchial stenosis as all the patients showed clinical and functional improvement, and less than 50% required a second intervention. In comparison with laser therapy, an advantage of this technique is that less fibrin is produced, probably due to the reduced anti-coagulation effect.

A Case of Corrosive Injury-Induced Pharyngeal Stricture Treated by Endoscopic Adhesiolysis Using an Electrosurgical Knife

Here, we report a case of corrosive injury-induced pharyngeal stricture in a 69-year-old female, which was successfully treated with endoscopic adhesiolysis using an electrosurgical knife. The patient had ingested sodium hydroxide in an attempted suicide, and immediate endoscopy revealed corrosive injuries of the pharynx, esophagus, and stomach. When a liquid diet was permitted, she complained of nasal regurgitation of food. Follow-up endoscopy revealed several adhesive bands and a web-like scar that did not allow passage of the endoscope into the hypopharyngeal area. For treatment of the hypopharyngeal stricture, the otolaryngologist attempted to perform an excision of the fibrous bands around the esophageal inlet using microscissors passed through an esophagoscope, but this procedure was not effective. We then dissected the mucosal adhesion and incised the adhesive bands using an electrosurgical knife. After this procedure, nasal regurgitation of food no longer occurred. To our knowledge, this case is the first report of endoscopic adhesiolysis with an electrosurgical knife in a patient with a corrosive injury-induced pharyngeal stricture.