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OBJECTIVES To report the outcomes of antibiotic cement coated interlocking nail (ACCIN) removal, detail a removal technique that mitigates debonding of coating, and describe how to address occurrences intraoperatively. DESIGN Retrospective case series. SETTING Sinai Hospital of Baltimore, Maryland. PATIENTS Twenty-eight patients who underwent ACCIN removal between January 2014 and August 2019. INTERVENTION Removal of ACCINs that were coated using the Silicone tubing method. MAIN OUTCOME MEASUREMENTS Successful removal of the nail with intact antibiotic coating. RESULTS A total of 42 ACCIN removals were included in this study. Successful ACCIN removal was achieved in 37 cases (88.1%), with debonding in only 5 cases (11.9%). Eight nails (19%) required 1 additional removal procedure and 3 nails (7.1 %) required 2 additional removal procedures. The main reasons for the additional procedures were nonunion and persistent infection. CONCLUSIONS ACCIN insertion and removal can be challenging. Proper technique of coating and insertion can facilitate later removal. Removal of knee-long fusion rods can be more challenging. LEVEL OF EVIDENCE Level IV.

Aim The aim of this study was to determine the feasibility and effects of temporary bilateral uterine artery occlusion with silicone tubing on blood loss during vacuum aspiration of cesarean scar pregnancies (CSP). Material and Methods Six patients with CSP underwent removal of gestational masses via vacuum aspiration. At the beginning of the procedure, all patients underwent laparoscopic temporary bilateral uterine artery occlusion with tubing. The main measurements were the operating time, operative blood loss, Doppler examination of the uterine arteries, and complications of procedure. Results The median operation time was 99 min, the median time needed to put the tubing in place (the time from the opening of the retroperitoneum to positioning of the tubing) was 45.5 min and the median time of bilateral uterine artery occlusion with tubing was 32.5 min. The median blood loss was 97.5 mL, and none of the patients required blood transfusion. Doppler examination showed no difference in the pre- and postoperative resistance or pulsatility indices of the uterine vessels. There were no conspicuous complications. The serum s-human chorionic gonadotrophin level decreased to normal within 14–27 days after the operation. Conclusion Laparoscopic temporary bilateral uterine artery occlusion with silicone tubing is an effective, minimally invasive procedure for reducing blood loss during vacuum aspiration in patients with CSP.

Objective To evaluate the safety of a novel ureteral occlusion device and compare its performance with that of other devices and guidewires. Methods The XenX (Xenolith Medical) was tested in an ex vivo porcine model to determine the percentage of denuded urothelium because of manipulation within the ureter, the capacity to prevent stone migration during laser lithotripsy, stent compatibility, and the ability to be used for stent placement. Comparative evaluations of the insertion forces and maneuverability were conducted in an in vitro ureter model with the XenX, Stone Cone (Boston Scientific), NTrap (Cook Urological), HiWire (Cook Urological), Roadrunner (Cook Urological), and Sensor (Boston Scientific). Stone migration efficacy was measured using a controlled distribution of stones in 4- and 10-mm silicone tubing with the XenX, NTrap, and Stone Cone. Results The XenX was safely manipulated within the ureter, prevented significant particle migration during laser lithotripsy, and effectively placed stents. The NTrap required the greatest force when attempting to navigate past a stone ( P = .0003), followed by the Stone Cone ( P = .009), with little difference among the other devices ( P > .72). No differences were found for the passing forces ( P = .061), interval to pass ( P = .30), or number of attempts to pass the stone ( P = .68). The XenX prevented stone migration the most, with more notable differences in the 10- than in the 4-mm tubing. Conclusion Ex vivo evaluations hold promise for the XenX to be safely and effectively used during ureteroscopic procedures. Clinical evaluations are warranted to confirm the safety and performance of the XenX relative to the other ureteral occlusion devices.

Widely dehisced abdominal wounds present as challenging surgical cases often incurring multiple complications such as bowel desiccation, perforation, and enterocutaneous fistula [1], equating a mortality of 25% [2]. With the extensive usage of topical negative pressure dressings, these complications have reduced. However these abdomens are now presenting as open wounds with incarcerated edges, necessitating skin grafting on bowel. We present an effective approach to the closure of open abdomens using a combination of topical negative pressure and elastic sutures improvised from silicone tubing. The elastic sutures stretch the skin and prevent wound edges from bedding down prematurely, thereby allowing primary closure.

Purpose: To assess the effectiveness and outcomes of canalicular intubation with the use of a round-tipped, eyed pigtail probe. Methods: Retrospective interventional case series of 228 patients requiring intubation of the canalicular system. Patients were treated surgically with attempted repair of the canalicular system with the round-tipped, eyed pigtail probe. The main outcome measures were successful intubation of the lacrimal system, symptoms of tearing, clinical functional evaluation of lacrimal system, complications, and need for further lacrimal surgery. Results: Of 228 patients, 222 (97.4%) had their canalicular systems successfully intubated with silicone tubing using the round-tipped, eyed pigtail probe. Follow-up was obtained in 191 (86%) of the 222 patients. One-hundred sixty of 191 (83.8%) patients were irrigated and found to be anatomically patent (of the remainder, one was blocked whereas 30 were too young to be irrigated). One hundred fifty-two of the 191 (79.6%) patients had no tearing by history. Thirty-two (16.7%) had occasional tearing on some days that was not bothersome. Seven (3.7%) had intermittent or persistent tearing on a daily basis. Sixty-seven of the 191 (35%) had their lacrimal system more extensively assessed using the dye disappearance test, Jones I test, Jones II test, and canalicular probing. Anatomic patency in this subgroup was demonstrated in 66 of 67 (98.5%) of patients. The dye disappearance test, however, revealed slight asymmetry in 24 of 53 patients (45%) with canalicular lacerations yet only 14 of these 24 (58%) had any symptoms of tearing, indicating some discrepancy between subjective and objective assessment of tearing postcanalicular repair. Fifty-three of the repaired trauma patients underwent probing of the involved and uninvolved canalicular systems. In no patient was a stricture or blockage involving the uninvolved canaliculus identified. Additional lacrimal surgery (dacryocystorhinostomy) was performed on 2 of 191 (1%) patients with greater than 3 months follow-up. Conclusion: The round-tipped, eyed pigtail probe can help safely and effectively identify and repair canalicular lacerations. Symptomatic tearing was infrequent; the lacrimal systems showed complete anatomic patency in the majority of patients tested, and need for further lacrimal surgery was rare following pigtail probe intubation.

Background Endoscopic dacryocystorhinostomy (EN-DCR) is an effective procedure when treating saccal and postsaccal obstructions of the nasolacrimal pathway. The benefit of silicone tubing after DCR is still controversial. We conducted a prospective, randomized study to evaluate the necessity of bicanalicular silicone tubes after primary EN-DCR. Methods Forty-six consecutive primary EN-DCR procedures were performed in 42 patients during 2004-2007. The patients were randomized into two study groups according to whether silicone tubing was used or not. Results The overall success rate after primary EN-DCR was 89%: with silicone tubes it was 78%, and without silicone tubes it was 100%. The difference between these two groups was statistically significant (p < 0.049). The follow-up period was 6 months and included three follow-up visits: 1 week, 2 months, and 6 months postoperatively. If inserted, the silicone tubes were removed at the 2-month visit. Conclusion The results of our prospective, randomized study showed that the use of silicone tubes after primary EN-DCR is not necessary.

Purpose: To evaluate whether silicone tube insertion is always necessary in external dacryocystorhinostomy (DCR). Methods: During external DCR for primary nasolacrimal duct obstruction carried out between January 2001 and October 2004, silicone intubation was not performed selectively if the lacrimal sac was large and the nasal cavity was not severely narrowed. Results: Of a total of 166 DCR cases in 153 patients, no silicone tube was placed in 74 eyes of 69 patients (44.6%). Anatomic patency of rhinostomy was achieved in all non-intubation group eyes. However, four (6.7%) of these 69 eyes showed persistent epiphora even with anatomic patency. Conclusions: Silicone tubing can be avoided in about 50% of cases of external DCR without detrimentally affecting the success rate. Cases in which intubation was avoided had a large lacrimal sac and a wide nasal cavity.

Background. Shunt infections are one of the major causes of mortality and morbidity of patients with hydrocephalus. The aim of this research is to compare the bacterial colonization characteristics of a regular silicone elastomer shunt material coated with polyvinylpyrrolidone and dimethylpolysiloxane (silicone). Method. Regular coated shunt materials were compared by in-vivo and in-vitro methods. In the in-vitro experiment, silicone and coated material immersed and not immersed in vancomycin solution was treated with a certain concentration of Staphylococcus epidermidis. In the in-vivo study, silicone and coated material specimens were treated with Staphylococcus epidermidis and they were stereotactically placed in the lateral ventricles of the rats. One week after the inoculation, shunt pieces were removed and the colonies were counted by using a scanning electron microscope. Findings. There was a statistically significant difference of colonization in the in-vitro groups in coated material vs. silicone, coated material vs. vancomycin treated silicone, vancomycin treated coated material vs. silicone, vancomycin treated coated material vs. vancomycin treated silicone. There was no statistically significant difference for colonization in in-vitro groups of coated material and vancomycin treated coated material. With in-vivo experiments we can say that, coated material catheters are superior than the silicone catheters in respect to colonization but after the bacterial colonization has occurred, the amount of colonization did not differ. Interpretation. Coated material catheters are superior to silicone catheters and they prevent bacterial colonization in some respect.

Tissue adhesion to bioactive glass-coated silicone tubing in a rat model of peritoneal dialysis catheters and catheter tunnels.BackgroundSilicone peritoneal dialysis catheters do not develop tissue ingrowth, lack a mechanical barrier to periluminal bacterial migration and need cuffs for anchorage. We hypothesized that a bioactive glass coating composed of silicon, calcium, sodium and phosphorous oxides would cause a beneficial tissue reaction causing catheter adhesion, and tested this in a rat model.MethodsA hexane solvent-based method of coating silicone tubes with Bioglass® powder was used, which maintained flexibility, and then the ultrastructure was confirmed with scanning electron microscopy (EM). Segments 2.5 cm were implanted subcutaneously in 8 Sprague-Dawley rats, with uncoated tubes as a contralateral control, and histology was done at 2, 4 and 6 weeks, including special stains and EM.ResultsThe uncoated segments grossly had no adherence to surrounding tissue, and were physically separate from a thin fibrous capsule of approximately 50 μ width. Trichrome stains demonstrated the capsule was rich in collagen. There was minimal adjacent tissue reaction. In contrast, the coated tubes were palpably fixed to the soft tissues, and sections demonstrated an adjacent prominent layer of macrophages and multinucleated giant cells. Small numbers of lymphocytes were noted. This cellular reaction increased over the 6-week implant duration, and was also associated with neovascularization of the tissue adjacent to the segments (33 vessels in coated vs. 20 in controls per ×200 field, P < 0.0001). Many refractile silicone particles and prominent multinucleated giant cells were present, with small numbers of lymphocytes and macrophages. Stains showed scattered discontinuous calcific deposits. These findings are consistent with reports that the Bioglass® silicon oxide leads to the formation of a layer of hydroxyapatite, which binds to collagen and induces a tissue cellular reaction.ConclusionsIn summary, bioactive glass coatings can improve the tissue retention of silicone tubing by promoting adhesion by collagen and cell proliferation, and are promising for future studies of peritoneal dialysis catheters.

Background Endoscopic dacryocystorhinostomy (DCR) is an effective surgical procedure to treat saccal and postsaccal stenosis or nasolacrimal duct obstruction. The use of silicone tube after endoscopic DCR is still controversial. A prospective randomized study was conducted to compare the success rate between the use of silicone stent and no use of silicone stent in endoscopic DCR. Methods A prospective randomized study was conducted at Aseer Central Hospital and Abha Private Hospital, Abha, Kingdom of Saudi Arabia, on all patients undergoing endoscopic DCR between July 1, 2006 and 30 June 30, 2010. Patients were allocated randomly for endoscopic DCR with or without stent. The data collection included age, sex, diagnosis, method, and duration of surgery. Patients were followed up postoperatively at 1 week, 1 month, and then every 3 months for 1 year. Results During the period of the study a total of 173 cases of postsaccal stenosis underwent endoscopic DCR (67 male and 106 female subjects). The mean age was 51.8 years (range, 18–72 years). A stent was used in 92 patients (53.2%) and not used in 81 patients (46.8%). With silicone tubing the success rate was 96%, and without silicone tubing it was 91%, an overall success rate of 94%. The odds ratio of failure without a silicone tube was 3.25 but confidence interval was from 0.84 to 12.60 and the difference between these two groups was statistically not significant (p = 0.117). Conclusion In this study, there was no statistically significant advantage of using endoscopic DCR with stent over the endoscopic DCR without stent.

Object The authors conducted a study to develop a safe and effective intracranial venous sinus reconstruction for extensive clinical use. Methods After resecting the superior sagittal sinus (SSS), it was reconstructed in eight dogs by performing either a tube-insertion technique or end-to-end anastomosis procedure, in both of which a thin-walled silicone tube was used for repair. The patency of the SSS reconstruction was observed on digital subtraction angiography and transcranial Doppler ultrasonography, preoperatively and at 1, 2, 4, and 8 weeks postoperatively. Histological and ultrastructural changes were observed using light and electron microscopy. In five dogs the reconstructed SSS was patent, in one it was narrowed, in one it was completely occluded at the proximal site of the anastomosis, and one dog escaped from the laboratory 1 week postoperatively. The authors found no evidence of any additional neurological deficits, signs of toxicity, or side effects. Histological and ultrastructural studies generally showed vascular endothelial proliferation. No thrombosis occurred in the inner surface, at the site of anastomosis, or in the lumen of silicone tube nor in the sagittal sinus at up to 8 weeks postoperatively. Conclusions The use of a thin-walled silicone tube as an artificial substitute for intracranial dural venous sinus reconstruction seems to be a valuable technique. The silicone tubes were found to have good biological compatibility, nonthrombogenic effects, and a high patency rate. The method was found to be simple and effective as well as practicable in the clinic for the short term (8 weeks). The authors emphasize that Phase I clinical trials involving silicone tube–assisted SSS reconstruction require further research.

In this chapter, we describe the specific complications relating to the neurosurgeon’s choice of any given shunt system used in different clinical conditions and age groups. Most neurosurgeons have a particular favourite CSF shunt system and burr-hole site that they use for the majority of their patients, but in hydrocephalus management there is no perfect shunt for all occasions and each type of shunt system has its own peculiar strengths and weaknesses. Certain design features such as valve profile, size of valve components, presence of barium, distal slits or springs in the silicone tubing, number of connection points within the system and impregnation with antibiotics will all influence the risk of shunt complications, as well as the more obvious features such as pressure and flow characteristics.

Background Endoscopic dacryocystorhinostomy (EN-DCR) is increasing in popularity as a treatment of nasolacrimal obstructions because it has proven to be an effective and safe procedure. In this study the success of EN-DCR combined with or without bicanalicular silicone stents was evaluated in patients with nasolacrimal obstructions. Methods Forty-two consecutive EN-DCR procedures were performed in 36 patients during 2000–2004. The surgery was primary in 23 cases and revision in 19 cases. Bicanalicular silicone stents were inserted in 18 cases and in 24 cases stenting was avoided. Results The overall success rate after EN-DCR was 81%. The success rate of EN-DCR was 89% with silicone tubing and 75% without silicone tubing. The mean duration of postoperative follow-up was 4 months. Conclusion In our retrospective study no significant statistical differences were seen between the patients with stenting compared with patients without stenting. However, prospective, randomized studies are clearly needed to answer the question of whether the use of stents is advisable.

Aim of the present study was to determine the efficacy of intranasal endoscopic silicone intubation to treat congenital nasolacrimal duct obstruction in children who failed conventional lacrimal system probing. Silicone intubation with intranasal endoscopic visualization was performed in 18 eyes of 16 patients with an age range of 18–48 months (mean, 25 months) to treat congenital nasolacrimal duct obstruction. Out of 16 patients, ten had already undergone previous probings with failure, the other six were primary intubation cases without any previous probings. The tubes were left in place an average of 6 months. Follow-up ranged from 4 months to 2 years (mean, 12 months) following removal of the silicone tubing. Intranasal endoscopic silicone intubation is effective in the treatment of congenital nasolacrimal duct obstruction as a primary procedure in children over 18 months of age and, it is also recommended as the next step in the management of epiphora which fails to resolve after probing.

The authors report 20 cases of endonasal dacryocystorhinostomy using standard otolaryngological surgical instruments. The technique used was, briefly: An osteomucous window was opened just anterior to the medial turbinate, starting superiorly to the inferior turbinate. The lacrimal sac was visualized and its medial wall excised. The lacrimal apparatus was canalized using silicone tubing.

The EMS Swiss LithoBreaker is a new, portable, electrokinetic lithotripter. We compared its tip velocity and displacement characteristics with a handheld, pneumatic lithotripter LMA StoneBreaker.™ We also evaluated fragmentation efficiency using in vitro models of percutaneous and ureteroscopic stone fragmentation.Displacement and velocity profiles were measured for 1-mm and 2-mm probes using a laser beam aimed at a photo detector. For the percutaneous model, 2-mm probes fragmented 10-mm spherical BegoStone phantoms until the fragments passed through a 4-mm mesh sieve. The ureteroscopic model used 1-mm probes and compared the pneumatic and electrokinetic devices to a 200-μm holmium laser fiber. Cylindrical (4-mm diameter, 4-mm length) BegoStone phantoms were placed into silicone tubing to simulate the ureter; fragmented stones passed through a narrowing in the tubing.For both 1-mm and 2-mm probes, the electrokinetic device had significantly higher tip displacement and slower tip velocity, P0.01. In the percutaneous model, the electrokinetic device needed an average of 484 impulses over 430 seconds to fragment one BegoStone, while the pneumatic device needed 29 impulses over 122 seconds to fragment one stone. Both clearance times and number of impulses needed for percutaneous stone clearance were significantly different at P0.01. Ureteroscopically, the mean clearance time was 97 seconds for the electrokinetic lithotripter, 145 seconds for the pneumatic lithotripter, and 304 seconds for the laser. Comparing the pneumatic device with the electrokinetic device ureteroscopically, there was no significant difference in clearance time, P=0.55. Both the pneumatic and electrokinetic lithotripters, however, demonstrated decreased clearance times compared with the laser, P=0.027.The portable electrokinetic lithotripter may be better suited for ureteroscopy instead of percutaneous nephrolithotomy. It appears to be comparable to the portable pneumatic device in the ureter. Further clinical studies are needed to confirm these findings in vivo.

The mean forces required to dislodge two types of endoscopic ligation clips from both porcine cystic ducts and silicone tubing were quantitated. The two types of endoscopic clips were EndoClip II and Ligaclip ERCA. Following application of the clips, the force required to dislodge the clips in both a perpendicular direction and a longitudinal direction was determined. The mean levels of force required to dislodge the EndoClip II clips in both directions were significantly (p ≤ 0.01) greater than those required to dislodge the Ligaclip ERCA clips.

The author reports a new bicanalicular intubation method using a Nunchaku-style silicone tubing (n-st) which consists of three pieces. One piece is the thinner central segment, and the other two are thicker bilateral segments. In the new method, there is no difficult procedure of retrieving the tip of a metal probe from the nasal cavity. The n-st requires no suture to secure it in position. The author believes the n-st makes bicanalicular intubation easier and leads to more frequent use, and results in a reduced number of major surgical interventions.

Purpose To report a series of lacrimal complications associated with a specific type of lacrimal plug (Herrick Lacrimal Plug; Lacrimedics Incorporated, Rialto, CA.) Design Retrospective, noncomparative case series and survey. Methods Members of the American Society of Ophthalmic Plastic and Reconstructive Surgery were asked to submit personally treated cases of patients referred for treatment of complications after placement of a Herrick Lacrimal Plug. Main outcome measures Failure of the device to be removed by simple lacrimal irrigation. Results The clinical courses of 41 patients were analyzed. Patients ranged in age from 19 to 81 years, and all had symptomatic epiphora related to the presence of the lacrimal plug. Several interventions were used to treat lacrimal obstruction. Nasolacrimal duct probing with irrigation was used in 15 lacrimal systems, whereas six systems were probed and subsequently stented with silicone tubing. Eyelid margin cutdown was used in eight cases. Balloon dacryoplasty was performed in three systems, dacryocystorhinostomy in 18 instances, and conjunctivodacryocystorhinostomy in two patients. Conclusions The Herrick lacrimal occlusion device sometimes cannot be removed by simple irrigation and is capable of inducing permanent, irreversible, symptomatic lacrimal drainage system obstruction.

Purpose: To evaluate the success rate of dacryocystorhinostomy (DCR) for epiphora in patients with a clinically patent lacrimal drainage system. Methods: A series of 51 patients, 12 men and 39 women, who underwent DCR surgery for epiphora with a clinically patent lacrimal drainage system in the background of normal eyelid examination, were evaluated. All patients underwent fluorescein dye disappearance testing and Jones 1 and 2 testing with dacryocystograms in borderline cases. A standard DCR was performed with bicanalicular silicone tubing inserted in all cases. The average time for the removal of the silicone tubes was 9.6 weeks. Results: In 48 cases (94%) there was improvement in symptoms with minimal or no significant epiphora postoperatively. Conclusions: Epiphora with a patent lacrimal drainage system obstruction can be successfully treated by DCR based on fluorescein dye disappearance tests and Jones 1 and 2 tests, with dacryocystography in borderline cases.

Silicone tubes are widely used in lacrimal system surgery. A common complication associated with the use of silicone tubes is lateral migration or displacement of the tubes. In some cases, the distal part of the silicone tube passes through the rhinostomy area, where it may become embedded in the lacrimal sac. The silicone tubes could not be seen in the nose endoscopically. The distal part of the silicon tube could not be seen in the rhinostomy area, so it was removed using a new method.

We describe a procedure to secure a jugular vein catheter system at the dorsal nape of the neck in the hamster. An 8-cm piece of silicone tubing is connected with a 2.6 cm L-shaped metal tubing which is embedded in prosthetic material. The prosthetic material is placed underneath the neck skin of the hamster and keeps the metal end of the catheter system in a sturdy, upright position.

Hypothesis Transdermal sustained-delivery oxygen therapy improves wound healing. Design Experimental study using a well-established rabbit ear model for acute wound healing. Setting Wound-healing research laboratory in a university center. Methods Four full-thickness 7-mm punch wounds were created on each ear of young, female New Zealand white rabbits. Treated ears received transdermal sustained delivery of oxygen via silicone tubing tunneled subcutaneously to a pocket under a semiocclusive dressing. Oxygen production (100% oxygen at 3 mL/h continuously) relied on a small, self-contained device connected to the silicone tubing and secured to the rabbit’s back for the duration of the experiment using a body harness. Ears were harvested at each of 2 time points: day 5 and day 8. Results Histologic analysis of the wounds showed significantly greater healing at both day 5 and day 8 in response to oxygen therapy. Most significantly, epithelial wound coverage was almost doubled in treated ear wounds when compared with controls. Conclusion Our results suggest that epithelial wound healing is improved by transdermal sustained-delivery treatment with 100% oxygen.

Most currently used disinfectants for dialysis machines have a good bactericidal efficacy on biofilms but leave dead cells on the surface. This contributes to the regrowth of biofilm and the release of pyrogens. A new anti-biofilm procedure consisting of sequential treatment combining enzymes and detergents is able to detach adherent cells. The efficacy of this procedure was assessed both in vitro and in reality. For in vitro studies, a biofilm model was set up. Studies were also performed in reality in a clinically used dialysis machine. Biofilm removal was first monitored by image analysis. Then, the biomass was detached by scraping and quantified by plate counts and endotoxin level measurement. Treated samples were compared to untreated control samples. The procedure led to the complete detachment of the biomass, both in vitro and in the reality situation. The aim of thisprocedure is to replace or complete the usual disinfection methods for medical devices.

A rigid-type of polyethylene T-cannula was fitted into the anterior ileum of six horses in order to improve the cannulation techniques. A piece of polyethylene net was fastened onto the intestinal wall around the cannula to prevent dislodgment of the cannula by promoting a secure adhesion between the ileum and the abdominal wall. The cannula barrel sheathed with silicone tubing was exteriorized through a stab incision at the lateral ventral wall on the transverse line of the second lumber vertebra, and a flange was screwed onto the barrel. The feeding regime gradually increased concentrate without roughage prevented any colic signs. The use of these techniques succeeded in the ileal cannulation with no leakage of digesta.

The authors describe the usefulness of split silicone tubing to protect the cranial nerves and arteries during microneurosurgery. The inner diameter of the tube varied from 1.0 to 3.3 mm with a thickness of 0.125 mm. Application of the tube protects the nerves and arteries from mechanical trauma, electrical injury, and dryness.

Silicone tubing of the lacrimal pathway is used after lacrimal pathway injuries or canalicular stenosis. This procedure is often complicated by the so-called accordeon phenomenon. Far the last 3 years we have used a new system for lacrimal intubation: the Ritleng intubation set. It consists of a silcone tube which is connected to a polypropylene tube and a specially designed stainless probe for lacrimal insertion. Due to the smooth connection of the polypropylene tube and the silicone tube intubation can be performed easily and without the so-called accordeon phenomenon. In case of congenital or acquired lacrimal stenosis probing and silicone intubation can be performed in one step. We used this set in 19 lacrimal lacerations of the lacrimal pathway and in 7 cases of congenital and 12 cases of acquired lacrimal stenosis. With this specially designed lacrimal intubation set lacerated canaliculi can be quickly reapproximated. It allows probing of the lacrimal system and intubation in one procedure. In this report the technique and indications will be described and discussed.

A silicone tube segment was used for repairing the median and ulnar nerves in the forearm. This study includes 26 patients (20 male and six female), with a mean age of 23 years (range, 18-26). Injuries were caused by saw, knife and glass accidents, the latter being most frequent. The mean interval between the injury and repair was 101 days. Fourteen patients had median nerve injuries, eight had ulnar nerve injuries and four had both median and ulnar nerve injuries. The technique was effective in the repair of peripheral nerve injuries with gaps of up to 3 cm, with better results in the ulnar nerves than in the median nerves.

Objective: The aim of this study is to present our endoscopic DCR operation method without the use of silicone tubing and our results on the patients suffering from chronic epiphora with postsaccal stenosis. Methods: Endoscopic dacryocystorhinostomy operations were performed to 21 sides of 18 patients who had chronic epiphora. No silicone tubing was used in any of the cases. In the postoperative healing period, the rhinostomy opening was maintained with frequent removal of nasal debris and using eyedrops. The patients were evaluated by fluoresceine test and endoscopic controls. Results: Symptomatic improvement was achieved in 19 out of 21 sides of the patients (90.5%) and the results were confirmed by the fluoresceine test under endoscopic control. Conclusion: Our results of 21 sides of 18 cases underwent primary DCR without stents are as successful as those reported in the literature and the technique seems to be promising.

Purpose: To report a method of identifying the lower end of the nasolacrimal duct when more usual methods have failed. Methods: A vitreoretinal fibre-optic light pipe was used to identify the lower end of the nasolacrimal duct in a child with unusual congenital nasolacrimal duct obstruction. Results: This intraluminal light source enabled easy cut down onto the ‘blind’ end of the lacrimal drainage apparatus and subsequent intubation with silicone tubing to overcome the obstruction. Conclusion: This technique may prove useful in the rare cases in which it is not possible to identify the lower end of the nasolacrimal duct with a probe and nasal endoscope alone.

Twenty-eight patients (34 eyes) with congenital nasolacrimal duct obstruction underwent silicone intubation with the Ritleng lacrimal intubation system. The technique involves introduction of a Prolene (Ethicon Inc, Somerville, NJ) monofilament guide thread, securely fastened to the silicone tubing, into a tubular metal probe that opens into the inferior meatus. The outcome was evaluated in terms of ease of intubation and objective success rate. Thirty-two (94%) of the 34 lacrimal systems were successfully intubated with the Ritleng system. Difficulty passing the Prolene thread through the probe and out the tip, necessitating conversion to a Crawford intubation system, was encountered in only 2 eyes (6%). The Prolene spontaneously emerged from the nose in 24 (75%) of 32 eyes, making retrieval simple and uncomplicated. The success rate for relieving signs and symptoms of obstruction was 97% (31/32) for the eyes with the Ritleng system and 100% (2/2) for the eyes with the Crawford system. Bicanalicular silicone intubation with the Ritleng intubation system is an easy and effective technique for treatment of congenital nasolacrimal duct obstruction.

Migration of particulate matter from plastic tubing and solid plastic implants has been documented in a number of studies, including some with the use of cardiac bypass, haemodialysis, and pump-assisted intravenous infusions. In order to ascertain whether silicone embolisation occurs when children have an Ivac 560 pump-assisted IV infusion, we passed 180 ml of pumped fluid through a microfilter and compared the scanning electron micrographs of those filters with unused filters and with others through which a similar volume had been passed without using the pump. The particles on the filters were analysed for their elemental content using energy-dispersive X-ray analysis. In addition, the appearance of the silicone tubing used in the pump over 3 and 72 h was assessed and compared to that of flow-only and unused tubing. More particles were found on the microfilter when fluid had been delivered via the pump than on those through which non-pumped fluid had passed or that were unused. Elemental silicon-containing particles were only found on the filter when a pump had been attached to the IV line. The flow-only and unused tubing were found to have adherent particles on the inner surface that were not seen once the tubing had been used for 3 h in the Ivac 560 pump. Also, after 72 h use, the silicone tubing had a deformed inner layer. The clinical significance of these findings is yet to be determined, but it does appear that silicone embolisation occurs during pump-assisted infusions in children.

We have evaluated in vitro, the security of laparoscopically applied clips, through two commercially available clip appliers: the Endo Clip II (US Surgical) and the Ligaclip (Ethicon). The clip performance was tested with respect to dislodgment and leakage. Dislodgment was attempted both transversely and at 45 degrees with respect to the main axis of the tubular structures tested. The mean maximum force (N = 24) necessary to dislodge a clip applied to silicone tubing (2.1, 2.4, 3.2 mm o.d.) and porcine vascular tissue was measured. The maximum force needed to transversely dislodge a clip applied to silicone tubing, ranged from 262 +/- 9 g (2.1 mm) to 315 +/- 11 g (3.2 mm) for the Endo Clip II applier, while the values for the Ligaclip were 220 +/- 28 g (2.1 mm) and 273 +/- 11 g (3.2 mm), respectively. To achieve dislodgment at 45 degrees pull, corresponding forces of 294 +/- 8 g (2.1 mm) and 369 +/- 14 g (3.2 mm) for the Endo Clip II, and 254 +/- 14 g (2.1 mm) and 297 +/- 13 g (3.2 mm) for the Ligaclip (N = 24) were required. Transverse dislodgment forces, for clips applied to tissue, were 556 +/- 146 g for the Endo Clip II and 356 +/- 170 for the Ligaclip (N = 6). Leakage tests were also performed under pulsatile blood circulation at mean pressure of approximately 800 mm Hg. No tested clips applied to either silicone tubing or tissue allowed for any blood leakage. The dislodgment test showed that the Endo Clip II exhibits superior performance compared to the Ligaclip, based on the fact that it requires more force for transverse and semiaxial dislodgment. In the leakage test, both clip appliers performed equivalently.

A preliminary series of endonasal dacryocystorhinostomy was carried out on 12 patients with nasolacrimal obstruction using a recently developed combined CO2-Nd: YAG laser that was guided by a fiberoptic light pipe inserted into the lacrimal sac through lacrimal canaliculi. The lacrimal passages were stented using silicone tubing that was kept in place for 6 months postoperatively. At an average follow-up time of 14.3 months the success rate was 83%. The advantages of the operation include a relatively short operation time, quick rehabilitation, absence of a skin wound, good hemostasis, and preservation of canthal anatomy.

A study was conducted to modify the routinely used ovum pick up (OPU) devices to permit use of disposable needles and to simplify the technique and to make it more economical and practical to use. Long nondisposable needles are commonly used in transvaginal OPU despite several disadvantages. A new OPU device was developed using 19-g disposable needles to eliminate these disadvantages and to make the technique more successful. The disposable needle was connected to silicone tubing by means of a stainless steel connector. The system was inserted into a stainless steel tube, creating a rigid structure within which to move the needle back and forth. A blunt needle can be changed simply by replacing it with a new one, even while the device is in the vagina of a cow. The needle guidance system is incorporated into a new OPU device together with the transducer of an ultrasonographic scanner with an unilateral orientated scanning field, making it possible to utilize the needle length to its maximum. This combination permits easy manipulation of the ovaries, easy positioning of follicles on the puncture line, and enables the use of shorter needles which directly enter the scanned area without loss of useful needle length. As a preliminary result we obtained an overall oocyte recovery rate of 42%. Although this is promising, additional puncture sessions are needed to establish more consistent recovery rates. When OPU is used routinely, application of short disposable needles is more practical and economical.

The special silicone tube (50-120 mm in length) consists of three pieces. One piece is the thinner central segment [20-40 mm long, 0.64 mm outer diameter (OD), 0.30 mm inner diameter (ID)], and the other two are thicker bilateral segments (10-50 mm long, 0.94 mm OD, 0.51 mm ID). Both ends of the three-piece silicone tubing (TPST) were sealed by the silastic medical adhesive with or without the silicone rod (2 mm long, 0.5 mm diameter) and diagonally cut to taper the end. To push the TPST from the upper and lower puncta into the lacrimal passage, a thin metal probe (0.4-0.6 mm diameter) was inserted into both sides of the tube through a small cut. In this new technique, there is no difficult procedure of retrieving the tip of a metal probe from the nasal cavity. The TPST requires no suture to secure it in position. The success rates were 63.6% (7/11), 100% (5/5) and 50% (1/2) for nasolacrimal-duct obstruction, canalicular obstruction, and canalicular and nasolacrimal-duct obstructions, respectively (follow-up: 3.4-12 months, mean 5.3 months).

To the Editor: Sterile ascites after ventriculoperitoneal shunting is rare and usually of unknown cause.1 We describe a patient in whom an inflammatory reaction to silicone tubing used in the creat...

Introduction Efficacy and safety of devices for the endovascular recanalization of acute ischemic stroke (AIS) are mostly validated in experimental vascular models and in vivo animal models. Efforts have been made to develop mechanically stable clot models to explore the interactions between the clots and devices; however, little is known about the mechanical similarities between these clot models and the human sources of embolic thrombi. The aim of this study is to explore the structure and mechanical properties of the possible sources of the cerebral emboli extracted from patients and model clots produced in vitro using human, porcine and bovine donors. Materials and methods Six thrombi were collected during carotid endarterectomies (CEA) and two thrombi were obtained from the internal carotid artery (ICA) of AIS patients. In vitro clots were prepared by simultaneously injecting whole blood/ACD mixture and CaCl 2 /thrombin solution into silicone tubing. Three variables of in vitro clotting included species, thrombin concentration and addition of the radio-opaque component, barium sulfate. Dynamic mechanical analyzer was used to acquire the stress–strain behaviors of the clots in the controlled force mode which gave an indication of clot hardness. Clot elasticity was studied in stress–relaxation mode by recording the strain recovery. Scanning electron microscopy (SEM) and Martius Scarlet Blue stained sections were used to investigate the structure and composition of the specimens. Results Two secant moduli, designated E1 and E2, are calculated from the toe region (initial to 75% strain) and high strain (75–95%) of the stress–strain curve, respectively. The calcified thrombi from CEA (n=2) had lower elongation and higher moduli (E1=737.8±296.9 Pa, E2=12313±165.7 Pa) whereas red cell rich thrombi (n=4 from CEA and n=2 from ICA) showed higher elongation and lower moduli (E1=585.7±98.37 Pa, E2=6651±675 Pa). Interspecies differences in the mechanical properties of clot models were observed. Overall, bovine clots had the highest hardness followed by porcine and human clots. Addition of thrombin significantly increased E1 and E2 of the human and porcine clot models (p Conclusion In this research we move beyond studying composition of thromboemboli by additionally investigating the mechanical properties of these sources of AIS. As newer generations of endovascular recanalization devices become available, it will be important to create a variety of characterized clot models to study the safety and efficacy of the devices preclinically. More human cerebral thrombi will be analyzed to provide a library of mechanical properties to construct a framework for further development of clot models.

7 eases of 11 peripheral nerve defects (5 median nerves, 5 ulnar nerves, and 1 radial nerve) were repaired through artery-including silicone tubing. The nerves have gaps within 3 cm in 9, and 3 to 5 cm in 2. Repairing the defect’s location, 4 of them were below the axilla; 1 at the upper 1/3 part of the forearm and 6 at the lower part of the forearm. The duration of injuries was from 4 to 7 months, except one case lasting over a year. Six patients with 9 nerves involved had adequate follow-up of 6 to 9 months. One patient with 2 nerves was lost to follow-up. The results were excellent in 5 nerves (M4S3), good in 2 (M3S3), and poor in 2 (M1S1).

Although canalicular injuries are relatively common, controversy persists regarding indications for repair and the surgical methods that should be employed. In this review, these various treatment philosophies and techniques are analyzed in an historical and a contemporary context. The surgical anatomy, epidemiology and clinical presentation of canalicular injuries are discussed. Inconsistencies in current nomenclature regarding the surgical anatomy of canalicular lacerations are analyzed. Recent studies of lacrimal drainage in systems with monocanalicular obstruction are cited. Various surgical techniques in the repair of canalicular injuries are reviewed, including methods of identifying the medial lacerated lacrimal passages and the various lacrimal stents that have been used. The current popularity of silicone tubing as a lacrimal stent is reviewed. The various methods of stent placement and fixation are systematically categorized. Case series of canalicular repair reported in the literature are reviewed, and the results and complications are compared.

Silicone intubation of the canalicular system is indicated for stenting following canalicular trauma or surgery, or to dilate chronic stenosis of the punctum or canaliculus. Monocanalicular systems are available, but bicanalicular intubation is generally more stable and is particularly suitable for disease involving both the upper and the lower punctae or canaliculae. Bicanalicular intubation can be accomplished by intubating the entire lacrimal outflow system into the nose, or more simply by intubating the canalicular system alone using a pigtail probe. To use the pigtail probe to pass and fixate a segment of silicone tubing, the silicone tube is passed using a monofilament suture. A pre-swedged silicone tube segment on a monofilament suture has been designed to simplify the process of pigtail probe intubation of the canlicular system. [Ophthalmic Surg Lasers 1998;29:770-771.]

• We tested the security of laparoscopic, hemostatic clips in vitro and in vivo. In vitro, the force needed to transversely dislodge clips that were applied to silicone (Silastic) tubing ranged from a mean±SEM of 1.81 ±0.07 N (Endo Clip) to 2.68±0.04 N (Ligaclip). The force needed to axially dislodge clips that were applied to silicone tubing ranged from 4.08±0.20 N (Endo Clip) to 4.78±0.18 N (Ligaclip). In vivo, on mesenteric vessels in anesthetized pigs, 34 of 100 clips that were applied laparoscopically with the Endo Clip were moved or dislodged compared with 11 of 100 of those applied with the Ligaclip. We conclude that laparoscopically placed vascular clips applied with the Ligaclip are more secure than those applied with the Endo Clip. The laparoscopic surgeon should be aware of the relative ease with which clips may be dislodged. ( Arch Surg . 1992;127:718-720)

A section of migrated lacrimal silicone tubing was repositioned in a 7-year-old patient by dilating the lacrimal passage with hyaluronate solution and pushing the tube back into the nasal fossa with a probe. The position of the tube was postoperatively confirmed by ultrasonographic studies.

We performed 63 intubations with silicone tubing for nasolacrimal duct obstruction in children in whom nasolacrimal duct probings had failed. Fifty-nine (93.7%) obstructions were congenital and four (6.3%) were acquired. The average length of intubation was 4.3 months. The final results for both congenital and acquired obstructions combined were good in 52 cases (82.5%), fair in three (4.8%), and poor in eight (12.7%). Complications, with the exception of some with infection, were easily treated or minimal and did not affect the outcome significantly. We recommend silicone intubation as the procedure of choice for congenital or acquired nasolacrimal duct obstructions in children after failure of medical therapy and nasolacrimal duct probings.

We have developed an implantable venous catheter for repeated blood sampling in the Munich minipig. The catheter consists of silicone tubing, with a polyesterfibre net for fixation in the subcutaneous tissue of the neck. It was introduced into the right jugular vein, and its tip was positioned in the right atrium. The extravascular part of the catheter was tunnelled subcutaneously to the exit point in the subscapular region. In order to avoid contamination of the silicone tubing by drugs, intravenous administrations were performed via a second polyethylene catheter inserted into the implanted catheter. In 9 minipigs, the catheter remained patent for an average of 200 days (maximum 515 days). The animals did not show any signs of discomfort or impaired health.