Cochlear effects of mesna application into the middle ear

The assesment of intraoperative use of mesna in canal wall-up cholesteatoma surgery - preliminary report

<b>Introduction:</b> Surgery is still the method of choice in chronic otitis media with cholesteatoma. Except for some specific clinical situations, classic canal wall up technique (CWU), remains a gold standard as a primary treatment in most departments. Unfortunately, the risk of recurrence in such an approach is estimated at 9 to even 70%. This fact prompts researchers to look for ways to reduce those unfavourable statistics. One of the recognized methods supporting the removal of cholesteatoma is the intraoperative use of mesna (sodium 2-mercaptoethanesulfonate). This synthetic sulphur compound disrupts disulfide bridges in polypeptide chains, thanks to which it facilitates matrix preparation.</br></br> <b>Aim:</b> To evaluate the effect of intraoperative use of mesna on the treatment outcomes in patients with chronic otitis media with cholesteatoma operated on by means of the canal wall up technique (CWU).</br></br> <b>Material and methods:</b> 459 surgical reports of patients with middle ear cholesteatoma were analyzed. In total, 52 adult patients with no history of previous ear surgery operated on by means of the CWU technique by the same experienced otosurgeon with all follow-up data available were included in the study. Twenty-six were operated on with the use of mesna (mesna group) and 26 by means of the classic CWU technique (control / no-mesna group). There were 28 women and 24 men with a mean age of 41 years.</br></br> <b>Main Outcome Measure(s):</b> Postoperative hearing results and cholesteatoma recidivism rate.</br></br> <b>Results:</b> Overall recidivism rate was 21.15 %. It was higher in the no-mesna (26.9%) than in the mesna group (15.4%) - although the outcomes were better in the mesna group, the difference was not statistically significant (P = 0.49715). Hearing gain was better in the mesna than in the no-mesna group (10 dB vs 7 dB), but the difference was not statistically significant (P = 0.20089).</br></br> <b>Conclusions:</b> Our preliminary results show that mesna reduces recidivism rates in patients with cholesteatoma. Further study with the analysis of a larger group of patients is needed to prove it statistically.

Epigenetic Regulation as a New Therapeutic Target for Middle Ear Cholesteatoma

HYPOTHESIS

To evaluate the effectiveness of the menin-MLL inhibitor, MI503, as a conservative treatment of middle ear cholesteatoma (cholesteatoma) in a mouse model and to confirm its safety profile regarding auditory function in vivo.

BACKGROUND

Cholesteatoma is a mass formed by the keratinizing squamous epithelium in the tympanic cavity and/or mastoid and subepithelial connective tissue and by the progressive accumulation of keratin debris with/without a surrounding inflammatory reaction. Although the main treatment is surgical therapy, the techniques to prevent recurrence remain a critical area of research. Recently, the use of MI503 in experiments resulted in the inhibition of the growth of cholesteatoma in vivo under histone modification.

METHODS

After cholesteatoma was induced in ICR mice (n = 7) by keratinocyte growth factor expression vector transfection, MI503 (50 μM) or phosphate-buffered saline was topically injected for 14 days. The effects of MI503 against cholesteatoma were analyzed by micro-computed tomography images. For the in vivo ototoxicity study, a single intratympanic injection of MI503 (50 or 500 μM) or phosphate-buffered saline (n = 4 each) was done in the ICR mice. An auditory brainstem response was performed at days 0, 1, and 14. For morphological analysis, immunostaining for Phalloidin/F-actin and Myo7a was performed.

RESULTS

MI503 reduced keratinocyte growth factor-induced cholesteatoma in vivo (4 of 4 [100%]). No difference was found in the mean variation of the average of the auditory brainstem response thresholds between the three groups in the in vivo ototoxicity study, thus confirming its safety profile regarding auditory function. MI503 does not demonstrate any deleterious effects on murine hair cells when assessed by immunostaining.

CONCLUSION

These findings demonstrate an encouraging safety profile for the use of menin-MLL inhibitor for the conservative treatment of cholesteatoma.

Inhibitory effect of mesna and 5-fluorouracil on propylene glycol-induced cholesteatoma in rats

Objective

The aim of this study was to investigate the inhibitory effect of different doses of sodium-2-mercaptoethanesulphonate (MESNA) and 5-fluorouracil on cholesteatoma formation.

Methods

Fifty-six Wistar albino male rats were divided into seven groups with eight rats in each. On the first, eighth and fifteenth days, 0.2 ml of saline was administered to the group 1 (control group), and propylene glycol to induce cholesteatoma the other groups. On the 22^nd day of the study, 0.2 ml saline was given to Group 1 and Group 2. Groups 3 to 7 were treated with 0.2 ml 100% MESNA, 0.2 ml 50% MESNA, 0.2 ml 20% MESNA, 0.2 ml 5-fluorouracil and 0.1 ml 100% MESNA plus 0.1 ml 5-fluorouracil, respectively, with all applications performed by intratympanic injection.

Results

Significant differences were found between Group 1 and all other groups except Group 3. Significant differences were also found between Group 3 and Groups 2, 5 and 6 (P < 0.05).

Conclusions

According to the results of this study, experimental cholesteatoma induced with propylene glycol may be inhibited by MESNA at 100% concentration.

Changes in biofilm in chronic cholesteatomatous otitis media in children following the application of sodium 2-mercaptoethanesulfonate (MESNA)

BACKGROUND

Pediatric cholesteatoma is a clinically challenging disease entity. Its biological behavior in the pediatric population differs from its behavior in adult population in terms of aggressiveness and recurrence. Several studies have shown the presence of biofilms associated with cholesteatoma that hinder the management and eradication of the infection. This led is to study the use of non-antimicrobial treatments impacting on the structure or composition of biofilms.

OBJECTIVE

To evaluate the changes that occur in the biofilm of cholesteatoma in pediatric patients after the application of sodium 2-mercaptoethanesulfonate (MESNA).

METHODS

A pilot study of 10 pediatric patients, with a median age of 10 years and a diagnosis of cholesteatomatous chronic otitis media, who underwent surgery for primary or revision mastoidectomy in the Otorhinolaryngology Service of the Hospital Infantil de México Federico Gómez between January 2016 and May 2017. During the surgery, basal samples of cholesteatoma and tissue were taken after topical application of 4% MESNA for 10 min. The samples were then processed for confocal laser microscopy.

RESULTS

In all samples structures compatible with bacterial biofilms were identified. The most relevant finding was the changes in the structure of the biofilm after the application of MESNA, such as disintegration and separation of the underlying tissue.

CONCLUSIONS

This is the first study that showing changes associated with cholesteatoma in the structure of the bacterial biofilm after the application of MESNA. The observed disintegration of cholesteatoma biofilm ultrastructure could aid in the management of the chronic infection associated with cholesteatoma.

Different concentrations of mesna application have an effect on the internal ear?

OBJECTIVE

The use of Mesna as a chemical dissector in higher concentrations may reduce the length of time of operation by providing more effective dissection as well as being used in otologic pathologies such as tympanosclerosis. In this study, it was aimed to assess the effect of Mesna on the internal ear, which was applied intra-tympanically in higher concentrations than the conventional use.

METHODS

Twenty-four female rats were included in our study. The rats were randomly divided into three groups (Group 1: Mesna 50%, Group 2: Mesna 100%, Group 3: Saline). At the beginning of the study, DPOAE and ABR measurements were carried out on every rat on days 7 and 14. At the end of the study, cochleas of the rats were excised and histopathological assessments were carried out.

RESULTS

Basal values and DPOAE and ABR values on day 7 and 14 of Group 1, Group 2, and Group 3 were similar to each other. No significant difference was detected among the three groups in the histopathological assessment carried out at the end of the study.

CONCLUSION

It was revealed by audiological and histopathological parameters that the use of Mesna at 50% and 100% concentrations did not create toxicity effects on the internal ear. Mesna would be more effective by being used in higher concentrations in audiological surgeries, that its duration of operation world reduce and could being used in different indications including tympanosclerosis.

Electrophysiological and Histopathological Evaluation of Effects of Sodium-2 Mercaptoethanesulfonate Used for Middle Ear Surgery on Facial Nerve Functions

OBJECTIVE

Sodium-2-mercaptoethanesulfonate (MESNA) is widely used in medicine because of its antioxidant and mucolytic effects. In recent years, it has been used in otologic surgery. Because it cleaves disulfide bonds, it is used to easily dissect the epithelial matrix in cholesteatoma and atelectasis. In this study, we hypothesized that MESNA does not have any toxic effect on the facial nerve, and the effects of MESNA on the facial nerve were examined histologically and electrophysiologically.

MATERIALS AND METHODS

Twenty Wistar albino rats were used. Groups A and B were designated as the control and sham groups, respectively. The animals in groups C and D were administered 20% and 50% of MESNA solution, respectively, after the facial nerve was exposed in the parotid region. Electromyography (EMG) measurements were performed preoperatively and postoperatively at 4 weeks. The animals were subsequently euthanized; facial nerve samples were taken for histopathological examination.

RESULTS

When EMG parameters were compared within and between each group, preoperative and postoperative results were not statistically significantly different. Histopathological examination showed that MESNA did not cause any inflammation, granulation tissue, or foreign body reaction.

CONCLUSION

To the best of our knowledge, the effects of MESNA on facial nerve functions have not been investigated. In this study, the effects of MESNA after direct application to the facial nerve were examined electrophysiologically and histologically, and it was determined that MESNA did not cause any toxic effects. It was concluded that MESNA can, therefore, be safely used during middle ear surgery.

Screw migration and oesophageal perforation after surgery for osteosarcoma of the cervical spine

Background

Even though internal fixation has expanded the indications for cervical spine surgery, it carries the risks of fracture or migration, with associated potential life threatening complications. Removal of metal work from the cervical spine is required in case of failure of internal fixation, but it can become challenging, especially when a great amount of scar tissue is present because of previous surgery and radiotherapy.

Case presentation

We report a 16 year old competitive basketball athlete who underwent a combined anterior and posterior approach for resection of an osteosarcoma of the sixth cervical vertebra. Fourteen years after the index procedure, the patient eliminated spontaneously one screw through the intestinal tract via an oesophageal perforation and developed a severe dysphagia. Three revision surgeries were performed to remove the anterior plate because of the great amount of post-surgery and post-irradiation fibrosis.

Conclusions

Screw migration and oesophageal perforation after cervical spine surgery are uncommon potentially life-threatening occurrences. Revision surgery may be challenging and it requires special skills.

The Effects of MESNA on the Facial Nerve, an Experimental Animal Study

OBJECTIVE

MESNA (Sodium-2-mercaptoethanesulfonate) is a mucolytic substance that is used for chemically assisted tissue dissection in various surgical operations. The aim of this study was to address the issue of possible neurotoxicity from topical administration of MESNA solution on the facial nerve. We used different concentrations of MESNA solution and evaluated their effects on facial nerve by histopathological and functional analysis.

MATERIALS AND METHODS

These groups were the saline administered group (control) (3 rats, 6 facial nerves), the 25% MESNA solution group (3 rats, 6 facial nerves), and the 100% MESNA solution group (3 rats, 6 facial nerves). Under general anesthesia (ketamine 150 mg/kg, xylocaine 4 mg/kg), the bilateral facial nerves of rats were dissected. The saline, 25% MESNA, and 100% MESNA solutions. Facial nerve functions of the rats were evaluated using mustachewhisker and blink reflex scores at day 20 days. On day 20, the rats were sacrificed and the buccal and marginal mandibular branches of the facial nerve were removed. The specimens were examined in terms of inflammation, granulation tissue, and foreign body reaction formation around the nerve. The functional and histopathological changes on facial nerves were compared between groups.

RESULTS

Mustache and blink reflex scores of the rats were 5 (normal) in both the control and study groups. There were no statistically significant differences between the three groups in terms of facial nerve functions (p=1.00). On histopathologic examination, the 25% and 100% MESNA groups had significantly more inflammation compared with the control group (p=0.038 and p=0.007, respectively). There were no statistically significant differences between the 25% and 100% MESNA groups in term of inflammation (p > 0.05). There were no statistically significant differences between the three groups in terms of foreign body reaction formation (p > 0.05).

CONCLUSION

Topical administration of MESNA solution onto the facial nerve causes increased inflammation in both the 25% and 100% concentrations. Nevertheless, it does not cause any facial nerve dysfunction.

Failed back surgery syndrome: a new strategy by the epidural injection of MESNA

PURPOSE

Evaluate the efficacy and safety of MESNA (sodium 2-mercaptoethanesulfonate) injection into the epidural space in the FBSS.

METHODS

We designed a prospective phase II longitudinal study. Six consecutive patients were enrolled. Patients underwent one peridural injection per week for 3 weeks. NRS and ODI were investigated before and 48 h after injections, and at 1 week, 1 month and 2 months after the last procedures. Opioids intake is investigated before procedures and 1 week, 1 month and 3 months after the last procedures. Lumbosacral MRI is performed before the first procedure, at the end and 3 months after the last procedures.

RESULTS

From baseline, at 3 months, NRS in standing, sitting and lying position improved, respectively, of 34.29, 30.56 and 26.47%; ODI improved of 20.3%; the average decrease in morphine intake was 20.54%. No difference in MR images was found. Conclusions Our preliminary results suggest that MESNA might be an efficacy alternative to common practice.

Single dose intratympanic mesna application inhibits propylene glycol induced cholesteatoma formation

Objective:

Mesna (i.e. sodium 2-mercaptoethanesulfonate; C2H5NaO3S2) has been used in otological surgery such as cholesteatoma dissection and tympanic membrane lateralisation in atelectatic ears. However, this study aimed to investigate its effect on cholesteatoma formation.

Methods:

A total of 20 Wistar rats were divided into two groups of 10 animals. The right and left ears of control animals were treated with saline (saline control group; n = 10 ears) and propylene glycol plus saline (propylene glycol control group; n = 10 ears), respectively. In the mesna group, both ears were treated with propylene glycol plus mesna (n = 20 ears). On days 1, 8 and 15, the saline control group had intratympanic injections of 0.2 ml saline and the propylene glycol control and mesna groups had intratympanic injections of 0.2 ml 100 per cent propylene glycol. On day 22, the propylene glycol control group had a single intratympanic injection of 0.2 ml saline and the mesna group had a single intratympanic injection of 10 per cent mesna. Animals were killed 12 weeks after the last injection and the temporal bones were sent for histopathological evaluation.

Results:

The cholesteatoma formation rate was 88 per cent in the propylene glycol control group, but was significantly lower in the mesna group (p = 0.01). There were no significant differences in granulation tissue formation (p = 0.498), cyst formation in the bulla (p = 0.381), fibrosis (p = 0.072) and epithelial hyperplasia (p = 0.081) among experimental groups.

Conclusion:

Intratympanic propylene glycol administration is an effective method of promoting experimental cholesteatoma formation. Administration of a single dose of intratympanic mesna inhibited cholesteatoma formation in an animal model.

The effects of sodium-2-mercaptoethanesulfonate application on the neural and neurovascular tissues: An experimental animal study

BACKGROUND

Sodium-2-mercaptoethanesulfonate (MESNA) is a protective agent that is also used as "a chemical dissector" in various surgical fields. The aim of this study is to evaluate the toxic effects of MESNA on neural and neurovascular structures based on a morphological analysis and examine its safety in neurotological applications.

METHODS

Three groups of guinea pigs were used as subjects. MESNA solution (50 and 100%) and saline solution were applied to the subarachnoid space over the brain tissue via a middle fossa approach of study and control groups, respectively. Effects of MESNA were assessed by means of light microscope. McNemar Chi-square test was used to evaluate the histopathological findings. Statistical significance of P < 0.05 was taken as criterion.

RESULTS

No morphological changes were observed on vascular and neural structures in the study groups in both concentrations, compared to the control group.

CONCLUSIONS

On a morphological basis, a single application of MESNA does not cause any morphological changes that indicate a toxicity in neural and neurovascular structures.

Techniques to reduce blood loss during open myomectomy: a qualitative review of literature

Open myomectomy is the most adopted surgical strategy in the conservative treatment of uterine fibroids. According to several studies, the likelihood that a woman could develop uterine myomas is estimated around 75% by the age of 50. Open myomectomy is nonetheless a complicated surgery in terms of blood loss and need for transfusion. Many strategies have been published with the aim of limiting intra and post-operative bleeding complications. The scope of this review is to describe in detail the different techniques reported in literature focusing on their validity and safety.

Acquired middle ear cholesteatoma in children with cleft palate: experience from 18 surgical cases

OBJECTIVES

To review an institutional experience with the surgical management of middle ear cholesteatoma in children with cleft palate.

MATERIALS AND METHODS

We analyzed retrospectively 18 children diagnosed with cleft palate who underwent surgery for acquired middle ear cholesteatoma between 2000 and 2007. The following data were recorded: age, sex, history of ventilation tube insertion, status of the contralateral ear, cholesteatoma location and extension, and surgical technique involved. Cholesteatoma recidivism, stable mastoid cavity and hearing levels were the main outcomes measured.

RESULTS

Follow-up ranged from 5 to 12 years (mean 8 years). Twelve children underwent planned staged canal wall up mastoidectomy: a residual cholesteatoma was found and removed during the second-look procedure in 2 ears (16.6%); two children (16.6%) showed a recurrent cholesteatoma and required conversion to canal wall down mastoidectomy. A modified Bondy technique was chosen in two children with an epitympanic cholesteatoma with an intact tympano-ossicular system, while in the remaining four subjects a canal wall down mastoidectomy was performed because of an irreparable erosion of the postero-superior canal wall: no cases of recurrent cholesteatoma were observed in these 6 children; revision mastoidectomy was needed in one patient for cavity granulation. A postoperative air-bone gap result of 0-20dB was achieved in 11 children (61.1%); in 5 cases (27.7%) postoperative air-bone gap was between 21 and 30dB, while in 2 (11.1%) was >30dB. Bone conduction thresholds remained unaffected in all cases.

CONCLUSIONS

Our results indicate that most cleft palate children with cholesteatoma can be managed with a canal wall up mastoidectomy with low complication rates. In extensive disease with large erosion of the canal wall as well in presence of a retraction pocket in the contralateral ear, a canal wall down mastoidectomy should be considered. In epitympanic cholesteatomas with an intact tympano-ossicular system and mesotympanum free of disease, the modified Bondy procedure is an effective surgical option. As in the general pediatric population, improvement or preservation of hearing can be obtained in most patients.

Effectiveness of MESNA on the success of cholesteatoma surgery

IMPORTANCE

It is important that chronic otitis media with cholesteatoma be treated successfully in patients to protect them from having repeated surgeries with related surgical co-morbidities and hearing loss.

OBJECTIVE

To evaluate the effectiveness of MESNA usage on the residual cholesteatoma rates of the patients who underwent surgery due to chronic otitis media with cholesteatoma.

DESIGN

Retrospective single-institution study of a prospectively collected database.

SETTING

Tertiary University Hospital.

PARTICIPANTS

Nine hundred and thirty-four patients underwent surgery due to chronic otitis media between September 2000 and March 2012 by the same surgeon. One hundred and forty-one cases out of 934 patients were selected who had cholesteatoma for the study. These randomly selected 141 cases were divided into two groups as follows: I. Forty-six cases were applied MESNA (Sodium 2-mercaptoethanesulfonate) intraoperatively, and II. Ninety-five cases were not applied MESNA intraoperatively. The cases that were followed-up at least one year were included in this study.

INTERVENTION

MESNA (Ureomitexan, MESNA, Baxter oncology, Germany) was diluted with saline (20% MESNA and 80% saline) that was applied, and then a waiting period of approximately 5 min followed to start to dissect cholesteatoma matrix.

MAIN OUTCOMES AND MEASURES

Residual cholesteatoma rates between intraoperative MESNA, a disulfide bond breaking chemical agent, applied and MESNA non-applied cases in the postoperative follow-up period were compared for the success of the surgery.

RESULTS

MESNA was used in 46 patients out of 141 cases intraoperatively. Twenty-four of these patients underwent CWD (canal wall down), and twenty-two patients underwent CWU (canal wall up) mastoidectomy. For the other 95 subjects, 56 patients with CWD and 39 with CWU mastoidectomy, MESNA was not applied. Residual cholesteatoma rates were found to be significantly higher in MESNA non-applied group than MESNA applied group (p<0.05). Residual cholesteatoma rates between CWD and CWU mastoidectomy procedures were not statistically significant (p>0.05).

CONCLUSIONS AND RELEVANCE

MESNA application that breaks disulfide bonds in the structure of the matrix in cholesteatoma surgery may assist the elimination of the disease, and increase surgical success by facilitating the elevation of the epithelium. Thereby, it causes a decrease in the possibility of remaining residual epithelium after surgery, which decreases the need for second-look surgery.

TRIAL REGISTRATION

The retrospective research protocol was approved by the Inonu University Clinical Research Ethics Committee.

REGISTRATION NUMBER

………

A double-blind, block-randomized, placebo-controlled trial to identify the chemical assistance effect of mesna submucosal injection for gastric endoscopic submucosal dissection

BACKGROUND

Previous animal studies and a pilot clinical trial demonstrated that submucosal injection of a thiol compound called mesna could chemically soften connective tissues and thus facilitate endoscopic submucosal dissection (ESD).

OBJECTIVE

To evaluate whether mesna injection could reduce procedural times for gastric ESD.

DESIGN

Double-blind, block-randomized, controlled trial.

SETTING

University hospital.

PATIENTS

A total of 101 patients with superficial gastric cancer indicated for ESD were enrolled and randomly assigned to either the mesna or control (saline solution) group.

INTERVENTION

Traditional ESD was performed with a single bolus injection of mesna or saline solution.

MAIN OUTCOME MEASUREMENTS

Time for submucosal dissection (TSD).

RESULTS

En bloc resection was achieved for all lesions in the mesna group (53/53) and 51 of 52 lesions (98.08%) in the control group. TSD was not statistically different between the groups (18.62 ± 13.9 [mean ± SD] minutes for the mesna group and 24.58 ± 24.55 [mean ± SD] minutes for the control group; P = .128), and there were fewer time-consuming cases (times over 30 minutes) in the mesna group compared with controls (7/53 vs 15/52; P = .049). Multivariate regression analysis demonstrated that use of mesna, specimen size, and the presence of fibrous scars were significantly correlated with TSD (P < .05).

LIMITATIONS

Single-center study.

CONCLUSION

TSD was not significantly different between the mesna and control injection groups, but multivariate analysis indicated that mesna injection reduced procedural challenges associated with the submucosal dissection. (

CLINICAL TRIAL REGISTRATION NUMBER

UMIN000003786.).

Surgical treatment of labyrinthine fistula in cholesteatoma surgery

Objective/Hypothesis: Evaluate the treatment of labyrinthine fistula in a large series of middle ear cholesteatomas.

Study Design: Case series in a tertiary referral center.

Methods: Between January 2001 and December 2007, 361 ears affected by mastoid and middle ear cholesteatoma were operated at our institution. The incidence of labyrinthine fistula, preoperative and postoperative hearing function, preoperative symptoms, type of surgery, and intraoperative findings were all analyzed.

Results: The incidence of labyrinthine fistula was 12.7 percent. During surgery the matrix over the fistula was removed in all but one case. A labyrinthine fistula occurred in larger cholesteatomas as demonstrated by the higher number of cases with more than two sites involved ( P < 0.001), facial nerve exposed ( P < 0.001), and stapes superstructure eroded ( P = 0.010). Postoperative change of bone conduction threshold and postoperative dead ears were not significantly different between fistula and nonfistula cases.

Conclusions: The preservation of the bone conduction threshold is a common finding in small fistulas and can be obtained also in “large” fistulas when appropriate surgical technique is used. In fistulas involving the promontory the matrix should be left in situ when the endosteum is involved.

Effectiveness of a mucolythic agent as a local adjuvant in revision lumbar spine surgery

Aim of this prospective randomized trial was to analyze the effectiveness of MESNA in chemical dissection of peridural fibrosis in patients who underwent revision lumbar spine surgery. Between January 2003 and October 2006, 30 patients who underwent revision lumbar spine surgery were enrolled in the study. Patients were randomly assigned to one of two groups: a study group (A) and a control group (B). Once peridural fibrosis was exposed, MESNA (Uromixetan MESNA, 50 mg/ml) was intraoperatively applied on the fibrous tissue (Group A) to ease tissue dissection and enter the canal. In patients of Group B, saline solution was used. Surgical time, preoperative and 1 week postoperative hemoglobin (Hb), length of hospitalization (days), and incidence of perioperative complications were evaluated. The blinded surgeon assigned the surgeries to one of four categories as none, minimal, moderate, and severe basing on intraoperative difficulty in dissecting the fibrous tissue and intraoperative bleeding. Statistical analysis used chi-square analysis to evaluate the difference in surgery difficulty and the incidence of intraoperative complications between the two groups. The analysis of surgical time and hemoglobin levels was performed using a one-sample Wilcoxon test and Mann-Whitney U test. Patients in whom MESNA was used intraoperatively (Group A) presented better intraoperative and perioperative parameters with respect to the control group. Average surgical time and decrease in Hb postoperatively were more in the saline group (B) respect to MESNA (A) (P = 0.004 and P = 0.001, respectively), while no difference in average hospital stay was reported between the two groups. Surgeon-blinded intraoperative report on surgical difficulty showed a significant difference between the two groups (P < 0.05). Postoperatively, no complications directly attributable to the use of MESNA were experienced. The incidence of dural tears and intraoperative bleeding from epidural veins were significantly less in Group A with respect to the control group. MESNA contributed significantly to reduce the operative complications, with a diminution of the surgical time and the grade of difficult for the surgeon, confirming its ability as chemical dissector also for epidural fibrosis in revision lumbar spine surgery.

Chemically assisted endoscopic mechanical submucosal dissection by using mesna

BACKGROUND

A class of thiol compounds, mesna (sodium-2-mercaptoethanesulfonate), has been used to facilitate tissue dissection in surgical fields.

OBJECTIVES

To evaluate the technical feasibility and efficacy of chemically assisted endoscopic mechanical submucosal dissection (CAEMSD) by using mesna.

DESIGN

An in vivo controlled blind trial by using porcine models.

SETTINGS

Nonsurvival study in an animal laboratory.

INTERVENTIONS

Six pigs were studied. Mucosal targets of about 2 cm (estimated) for treatment were created with a circle of cauterized spots along the greater curvature of the gastric body and the antrum. A mesna solution or the control hydroxypropyl methylcellulose solution was submucosally injected. The target mucosa was mechanically isolated with balloon dissection and removed by circumferential incision with a hook-knife inserted into the submucosal space. Necropsy and mucosal specimens from both groups were examined by histology.

RESULTS

En bloc resection of the target was achieved in all 8 attempts of the mesna group and in 7 of 8 attempts of the control group. Use of mesna significantly reduced tissue resistance to the initial balloon-catheter insertion into the submucosa and the technical difficulty of subsequent submucosal balloon dissection by using a subjective grading system (P < .05). There was no difference in histology between both groups.

CONCLUSIONS

CAEMSD is a unique methodology to facilitate mucosal resection.

Practical Use of MESNA in Atelectatic Ears and Adhesive Otitis Media

OBJECTIVE

MESNA is a synthetic sulfur compound that produces mucolysis by disrupting disulfide bonds. This study aimed to address indications and technique of MESNA application in otologic surgery, especially in retraction pockets and adhesive otitis media.

METHODS

MESNA application was performed in 42 ears of 39 patients. The diagnoses were retraction pockets fixed to incudostapedial joint, stapes or promontorium, and adhesive otitis media in 24 and 17 ears, respectively. Calculations were performed according to 24 ears of 23 patients with follow-up data.

RESULTS

One or more of the following surgical interventions were performed: MESNA application alone and ventilation tube insertion, reinforcement or mastoidectomy in addition to MESNA application. Sensorineural hearing loss was not encountered after MESNA application. The operation was successful in 79.2%. Overall revision surgery was needed in 20.8% of the ears. In 71.4% of the ears treated with MESNA alone, revision surgery was needed.

CONCLUSION

In the light of our experience, we advocate the use of MESNA in atelectatic ears, because it makes the operation easy and safe by allowing elevation of the tympanic membrane by its mechanical and chemical actions.

The effectiveness of sodium 2-mercaptoethane sulfonate (mesna) in reducing capsular formation around implants in a rabbit model

The development of capsular contracture is the most common complication associated with the insertion of breast implants. The authors studied the role of sodium 2-mercaptoethane sulfonate (mesna) in reduction of capsular formation in a rabbit model. Two 40-cc textured saline implants were placed dorsally into each of the 20 rabbits in the study. At the time of insertion of the implants, 10 ml of a 10% solution of mesna was instilled into one of the pockets and normal saline was instilled into the other. The implants were removed and a capsulectomy was performed at 5 months. The capsules were examined histologically for qualitative differences between the two groups. Quantitative analysis of the thickness of the capsule and the myofibroblast populations was also performed and compared between the two groups. The mean total thickness of the capsule around the implants was 496.8 microm in the mesna-treated group compared with 973.7 microm in the saline-treated group (p < 0.001). Likewise, the thickness of the myofibroblast layer was reduced in the mesna-treated group at 283.2 microm versus 555 microm in the saline-treated group (p < 0.0001). The capsules were also relatively less vascular in the mesna-treated group. Because of its ability to reduce the extent of capsular formation and to diminish development of myofibroblasts in the capsules, mesna would appear to be a useful adjunct in the prevention of capsular contracture formation.