Canal Patency Research Articles

A novel anchoring system for colonic stents: a pilot in vivo study in a porcine model

Colorectal stents have a proven role in colorectal cancer as palliative care or a bridge to surgery. However, their efficacy and anchoring to the tissue varies according to stent design with stent migration rates up to 50%. We present preliminary in vivo results of a new end-luminal anchoring system for stent fixation to the rectal canal. The aim was to assess the efficacy and safety of the stent using the anchoring system while subjecting the device to daily abdominal pressures related to daily activities in a porcine animal model. Ex vivo anatomical and physical studies were performed to improve the system's structure and safety. Four female pigs were followed for the acute and chronic (16weeks) period. Two animals were euthanized and underwent en-bloc pelvic visceral excision and histopathological examination. Device fixation time, animal behavior, device patency, anoscopic examination and histopathological features were assessed. Mean anchoring time was 13.83weeks (standard error±1.38weeks). One of the animals experienced early device expulsion with no complications. No obstruction was noted in any of the animals. Macroscopic examination revealed mild focal submucosal scarring in one animal and a normal examination in the other. Hematoxylin and eosin staining revealed mucosal ulceration and mixed inflammatory cell infiltrate, with no signs of granulomata, foreign body giant cell reaction or microabscess formation. A novel fixation device designed for long-term intrarectal implantation was well tolerated and maintained anal canal patency without migration. Larger studies are needed before its implementation in humans.

Glide Path in Endodontics

ABSTRACT Endodontic success depends primarily on good obturation. Obturation is a complex procedure that depends on many important steps. Overlooking any step may lead to failure of the endodontic treatment. Glide path is one of the most important steps during biomechanical preparation, which determines the canal patency until the apex and successful subsequent obturation. This article reviews some of the parameters regarding this very important step. How to cite this article Kumar A, Sarthaj S. Glide Path in Endodontics. Cons Dent Endod J 2017;2(2):48-51.

Deficit trasversale del mascellare superiore e problematiche relative all’orecchio medio

ObjectivesRestriction of the maxillary dental arch frequently results in decreased nasal canal patency with mouth breathing, and this situation may also be associated with conductive hearing loss. The aim of this paper is to review some of the literature on this condition and to advance several hypotheses regarding the changes observed in conductive hearing loss following orthodontic-orthopedic treatment. Materials and methodsA literature review was carried out to critically analyze the relationship between “rapid maxillary expansion” and “improvement in conductive hearing loss”. ResultsThe limited data in the literature on this specific topic suggest that hearing levels can be improved by correction of the palatal anatomy. ConclusionsThe positive effect on conductive hearing levels can be considered a possible additional benefit of rapid maxillary expansion, but this does not mean that rapid maxillary expansion should be proposed as a treatment for conductive hearing loss that is not associated with maxillary restriction.

Revision Aural Atresia Surgery

To determine the most common indications for revision congenital aural atresia (CAA) surgery and the postoperative healing and hearing outcomes of revision surgery. Retrospective case review. Tertiary care academic otologic practice. Patients undergoing revision surgery for CAA. Revision surgery for CAA. Indications for revision atresiaplasty, time to revision surgery, postoperative external auditory canal (EAC) patency, incidence of chronic drainage and/or infection, and postoperative speech reception thresholds (SRTs), and air-bone gaps. Indications for 75 ears (69 patients) undergoing 107 revision operations for CAA included 58% for EAC stenosis, 19% for chronic drainage and/or infection, and 20% for conductive hearing loss (CHL) alone. Fifty ears (67%) required a single revision. Twenty-five ears (33%) required more than 1 revision. With follow-up longer than 3 months (mean, 41 mo), 69% of ears revised for EAC stenosis achieved a patent canal (29% required >1 revision); 75% of ears revised for chronic drainage and/or infection (mean follow-up, 53 mo) realized a dry canal (22% required >1 revision). For all revision surgeries with adequate follow-up (n = 80), the mean postoperative short-term SRT of 24 dB HL was a significant improvement from the mean preoperative SRT of 39 dB HL (p < 0.01, paired t test). EAC stenosis is the most common indication for revision atresiaplasty. Despite the challenges of revision surgery, improvement in canal patency, epithelialization, and hearing utcomes can be achieved.

Sphincter-like motion following mechanical dilation of the internal inguinal ring during indirect inguinal hernia procedure

Even today, there is still great speculation as to the underlying pathogenesis of inguinal hernia. As a result, it could be extrapolated that the vast majority of repairs are based upon conjecture. Most current repairs are founded upon the principle of "closing the defect" in the anatomy, either by suturing closed under tension, covering with a mesh or obliterating the defect with a plug. Many variants of each method are refined to achieve better clinical outcomes. Yet few, if any, strive to understand a fundamental question: "What has gone wrong with the normal physiological and anatomical mechanisms that prevent abdominal structures protruding through the abdominal wall?" We consider, in the normal subject, the muscular structures that converge and wrap around the inguinal canal as a highly dynamic structure, which forms a reactive barrier to the augmentation of intra-abdominal pressures. In effect, the structures work together like a "striated sphincter complex." Through years of surgical experience, we have seen the formation of adhesions and fibrosis in these delicate and key structures, and hypothesised that they may impair its shuttering action, thus, creating a patency of this jammed inguinal ring leading to hernia. Based upon these observations, we have created a hernia repair variant that tries to "unblock" the muscles prior to repair, thus, hopefully restoring a degree of physiologic function. A retrospective study describes the results of 47 patients operated for indirect inguinal hernia with a standardised procedure consisting of meticulous adhesiolysis of the hernia area and mechanical dilation (divulsion) of the inguinal orifice in order to break stiff fibres within the muscle, allowing viable muscle fibres to contract freely once more. After dilation, a proprietary lamellar-shaped implant was delivered into the canal. Its form and function are designed to eliminate impingement of the cord structures and give a gentle outwards force to induce a reactive contraction of the sphincter-like muscle complex during healing. This gentle contraction offers the possibility to eliminate fixation of the implant. The removal of scar tissue, dilation and the introduction of the implant into the internal inguinal ring induced a forceful "gripping" contraction by the sphincter complex in all patients. Even without fixation, it became almost impossible to pull the implant out of the canal. After obliterating the orifice with the lamellar implant, it was clear that there was no dilative compression upon the cord structures. The results of this combined procedure, scar removal, dilation and implant delivery, led to thoughtful suggestions regarding the anatomy and the physiology of the inguinal canal. The procedural adhesiolysis during indirect inguinal hernia repair has always shown the well described concentric muscular arrangement formed by the internal oblique and transversus muscles. This circular-shaped muscular structure is often recognised as a static barrier that, due to weakness and/or together with other causes, fails in its role and allows indirect inguinal hernia protrusion. According to the results of our observations, we consider this concentric muscular complex as a dynamic formation: we will use the term "striated sphincter complex." Its steady tightening motion after divulsion and the insertion of a lamellar implant is always accompanied by a strong gripping action, which is not seen prior to divulsion. This indicates that it could correspond to a sphincter: the "inguinal sphincter." The impairment of this sphincter could be the cause of the inguinal canal's patency and the development of hernia.

酸化チタン液浴下におけるＮｄ：ＹＡＧレーザーの根管内照射が根管壁象牙質に及ぼす影響について

A fine flexible glass fiber made of quartz has been developed to transmit laser beams more effectively to a specific area. This may increase the potential usefulness of the Nd: YAG laser for root canal treatment. Recent investigations revealed that colloidal TiO2 irradiated by lasers generated laser photolysis and electron paramagnetic resonance (EPR). The aim of this study was to evaluate root canal preparation using Nd: YAG laser with TiO2 solution.Twenty-seven roots removed at 11mm from the apex were used. Root canal patency was confirmed using a No.10 K-file. Then, each sample was fixed to a movable stage, and the fiber tip was inserted near to the apex. The root canal walls were irradiated for 10 sec by Nd: YAG laser. The fiber tip was moved from the apical portion of the root canal towards the canal orifice at a speed of 1mm/sec. The root canal was filled with 5% TiO2 solution during lasing. As to laser irradiating parameters, the output energy was 120mJ, pulse frequency was 15, 30 and 60pps, and the repetition of lasing was 2, 4 and 8 times. Before lasing, the fiber was processed by Nd: YAG laser irradiation through itself in TiO2 solution for 30 sec. This procedure changed the laser irradiating pattern from straight to spherical. The lased samples were evaluated by contact microradiography, digital microscopy and scanning electron microscopy. The mean rates of increase of longitudinal cross sectional root canal space were 100.13±5.51% (15pps, 2 times), 94.42±14.37% (15pps, 4 times), 97.91±8.02% (15pps, 8 times), 100.16±20.88% (30pps, 2 times), 120.52±16.40% (30pps, 4 times), 103.55±10.66% (30pps, 8 times), 102.41±8.46% (60pps, 2 times), 101.01±24.54% (60pps, 4 times), and 96.13%±1625% (60pps, 8 times), respectively. No carbonization of the lased dentin surfaces was observed by digital microscopy and scanning electron microscopy when pulse repetition rate was less than 20pps. In conclusion, the lasing parameters of pulse energy 120mJ and repetition rate 30pps may be appropriate for Nd: YAG laser irradiation of root canals filled with TiO2 solution.

Surfer's Ear: External Auditory Exostoses are More Prevalent in Cold Water Surfers

The study goal was to demonstrate the prevalence and severity of external auditory exostoses (EAEs) in a population of surfers and to examine the relationship between these lesions and the length of time surfed as well as water temperature in which the swimmers surfed. It was hypothesized that subjects who predominantly surfed in colder waters had more frequent and more severe exostoses. Two hundred two avid surfers (91% male and 9% female, median age 17 years) were included in the study. EAEs were graded based on the extent of external auditory canal patency; grades of normal (100% patency), mild (66% to 99% patency), and moderate-severe (<66% patency) were assigned. Otoscopic findings were correlated with data collected via questionnaires that detailed surfing habits. There was a 38% overall prevalence of EAEs, with 69% of lesions graded as mild and 31% graded as moderate-severe. Professional surfers (odds ratio 3.8) and those subjects who surfed predominantly in colder waters (odds ratio 5.8) were found to be at a significantly increased risk for the development of EAEs. The number of years surfed was also found to be significant, increasing one's risk for developing an exostosis by 12% per year and for developing more severe lesions by 10% per year. Individuals who had moderate-severe EAEs were significantly more likely to be willing to surf in colder waters than were those who had mild EAEs (odds ratio 4.3). EAEs are more prevalent in cold water surfers, and additional years surfing increase one's risk not only for developing an EAE but also for developing more severe lesions.

Treatment of chronic otitis externa by KTP/532 laser.

The traditional meatoplasty operations performed for chronic otitis externa, which has entered the 'fibrotic' phase, are often unsatisfactory because the results in terms of canal patency, hearing gain and patient satisfaction are variable. Although the use of laser in chronic ear surgery is well recognized, it has not been previously reported as a meatoplasty technique. Ten KTP laser meatoplasty operations were performed on eight patients with chronic otitis externa. This pilot study shows the technique to be effective, fast and with a high patient satisfaction rate in the short-term (mean follow-up period 9.3 months). The average increase in hearing thresholds was 24 dB HL. Significant patient benefit was obtained in at least six out of eight patients using the Belfast rule of thumb. The technique has many advantages over the traditional meatoplasty operations but the long-term results require evaluation.

Endodontic retreatment: a rational approach to non-surgical root canal therapy of immature teeth.

The specificity of retreating immature teeth involves generally a broadly wide open apex and/or an inverted root canal conicity (apical opening wider than the root canal orifice), a periapical pathology leading often to a continuous canal exudation and thin and fragile dentinal walls. Nonsurgical endodontic retreatment of immature teeth consists at first in removing coronal and root canal iatrogenic obstructions in order to regain total canal patency. Apexification is then the treatment of choice, preceding a final gutta-percha obturation. The present article outlines a step-by-step rational approach to the root canal retreatment of immature teeth, pertaining to their biomechanical and pathological specificity.

Endodontic retreatment: A rational approach to root canal reinstrumentation

During nonsurgical endodontic retreatment, endodontic instruments are forced apically to remove the root canal filling material and regain canal patency. Undiscriminating burrowing down the canal in the apical direction may be fruitless and harmful. To avoid complications, the dentin overhanging the canal orifice must be removed and an unobstructed access established to the root filling material, so as to facilitate its removal. Reinstrumentation of the filled canal must take into consideration the nature of the filling material and the physical properties of endodontic instruments, as well as the dynamic aspects of canal preparation. This article discusses the mechanical considerations pertaining to root canal retreatment and outlines a step by step rationale approach to retreatment.

Comparison of rectal, axillary, and tympanic membrane temperatures in infants and young children

To evaluate the reliability of a tympanic membrane thermometer in detecting fever in young children presenting to the emergency department. Pediatric emergency department in an urban teaching hospital, DESIGN/MEASUREMENT/PARTICIPANTS: Temperature measurements were obtained sequentially at three body sites in children less than 3 years old presenting to the pediatric ED. Axillary and rectal temperatures were obtained with an electronic thermistor probe (Diatek 500), and tympanic membrane temperatures were obtained with a noncontact, infrared sensing device (First TEMP). Patients were stratified by age, ear canal patency, presence of otitis media, and rectal temperature. Of 224 patients enrolled, 87 (39%) were febrile. Overall correlation of axillary and tympanic membrane measurements to rectal for all strata was .75 (P = .001) and .81 (P = .001), respectively. Sensitivity in detecting fever for axillary and tympanic membrane sites was .48 and .55, respectively. Otitis media and ear patency did not influence correlation of tympanic membrane measurements. Low tympanic membrane temperature sensitivity may be a result of probe configuration. Tympanic membrane and axillary temperatures should be viewed with caution in children less than 3 years old as neither can detect fever reliably.

Neurologic return versus cross-sectional canal area in incomplete thoracolumbar spinal cord injuries.

Twenty-four patients with incomplete spinal cord injuries secondary to burst fractures of the thoracolumbar spine were reviewed an average of 26 months after their injury. No patient had had a specific attempt to decompress neural elements but the majority had posterior instrumentation and fusion for spine realignment and stabilization. The amount of neurologic recovery in each patient was compared to the final area of the spinal canal as determined by CT scan. It was concluded that there was no correlation between neurologic improvement and the amount of spinal canal encroachment. In addition, posterior instrumentation to realign the spine will usually restore canal patency to greater than 50% of normal.

The effect of four preparation techniques on the amount of apically extruded debris

The amounts of root canal material extruded from extracted teeth using four instrumentation techniques were compared. Eighty extracted human mandibular premolars with single canals and root curvatures of 9 to 28 degrees were divided into four groups: 1, conventional filing technique; 2, cervical flaring technique; 3, ultrasonic technique; and 4, sonic technique. The teeth were opened for endodontic access and a #10 file passed 1 mm beyond the apex to ensure canal patency. All teeth were prepared 1-mm short of the apical foramen. Debris extruded in each case was collected and weighed after it was desiccated. The mean weights of extruded material for the groups were compared by analysis of variance. There was a statistically significant difference in debris extrusion between the conventional filing technique and the sonic technique. The groups ranked from lowest to highest in debris extrusion were as follows: 1, sonic technique; 2, cervical flaring technique; 3, ultrasonic technique; and 4, conventional technique.

Reconstructive teat surgery for complete teat canal obstruction

A new surgical technique to reestablish teat canal patency in obstructed teats is described. The technique entails opening the teat canal and inserting a prosthetic tube to reestablish milk flow.