A pilot study to evaluate the effectiveness of small intestinal submucosa used to repair spinal ligaments in the goat

BACKGROUND CONTEXT

Destabilization of the lumbar spine results from sacrifice of the anterior longitudinal ligament and disc when removed for graft or cage placement. In a similar fashion, transection of the interspinous ligament during surgical approaches to the posterior spine may result in segmental instability. Such instability can cause abnormal motion or implant migration resulting in a higher incidence of pseudarthrosis. Small intestinal submucosa (SIS) is a naturally occurring extracellular collagen-based matrix, which is derived from porcine small intestine. SIS contains cytokines and growth factors and has been shown to act as a resorbable scaffold in vivo that promotes host soft tissue regeneration with little scar tissue formation. SIS can be manufactured in laminated sheets of various sizes and thicknesses for different indications. Successful applications of SIS in animals have included dural substitution, rotator cuff repair, vessel repair, abdominal and bladder wall repair, and others. However, SIS has not been investigated to determine its ability to facilitate regeneration of spinal ligaments.

PURPOSE

The purpose of this pilot study was to evaluate the efficacy of SIS as a barrier to prevent interbody device migration, and to act as a scaffold for regeneration of the anterior longitudinal ligament (ALL) and posterior interspinous ligament (PISL) in a goat model.

STUDY DESIGN/SETTING

The thoracolumbar spine of the goat was exposed surgically. After resection and removal of the ALL or PISL at alternating levels, either SIS was placed or no treatment was administered. New ligament formation and SIS resorption were monitored over a 12-week period.

OUTCOME MEASURES

Plain film radiographs and histomorphometry were used to assess the progress of healing over a 12-week time period.

METHODS

Four skeletally mature nubian-alpine crossbred goats were used in this study. Under general anesthesia, each T10 to L5 motion segment was exposed surgically. Both anterolateral and posterior approaches were performed simultaneously at each level. Anteriorly, alternating levels received either 1) anterior discectomy, sacrifice of ALL and placement of SIS (SIS group); 2) anterior discectomy, sacrifice of ALL and no SIS (surgical control group) or 3) no surgical intervention (nonoperative group). A solid interbody spacer was placed into the disc space after discectomy to deter spontaneous anterior interbody fusion. Posteriorly, alternating levels were treated with either 1) sacrifice of the PISL with placement of SIS (SIS group); 2) sacrifice of PISL and no SIS (surgical control group) or 3) no surgical intervention (nonoperative group). The SIS was secured to the adjacent superior and inferior spinous processes to create a tension-band effect. Animals were radiographed immediately postoperatively to confirm placement of interbody spacers and anchors and to serve as a baseline for monitoring interbody spacer positioning. After surgery, all animals were allowed unrestricted motion for 12 weeks. At the end of the 12-week period, animals were radiographed and euthanized. The lumbar spine was harvested en bloc and processed for decalcified histologic evaluation. The dorsal and ventral aspects of each motion segment were analyzed for signs of inflammation and scar tissue formation, residual SIS and regenerated ALL or PISL.

RESULTS

All animals tolerated the surgical procedure well, and there were no intraoperative or anesthesia-related complications. Twelve-week radiographs showed some evidence of ventral migration of the interbody spacers in several animals. Fifty percent (two of four) of spacers in surgical control group levels had migrated more than 10 mm (resulting in complete migration out of the disc space), whereas no spacers migrated completely out of levels with SIS placed. Gross analysis at necropsy indicated iatrogenic scar formation at operated levels, the degree of which was not different from surgical control group to SIS levels. Histologic evaluation of areas where the ALL had been removed indicated formation of organized fibrilar collagenous tissue that spanned the disc space at some levels where the SIS was placed. In some cases, the newly formed tissue was approximately the thickness of the ALL at the nonoperative group levels. The newly formed collagenous tissue was accompanied by sparse focal areas of inflammation, with small fragments of residual SIS at some levels. At surgical control group levels, there was a varying degree of connective tissue that ranged from moderately organized to randomly oriented with no significant signs of inflammation. Similarly, histologic analysis of some levels where SIS was placed posteriorly showed formation of organized collagenous tissues where the PISL had been removed.

CONCLUSIONS

In this model, the SIS patch was sufficient to prevent acute ventral migration of interbody spacers from the disc space. The extent of long-term healing and new tissue formation in the SIS group indicates that it may be efficacious as a reparative intervention for transected ligaments in the spine. Most SIS specimens showed formation of organized collagenous tissue, indicating a long-term potential for ligament formation. However, in this model, 12 weeks of postoperative healing is insufficient to assess the full potential of SIS as a spinal ligament repair. Further research that follows the healing process to a longer time point postoperatively may be necessary to fully understand the potential of SIS as a resorbable scaffold for tissue replacement.

Effect of a capsular tension ring on intraocular lens decentration and tilting after cataract surgery

PURPOSE

To evaluate the effect of a capsular tension ring (CTR) on the tilting and decentration of intraocular lenses (IOLs) after cataract surgery.

SETTING

Department of Ophthalmology, Ilsan Paik Hospital, Inje University, Kyunggyi-do, Korea.

METHODS

Cataract surgery was performed in both eyes of 20 patients ranging in age from 57 to 75 years. The 40 eyes were divided into 2 groups based on whether a CTR (Lucid Korea) was implanted. Each patient received a CTR in 1 eye only. All IOLs (AcrySof MA60BM, Alcon) were implanted in the capsular bag after a continuous curvilinear capsulorhexis smaller than the IOL optic was created and phacoemulsification performed. The extent of IOL tilting and decentration was measured with the EAS-1000 anterior eye segment analysis system 7, 30, and 60 days after surgery.

RESULTS

The extent of IOL decentration was statistically significantly less in eyes with both an IOL and CTR than in those with an IOL only. The mean decentration in the CTR-IOL group was 0.38 mm +/- 0.16 (SD) at 7 days, 0.43 +/- 0.15 mm at 30 days, and 0.42 +/- 0.17 mm at 60 days. The mean values in the IOL-only group were 0.49 +/- 0.11 mm, 0.53 +/- 0.14 mm, and 0.57 +/- 0.16 mm, respectively. The amount of IOL tilting was also significantly less in the CTR-IOL group. The mean tilting in the CTR-IOL group was 2.22 +/- 0.46 degrees at 7 days, 2.36 +/- 0.50 degrees at 30 days, and 2.47 +/- 0.40 degrees at 60 days. The mean values in the IOL-only group were 3.14 +/- 0.65 degrees, 2.91 +/- 0.67 degrees, and 3.06 +/- 0.56 degrees, respectively.

CONCLUSION

These results indicate that the CTR reduces undesirable postsurgical IOL movement for at least 60 days.

A technique for safe withdrawal of a catheter tip that hooks a coil loop

In cerebral aneurysm embolization with GDCs, coil movement and subsequent coil protrusion or migration may occur during catheter withdrawal. Coil migration or protrusion usually does not produce clinical problems, but sometimes it may do. Because the consequences of coil movement cannot be anticipated exactly, coil motion during a catheter withdrawal makes interventionists nervous. The authors report on a technique for safe withdrawal of a catheter tip that hooks a coil loop using a small soft coil.

The Dretler stone cone: a device to prevent ureteral stone migration-the initial clinical experience

PURPOSE

Retrograde stone migration during ureteroscopic lithotripsy occurs in 5% to 40% of proximal and distal ureteral stone cases. This migration increases morbidity and the need for auxiliary procedures. The Dretler stone cone (Medsource, Norwell, Massachusetts) is a novel device to prevent proximal stone migration and facilitate fragment extraction during ureteroscopic lithotripsy. We assessed the safety and efficacy of the Dretler stone cone in the clinical setting and compared it prospectively with a conventional flat wire basket during ureteroscopy for ureteral calculi.

MATERIALS AND METHODS

To our knowledge we report the initial clinical use of the Dretler stone cone in 50 consecutive patients with ureteral calculi undergoing ureteroscopic extraction. Calculi were situated above the sacroiliac joint in 24 cases, over the sacroiliac joint in 15 and below the sacroiliac joint in 11. Pneumatic lithotripsy was done in 42 cases. In the remaining 8 cases ureteroscopic (3) or fluoroscopic (5) intact stone extraction was performed. The later 23 cases using the Dretler stone cone were prospectively compared with 20 of ureteroscopic intracorporeal lithotripsy using a standard flat wire basket.

RESULTS

The Dretler stone cone was successfully placed in all 50 cases. In 41 patients it was placed via cystoscopy under fluoroscopic guidance, while 9 impacted stones required ureteroscopic placement. Six patients in whom the Dretler stone cone was used had residual fragments less than 3 mm. No patient required auxiliary procedures. In the prospective trial no patients in Dretler stone cone group had residual fragments greater than 3 mm. or required auxiliary procedures. However, in the flat wire basket group residual stones greater than 3 mm. were present in 6 cases (30%, p <0.001), while auxiliary procedures were required in 4 (20%, p <0.01).

CONCLUSIONS

The Dretler stone cone represents a new generation of basketry that minimizes proximal ureteral stone migration and allows safe extraction of fragments during ureteroscopic lithotripsy. In our experience it is associated with a lower incidence of significant residual fragments and fewer auxiliary procedures than conventional flat wire baskets.

A randomised controlled clinical trial of antibiotic impregnation of testosterone pellet implants to reduce extrusion rate

OBJECTIVE

Testosterone pellet implantation is a safe, effective and convenient form of depot androgen replacement, with extrusion of pellets following about 10% of procedures the most frequent adverse effect. This study aimed to determine whether extrusion rate could be reduced by antibiotic impregnation of pellets immediately prior to implantation.

DESIGN

Prospective, randomised, parallel-group, open-label study design in a single centre. One hundred and eighty-six androgen-deficient men (400 implantation procedures) were randomised into either a group who had their pellets soaked for approximately 2 min in gentamicin solution prior to implantation, or a control group who had the standard implantation procedure.

METHODS

Extrusion, infection and/or bruising were evaluated prospectively by self-report from the participants, and retrospectively at subsequent implantation. Other variables (site, shaving, skin preparation, operator, pellet batch, bruising) were collected at implantation time.

RESULTS

The extrusion rate was 20% lower (odds ratio=0.80, 95% confidence interval (CI) 0.40-1.62) but not statistically different between the two groups (extrusion rate 23/205 (11.2%) for the control group vs 18/195 (9.2%) for the antibiotic-soak group, P=0.42). One operator experienced more total (P=0.0002) and infection-related (P=0.0008) extrusions and marginally more bruising (P=0.06) than other operators. The operator effect did not appear to be explained by differences in experience or implantation style. There was a 4.6-fold excess (95% CI 1.6-18.6) of multiple (19 vs 4 expected) over single (22 vs 10 expected) and no (359 vs 386 expected) extrusions. Extrusion was not related to batch number (P=0.15), location (P=0.15), shaving (P=0.32), old or new site (P=0.59), or the presence of suppuration or not (P=0.42); however, povidone-iodine skin disinfectant had statistically fewer extrusions than mixed alcohol solution.

CONCLUSIONS

Antibiotic impregnation prior to implantation does not significantly decrease testosterone pellet extrusion rate. An operator effect, not due to experience or procedural style, an excess of multiple extrusions and disinfectant effects were confirmed. Neither location, nor preparation of the site, nor pellet batch, influences extrusion rate.

Malignant gastric outlet obstructions: treatment by means of coaxial placement of uncovered and covered expandable nitinol stents

PURPOSE

To assess whether coaxial placement of uncovered and covered expandable nitinol stents overcomes the disadvantages of the increased migration rate seen with covered stents and the tumor ingrowth seen in uncovered stents in the treatment of malignant gastric outlet obstructions.

MATERIALS AND METHODS

Two types of expandable nitinol stent were designed: an uncovered stent and a covered stent. Under fluoroscopic guidance, the uncovered and covered stents were placed coaxially with complete overlap in 39 consecutive patients with malignant gastric outlet obstruction caused by stomach cancer. Food intake capacity was graded on a scale of 0-4. Stent patency rate was estimated by the Kaplan-Meier method.

RESULTS

Technical success rate was 97% (38 of 39 patients). After stent placement, food intake capacity improved at least one grade in 36 patients. Stent migration occurred in three patients (8%), that is, partial (n = 2) or complete (n = 1) upward migration of the inner covered stent into the stomach. Two of these patients were treated by placement of an additional covered stent. During the mean follow-up period of 134 days (range, 15-569 d), 10 patients developed recurrent symptoms of obstruction with tumor overgrowth being the most common cause. Nine underwent placement of an additional covered stent with good results. The median period of primary stent patency was 157 days (mean, 278 d). The 30-, 60-, and 180-day patency rates were 97%, 91%, and 39%, respectively. Four patients (10%) died within 1 month after the procedure.

CONCLUSION

Coaxial stent placement technique seems to contribute to decreasing the migration rate of the stent and decrease the rate of recurrent obstruction by preventing or delaying tumor ingrowth.

Primary banked scleral patch graft in the prevention of exposure of hydroxyapatite orbital implants

PURPOSE

The most frequently reported complication of hydroxyapatite orbital implantation is exposure of the implant, which may result in infection or extrusion of the implant. This study describes the use of banked sclera patch grafts to prevent implant exposure.

DESIGN

A retrospective noncomparative interventional case series.

PARTICIPANTS

The procedure was performed on 110 patients over a 2-year period. Hydroxyapatite implantation was performed either at the time of enucleation or as a secondary procedure to correct postenucleation socket syndrome.

INTERVENTION

A banked scleral patch graft from the second eye of the same donor was placed over a scleral-wrapped hydroxyapatite implant at the time of operation. The case records were reviewed retrospectively.

OUTCOME MEASURES

The primary outcome measure was the number of patients who developed exposure of their hydroxyapatite implant. The number of patients who had a postoperative conjunctival wound dehiscence was also recorded.

RESULTS

No patients developed exposure of the implant. A significant percentage of patients developed conjunctival wound dehiscence (33%). Further surgery was not required in any of these cases, because the dehiscence spontaneously reconjunctivalized over the surface of the scleral patch graft.

CONCLUSIONS

Insertion of a banked scleral patch graft at the time of hydroxyapatite orbital implantation is an effective means of preventing implant exposure, even in more complex cases. It thereby reduces the morbidity resulting from the procedure and obviates the need for further surgery when there is breakdown of the conjunctival wound postoperatively.

Injizierbares Silikon

The injection of fluid silicone was formerly an acceptable therapy for recontouring post-traumatic or age-related changes of the face and neck. About 20 years after the use of silicone injections, the number of patients presenting with late complications is increasing. Such complications include migration of the silicone, granuloma formation, chronic cellulitis, skin ulcers and and scarring, all of which are difficult to treat medically or surgically. Recent data in the literature support the notion that fluid silicon is a potential carcinogen. These patients require a careful approach combining the limited surgical possibilities with the support needed to live with such a problem. Using a case report as an example, we discuss the diagnostic and therapeutic problems associated with this phenomenon which is relatively uncommon in Europe.

Optimal prevention and management of proximal ureteral stent migration and remigration

PURPOSE

We evaluated issues associated with proximal ureteral stent migration and remigration, including causes and management, and the predictability of ureteral length.

MATERIALS AND METHODS

All proximal ureteral stent migrations that occurred from January 1997 to March 2000 were reviewed. Characteristics and treatment of the 33 patients with proximal ureteral stent migration were compared with those of 66 randomly selected controls who did not have stent migration. We also analyzed a subgroup of 6 cases of remigration.

RESULTS

Of the ureteral stents 2% migrated proximally. Mean height was greater in patients with versus without a migrated stent (p = 0.028). The stent-to-ureter length ratio was lower in the migrated than in the nonmigrated group (p <0.0001). Patient height and side of migration were significant predictors of ureteral length (R2 = 0.3511, p <0.0001 and 0.0007, respectively). Of the patients who required continued ureteral stenting migrated stent management included placement of a longer stent in 9 (group 1) and a stent of equal length in 4 (group 2), and repositioning of the original stent in 4 (group 3). There was no remigration in group 1. However, migration recurred in 2 patients in group 2 (50%) and in all 4 in group 3 (100%).

CONCLUSIONS

Proximal migration occurs when a stent is too short for the ureter. We recommend that ureteral length should be measured directly from an x-ray to select the optimal stent length. If it is necessary to continue stenting a ureter after migration has been detected, a longer stent should be placed.

The effect of the Lockit epidural catheter clamp on epidural migration: a controlled trial

We investigated the efficacy of using the Lockit epidural catheter clamp in preventing epidural catheter migration in patients receiving postoperative analgesia via an epidural infusion after major surgery. Patients were randomly allocated to receive either a standard epidural dressing, a coiled catheter with transparent adhesive dressing and tape (n = 54), or the Lockit epidural catheter clamp (n = 48). There was no movement from the insertion position in 88% of the Lockit group compared with only 28% in the standard group (p < 0.001). Outward migration of > 2 cm occurred in 26% of the standard group compared with just 6% of the Lockit group (p < 0.01). Inward migration of > 1 cm occurred in 17% of the standard group but in none of the Lockit group (p < 0.01). Catheter migration was assessed as being the cause of analgesic failure in 15% of the standard group but in only 4% of the Lockit group (p < 0.05). We conclude that the Lockit epidural catheter clamp significantly reduces catheter migration in a safe and non-invasive fashion.

A simple technique for preventing bar displacement with the Nuss repair of pectus excavatum

BACKGROUND/PURPOSE

The most common complication of the minimally invasive technique for repair of pectus excavatum (MIRPE) is bar displacement, which has been reported to occur in 9.5% of all cases, particularly in teenaged patients. The use of a lateral stabilizing bar has improved stability but has not eliminated the occurrence of this problem. The authors report a new technique added to the standard MIRPE that creates an additional third point of fixation of the pectus bar to prevent displacement.

METHODS

The technique requires the simple placement, via a spinal needle, of a nonabsorbable suture next to the sternum, encircling a rib and the bar, using a single 3-mm stab wound and thoracoscopic guidance. The suture simply is buried under the skin. Since 1998, this technique has been applied to 20 patients who underwent MIRPE.

RESULTS

The average age was 14 years; 80% were boys. Average operating time was 75 minutes, and all patients had thoracoscopy with the MIRPE. A lateral stabilizing bar also was used in 14 patients. Four patients had 2 struts placed. Average length of stay was 5.5 days. There were no early complications. Mean follow-up was 12 months. Bar displacement occurred in 1 patient early in the series in which an absorbable suture was used for fixation. One patient had a prolonged hospital stay of 7 days because of postoperative pain.

CONCLUSIONS

This modification to the original technique of MIRPE creates a 3-point fixation system that minimizes the risk of bar shifting even in teenaged patients. It does not add any significant time or cost to the operation, and it is fairly simple to perform. The authors believe that this technique decreases the occurrence of bar displacement, and they recommend its use for all patients with pectus excavatum considered candidates for the Nuss repair.

PICC securement: minimising potential complications

Peripherally inserted central catheters are used for a variety of parenteral therapies. This article discusses the advantages of securing these catheters and different methods of securement.

Biomechanical evaluation of Hackethal's intramedullary bundle pin fixation of humeral neck fractures

Humeral neck fractures can be stabilized using a bundle of intramedullary pins as described by Hackethal. In order to decrease the risk of pin migration, packing of the medullary cavity with as many pins as possible is sometimes recommended, but others believe that stability can be decreased by destruction of cancellous bone in the humeral head by a large bundle of pins. A surgical neck fracture was created with a saw in 30 frozen cadaveric humeri. Bone quality was evaluated by radiography and densitometry. Fractures were stabilized using Hackethal's technique of retrograde intramedullary pinning with varying numbers of 2.5-mm diameter pins; increasing torsion or bending moments of force were then applied to the bones studied. Stability was found to improve with an increasing number of pins and with higher humeral head density. Based upon these findings, the use of a large number of pins is recommended to reduce the risk of pin migration. Up to eight pins, the risk of destruction of cancellous bone in the humeral head appears very low.

Intrapartum epidural catheter migration: a comparative study of three dressing applications

We compared three types of catheter fixation application for their ability to minimize the incidence and magnitude of epidural catheter movement during labour. Patients were randomized to have their epidural catheter secured by a Tegaderm dressing (group T; n = 35), a Tegaderm dressing plus filter-shoulder fixation (group F; n = 39), or a Niko Epi-Fix dressing (group N; n = 37). The length of catheter visible at the patient's skin surface was recorded (to the nearest 0.5 cm) after insertion and before removal; the difference was defined as 'catheter movement'. Outward movement of the catheter was greatest when a Niko Epi-Fix was used (P < 0.01). Concerning minimization of displacement of the epidural catheter per se, only a Tegaderm dressing with additional filter-shoulder fixation proved more effective than using a Niko Epi-Fix dressing (P < 0.05).

Securing cochlear implants to the skull: two alternate methods

In view of the various problems encountered with the traditional methods of securing cochlear implants--including dural tear and suture dissolution following infection--we devised two alternate methods of performing this procedure. We use a titanium mesh or a Gore-Tex patch secured with two 4-mm screws to fix the receiver to the skull. No patient who has undergone either of these procedures at our institution has experienced any of the complications that are associated with the older silk, nylon, and Dacron sutures. Moreover, our two alternate methods are less technically difficult and can be performed in a shorter period of time.

The role of peritoneal dialysis catheter configuration in preventing catheter tip migration

Migration of the peritoneal dialysis (PD) catheter from the pelvis to the upper abdomen frequently results in peritoneal dialysis failure and removal of the catheter. Previous studies compared PD catheter survival in various catheter configurations. These studies included single-cuff and double-cuff, straight-end and curled-end catheters, and showed an incidence of catheter migration ranging from 5%-35% depending on the catheter type. Recent studies demonstrated that the double-cuff, Swan-neck, curled-end configuration is associated with a considerably lower incidence of migration. Most of these studies, however, had a small patient sample or no control group, or they compared nonequivalent catheters (for example, Swan-neck, curled-end versus straight, non-curled-end). Over a six-year period, we examined two similar double-cuff, curled-end catheters: Group I catheters had a straight segment between the two cuffs, and Group II catheters had a 60 degrees Swan-neck bend between the two cuffs (Quinton Instrument Co., Bothell, WA, U.S.A.). The two catheters were identical, except for the presence or absence of the Swan-neck bend. All catheters were placed by the closed laparoscopic technique. In the two groups of patients in whom the catheters were implanted, no statistically significant difference was observed in primary disease, age, sex, race, weight, prior abdominal surgery, or duration of dialysis before catheter migration. In group I, 33 of the 219 patients developed catheter migration (15%); in group II, 2 patients of 243 patients developed catheter migration (less than 1%, p = 0.002). In conclusion, the Swan-neck configuration presents an independent factor in preventing PD catheter migration. Review of previous studies and the data from our study, show that double-cuff, curled-end, Swan-neck PD catheters are superior to other catheters in regard to prevention of catheter migration and should be the catheter of choice in PD patients.

Fixation of infrarenal aortic stent-grafts using laparoscopic banding -- an experimental study in pigs

PURPOSE

to test whether a laparoscopically-placed external band around the infrarenal aorta could stop vessel dilatation and prevent stent-graft detachment from the aortic wall.

METHODS

in 13 growing pigs Gianturco-based stent-grafts were placed in the infrarenal aorta. In eight pigs, an external PTFE band (1 cm width) was placed laparoscopically around the infrarenal aorta. The remaining five pigs served as controls. Angiographic aortic diameters were measured: (1) at the most distal renal artery; (2) 1.5 cm further distally; (3) at the middle of the stent-graft; and (4) below the stent-graft, 1 cm above the aortic bifurcation.

RESULTS

at a median follow-up of 16 weeks the pigs in the control group (n =5) and in the banded group ( n =7) increased their weight from 24 kg to 107 kg and 23 to 83 kg, respectively. In the control group, aortic dimensions increased by approximately 40% at all levels. In the banded group, aortic dimensions were unchanged at levels 2 and 3, but increased significantly at levels 1 and 4 (i.e. above and below the stent-graft). In the control group all stent-grafts detached causing a proximal perigraft leakage. No detachment or proximal perigraft leak was observed in the banded group.

CONCLUSION

a laparoscopically placed external band around the infrarenal aorta of growing pigs seems to counteract the vessel dilatation and thereby provides a stable fixation of self-expandable stent-grafts.

Effect of large positioning holes on capsule fixation of plate-haptic intraocular lenses

PURPOSE

To compare the centration and fixation of silicone plate-haptic intraocular lenses (IOLs) with different-sized positioning holes.

SETTING

Eye Clinic of the Johannes Gutenberg-University Mainz, Mainz, Germany.

METHODS

In a prospective randomized study, 51 Chiroflex C10 and 56 Chiroflex C11 IOLs were implanted under standardized conditions by the same surgeon. The IOL position was documented at the end of surgery and by retroillumination on the first day and 5 months postoperatively. The positioning-hole area was evaluated by ultrasound biomicroscopy (50 MHz) 5 months postoperatively.

RESULTS

One day postoperatively, no IOL in either group was decentered more than 1.0 mm. After 5 months, 33% of the C10 and 42% of the C11 IOLs were decentered between 0.5 and 1.0 mm, and 11% of the C10 and 8% of the C11 IOLs were decentered more than 1.0 mm (maximum 1.23 mm and 1.41 mm, respectively). Up to the first postoperative day, 20% of the C10 and 22% of the C11 lenses were rotated more than 15 degrees. At 5 months, an additional 15% of the C10 and 19% of the C11 lenses were rotated. Ultrasound biomicroscopy showed no tissue or capsule adhesion in the holes in most cases (85% C10 group; 71% C11 group). No difference was statistically significant.

CONCLUSIONS

Larger positioning holes did not prevent IOL decentration or rotation; thus, this IOL design appears unsuitable for correcting astigmatism. Because tissue in the positioning hole was rare with both lens types, it is doubtful that enlarged plate-haptic perforations will prevent IOL luxation into the vitreous cavity after capsulotomy.

Epidural catheter fixation: subcutaneous tunnelling with a loop to prevent displacement

A method of fixing the epidural catheter by subcutaneous tunnelling and looping was devised. A prospective, randomised, double-blind, clinical trial was conducted in 68 adult patients, where postoperative pain relief was planned by thoracic epidural analgesia. In the tunnelled group (n = 34), the epidural catheter was fixed with a subcutaneous tunnel and loop, whereas in controls (n = 34), a simple loop of epidural catheter was left over the skin without tunnelling. An adhesive dressing was used to secure the epidural catheter. We observed that catheter dislodgement occurred in only one patient in the tunnelled group compared to seven control patients (21%). Despite local inflammation of the skin around the tunnel in nine patients (27%), no catheter infection (positive culture tip) was found in patients with subcutaneous tunnelling for the extended period of 4-5 days. The method described allows the catheter to lie flat on the skin and outward traction of the catheter during movement of patients is dampened by the interposed loop which protects it against dislodgement. At the time of removal, both ends of the catheter can be removed under direct vision. In conclusion, we recommend this fixation method in cases where epidural analgesia is to be used for postoperative pain relief.

Posterior capsule tear with plate-haptic silicone intraocular lens dislocation

We report a case of posterior capsule rupture and posterior dislocation of an intraocular lens (IOL) caused by the tip of a silicone plate-haptic lens. The dislocation occurred during IOL implantation after uneventful phacoemulsification in a patient with a small pupil. Discussed are the possible reasons for the complication and measures to prevent it.

Ureteroscopy for proximal ureteral calculi: prevention of stone migration

BACKGROUND

The cephalad migration of proximal ureteral calculi accounts for a high percentage of ureteroscopic failures.

PATIENTS AND METHODS

A balloon on a wire is a single-channel 0.038-inch hollow guidewire with a low-profile balloon, which is inflatable to 12F. Forty-two consecutive patients with proximal ureteral calculi underwent ureteroscopy with the aid of this device.

RESULTS

Twenty-nine patients had successful placement of the balloon on a wire above the stone. Of those 29 patients, 26 became stone free with a single procedure.

CONCLUSION

The balloon on a wire is a useful tool to aid in the prevention of proximal ureteral stone migration during ureteroscopy and to minimize the number of secondary procedures. In addition, it appears to be cost-effective.

Long-term results of the foldable CeeOn Edge intraocular lens

PURPOSE

To determine the long-term efficacy and safety of the foldable silicone CeeOn Edge(R) model 911 intraocular lens (IOL).

SETTING

Eye Clinic, Klinikum Minden, Germany.

METHODS

A high-refractive-index silicone lens with a sharp edge was implanted after phacoemulsification in 42 eyes of 36 patients. Best corrected visual acuity (BCVA) and occurrence of complications were evaluated during a 3 year follow-up.

RESULTS

No significant postoperative complications were seen. At 3 years, 26 eyes of 22 patients were available for examination. The BCVA was 0.5 (20/40) or better in 92% of eyes and 1.0 (20/20) or better in 39%. No posterior capsule opacification (PCO) was observed, and neodymium:YAG capsulotomy was not indicated in any patient.

CONCLUSIONS

This pilot study indicates that the performance and safety of the foldable silicone CeeOn Edge lens are excellent. The results support the theory that a sharp edge on the IOL prevents the development of PCO.

The effect of intramedullary bone plug on femoral stem migration of hydroxyapatite-coated hip arthroplasty

This study investigated the effect of intramedullary corticocancellous bone plug on the fixation and stability of hydroxyapatite-coated femoral stems in total hip arthroplasty (THA). Intramedullary corticocancellous bone plug was used in 30 patients with hydroxyapatite-coated femoral stems (group A) and a consecutive series of 30 patients with hypdroxyapatite-coated stems without bone plug served as the control group (group B). Patients underwent clinical and radiographic follow-up for at least 2 years. The addition of corticocancellous bone plug to the hydroxyapatite-coated stem significantly improved clinical and radiographic results. The mean Harris Hip Score at 3 and 6 months postoperatively was 92 and 94 in group A, and 84 and 87 points in group B (P<.004 and P<.001, respectively). There was no significant difference between groups at 1 year postoperatively and thereafter. The predominant cause for the difference was the thigh pain score, which was reduced at both 3 and 6 months in group A compared to group B (P<.01 and P<.05, respectively). There also were statistical differences between the two groups regarding radiographic signs. The evidence of endosteal bone formation in group A patients was superior at 3 and 6 months (P<.001 and P<.01, respectively). The appearance of a radiolucent line was significant in group B patients at 3 and 6 months (P<.001). Femoral stem migration of 3 mm was noted in three group B patients versus no group A patients (P<.05). These short-term clinical and radiographic results suggest corticocancellous bone plug can provide early pain relief and durable implant fixation, but long-term follow-up should be considered.

Intraocular lens implantation in Marfan's syndrome

PURPOSE

To describe the results of the removal of ectopic lenses from patients with Marfan's syndrome using the scleral fixation method.

METHODS

Intraocular lenses (IOLs) were implanted in six eyes affected by lens dislocation (ectopia lentis) using either the scleral fixation method (five eyes) or a silicone IOL in the capsular bag (one eye). Mean patient age ranged from 8-11 years and follow-up ranged from 7-20 months.

RESULTS

Functional success was obtained in all eyes. Postoperative visual acuity was 20/20 to 20/40. One patient showed a dislocation of the IOL in the anterior chamber. In three eyes, an opacification of the posterior capsule was treated using an Nd:YAG laser.

CONCLUSION

Intraocular lens implantation using the scleral fixation technique is the first choice in patients with Marfan's syndrome because it reduces the complications of IOL decentration.

Migration of polyethylene particles around stable implants in an animal model

The aim of this study was to test the hypothesis that a tight seal between bone and implant will eliminate the avenue of particle migration around stable implants. Three types of implants were used in rabbits (polished press-fit Ti-6Al-4V or plasma-sprayed hydroxyapatite [HA]-coated Ti-6Al-4V) or doughy stage polymethyl methacrylate (PMMA). Implants were placed in the condylar notch. Each animal received an intra-articular injection of high density polyethylene (PE) particles (10(8) in 0.4 mL; mean size 4.7 microns) at 4 and 6 weeks postoperatively. Eight weeks postoperatively, peri-implant tissues were examined for PE particles and osteolysis. In all cases, intracellular PE particles were seen at the bone-implant interface and within marrow. No osteolysis was observed. Bone apposition was determined by computerized image analysis. There was no significant difference in the percentage of bone apposition (+/- SD) among the three groups of implants: Ti-6Al-4V (68% +/- 19%), HA-coated Ti-6Al-4V (70% +/- 10%), and PMMA (59% +/- 12%). These results indicate that a polished Ti-6Al-4V surface is as effective as PMMA or HA coating in limiting migration of PE particles around stable osseointegrated implants in rabbits.

Role of optic capture in congenital cataract and intraocular lens surgery in children

PURPOSE

To evaluate the role of optic capture in eyes having cataract extraction, anterior vitrectomy, and intraocular lens (IOL) implantation for congenital cataract.

SETTING

Iladevi Cataract & IOL Research Centre, Ahmedabad, India.

METHODS

This prospective study comprised 40 eyes of 28 children, whose mean age was 26.08 months (range 4 to 55 months). Primary posterior continuous curvilinear capsulorhexis, anterior vitrectomy, and IOL implantation were performed in all eyes. Eyes were randomly assigned to 1 of 2 groups of 20 each: in 1 group, optic capture would be used and in the other, the noncapture technique. Permanent optic capture was achieved in 14 eyes, and 26 eyes had no optic capture. Mean follow-up was 16.53 months (range 5 to 24 months). A Student t test and chi-square test were used for statistical analyses.

RESULTS

All eyes in both groups maintained a clear visual axis. One eye in the optic-capture group developed a membrane in front of the IOL that required a secondary procedure. Posterior synechia formation was significantly greater in the optic-capture group (P =.04), as were deposits on the IOL optic (P =.0086). Although all eyes in both groups maintained a clinically centered IOL, geometric decentration was more common in the no-capture group (P =.0000).

CONCLUSION

Optic capture resulted in better IOL centration but predisposed the eye to an increased uveal inflammatory response.

Endovascular stent-graft deployment: temporary vena caval occlusion with balloons to control aortic blood flow-experimental canine study and initial clinical experience

Vena caval occlusion was evaluated in animal experiments. In five patients with thoracic aortic aneurysms, two balloon catheters were introduced via the femoral vein to the inferior vena cava and superior vena cava and inflated before stent-graft deployment. Aortic pressure and flow were immediately decreased, which minimized the downstream shift of the stent-grafts. Temporary vena caval occlusion is safe and effective for precise aortic stent-graft deployment.

[Migration of the catheter of a totally implantable venous system. A rare mechanical complication]

Catheter migration, represents a rare, mechanical complication following the use of totally implantable venous devices. A case, in which the catheter was inserted into the right internal jugular vein by percutaneous route, without radiological control, is described. Following the chemotherapy infusion drugs, the patient developed a catheter displacement and subcutaneous extravasation. Etiological hypotheses and modalities of prevention are discussed.

Repeated subarachnoid catheter displacement as a complication of spinal infusion using an internal infusion pump

OBJECTIVE

To present and analyze the case of a woman receiving chronic spinal opioid therapy using an implanted infusion pump who experienced repeated displacement of the subarachnoid catheter despite the use of standard techniques for anchoring the catheter. The solution devised to avoid the problem is described.

CASE REPORT

A 53-year-old woman was diagnosed with transverse myelitis 10 years earlier and she developed T7-T10 spinal cord atrophy, and pain below the T7 segment. After unsuccessful noninvasive pharmacological treatment, a spinal opioid infusion protocol was begun. On 3 occasions during the course of therapy, despite the use of standard measures for anchoring the system, catheter displacement into the subcutaneous pouch of the pump occurred. After the last such episode, a specially designed technique was used, anchoring the catheter by means of a silicone piece, and the injection of 2.5 mL of fibrin glue in the epidural space.

CONCLUSIONS

The application of fibrin glue (Tissucol; Immuno AG, Vienna, Austria) may be considered as an adjuvant for the fixation of subarachnoid catheters used for intraspinal infusions.

A technique to prevent newly implanted stent displacement during subsequent catheter and sheath manipulation

We describe a novel technique to prevent the displacement or migration of a newly implanted stent as a consequence of any subsequent catheter and sheath manipulation during the same catheterization procedure. The technique involves reinflation of the dilation balloon within the stent immediately after implant followed by advancing the long delivery sheath carefully over the balloon as the balloon is slowly deflated within the stent. The technique was used successfully in 78 stents in 30 patients without stent dislodgment or migration.

The self-locating catheter: clinical evaluation and comparison with the Tenckhoff catheter

BACKGROUND

Peritoneal catheter displacement appears to be related to various causes including omental attachment, bowel contractions, peritoneal adhesions, and the catheter floating in the dialysis fluid. In order to prevent this complication, which can impair peritoneal dialysis efficacy, Di Paolo et al. designed a "self-locating catheter" (SLC) that is similar to the Tenckhoff catheter (TC) and includes a small tungsten cylinder (weight 12 g) at the distal end (Di Paolo N, et al. The self positioning catheter. Proceedings of the VII Italian Congress on Peritoneal Dialysis. Milan: Wichtig Editore, 1993:539-42). The weight of the tip prevents the catheter from floating and migrating by gravitation toward the Douglas cavity.

OBJECTIVE

Starting in 1996, we implanted SLC in 15 continuous ambulatory peritoneal dialysis patients. The aim of our study was to compare the ratio of migration and other catheter-related complications between patients with SLC (196 patient-months) and 13 patients with conventional straight TC (295 patient-months).

RESULTS

Peritonitis ratio, catheter complication rate, dialysate inflow and outflow, and weekly creatinine clearance were similar in the two groups of patients. The incidence of catheter displacement was significantly higher (p = 0.0349) in theTC group than in the SLC group (4 vs 0).

CONCLUSION

In our experience, the SLC seems to be useful in preventing catheter migration by continuous gravitation of its extremity toward the pelvic cavity.

Mid-term fixation stability of the EndoVascular Technologies endograft. EVT Investigators

AIM OF THE STUDY

to determine the positional stability of the EndoVascular Technologies (EVT) endograft after endovascular aneurysm repair during morphologic changes of the abdominal aorta during follow-up.

PATIENTS AND METHODS

all patients treated worldwide with an EVT endograft with an adequate postoperative and at least 12 months postoperative CT scan were included (n=125). Endograft migration was investigated by recording the position of the endograft attachment systems relative to the renal arteries and the aortic or iliac bifurcations. The vertical body axis served as a scale to quantify migration. Aortic cross-sectional areas were measured in the suprarenal aorta and in the proximal and distal aneurysm necks. Length changes of the infrarenal aorta during follow-up were measured, comparing the distance between the left renal artery and the aortic bifurcation.

RESULTS

the median follow-up was 24 months (range 12-48 months). Graft migration was identified in 4 out of 125 patients (3%). Significant infrarenal aortic dilation was observed at the proximal and distal aneurysm neck during follow-up. However, aortic neck dilation was not associated with endograft migration. The length of the infrarenal aorta did not change significantly after endovascular repair.

CONCLUSION

fixation by stents containing hooks of the EVT design appear to be effective in preventing migration of endografts with an unsupported trunk for up to four years. A stable position was maintained in spite of changes in cross-sectional areas of the aneurysm neck.

Update on fixation of rigid and foldable posterior chamber intraocular lenses. Part I: Elimination of fixation-induced decentration to achieve precise optical correction and visual rehabilitation

PURPOSE

Realizing that precise posterior chamber intraocular lens (PC-IOL) centration is needed to consistently achieve good optical results and visual rehabilitation after modern cataract surgery, the authors assessed the status and success rate of lens haptic fixation and its correlation with lens optic centration-decentration in a large series of eyes with PC-IOLs obtained postmortem.

DESIGN

Prospective analysis of pseudophakic eyes obtained postmortem.

PARTICIPANTS

A total of 3493 human eyes obtained postmortem, the largest database of such specimens available to date.

METHODS

Miyake-Apple posterior photographic technique.

MAIN OUTCOME MEASURES

The amount of decentration of rigid PC-IOLs and small-incision foldable PC-IOLs was analyzed, and the results were correlated with the type of fixation that had been achieved in each case.

RESULTS

Determination of mean values revealed that capsular bag fixation was achieved in 52.05% of eyes, asymmetric bag-sulcus fixation in 34.21 % of eyes, and sulcus-sulcus fixation in 13.74% of eyes. Asymmetrically fixed lenses consistently showed significant decentration. During the past 5 years (1993-98), the overall rate of in-the-bag fixation increased to 59.2%; by 1998 it had increased to 64%. Most significantly, success in achieving bag-bag fixation of foldable IOLs implanted in association with modern capsular surgery with small incisions has surged to 90% over the past 4 years.

CONCLUSIONS

The authors found a direct correlation of decentration in eyes with asymmetric fixation, and the results underscore the need for careful in-the-bag haptic placement. Although few surgeons today would dispute the goal to implanting haptics in the capsular bag, these findings show that the overall success rate over the years has, while improving, remained surprisingly low. The overall success rate of about 60% seen with all lens designs is probably as good as can be expected with classic large-incision extracapsular techniques. However, and most important and encouraging, the success rate of haptic fixation in cases with foldable lenses has improved dramatically during the past 4 years (up to the 90% range). This coincides with the present emphasis on modern capsular surgery and small-incision techniques used to insert these lenses.

Endovascular repair of a descending thoracic aortic aneurysm: a tip for systemic pressure reduction

A proposed technique for systemic pressure reduction during deployment of a stent graft was studied. A 67-year-old man, who had a descending thoracic aneurysm, was successfully treated with an endovascular procedure. An occluding balloon was introduced into the inferior vena cava (IVC) through the femoral vein. The balloon volume was manipulated with carbon dioxide gas to reduce the venous return, resulting in a transient and well-controlled hypotension. This IVC-occluding technique for systemic pressure reduction may be safe and convenient to minimize distal migration of stent grafts.