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Surgical management of vitreomacular traction syndromes.

A series of 106 consecutive symptomatic eyes considered to be at high risk for idiopathic macular holes developing underwent pars plana vitrectomy with membrane peeling. One of three types of vitreomacular traction was noted intraoperatively in all the eyes. The elimination of the vitreomacular traction resulted in improved vision in 89% of the eyes, no change in 7%, and decreased vision in 4%. A total of 62% of the patients were women (median age, 67 years). Follow-up ranged from 6 months to 118 months (average, 35 months). Complications included accelerated nuclear sclerosis in 16% and a 2% incidence of retinal detachment, macular pucker, and macular holes.

Adult↗

Results of vitrectomy for diabetic traction retinal detachments using the en bloc excision technique.

En bloc excision is a technique in which fibrovascular diabetic membranes and the posterior hyaloid are separated from the retina as a single unit. In a consecutive series of 69 eyes with diabetic traction retinal detachment treated with this technique, initial retinal reattachment was accomplished in 100% (69/69) of the eyes. With a minimum of 6 months' follow-up, the retina remained completely attached in 83% (57/69) of eyes, while the macula was attached in 88% (61/69) of eyes. Final visual acuity was 5/200 or better in 71% (49/69) of eyes. While current surgical techniques allow a high rate of anatomic success in the repair of diabetic traction retinal detachment, visual results remain limited by irreversible alterations in retinal function.

Adolescent↗

A modified en bloc excision technique during vitrectomy for diabetic traction retinal detachment. Results and complications.

PURPOSE: The visual results and complications were determined for a modified en bloc excision technique for management of diabetic traction macular detachment. PATIENTS AND METHODS: A consecutive series of 30 eyes with this condition underwent pars plana vitrectomy, during which all posterior hyaloid except for portions essential for membrane dissection were excised. Bimanual dissection techniques then allowed excision of fibrovascular membranes "en bloc" with the retained hyaloid. RESULTS: After 6 to 44 months of follow-up, visual acuity of 5/200 or better was obtained in 23 (77%) of 30 eyes, with complete reattachment in 29 (97%) of 30 eyes. Iatrogenic retinal breaks occurred in 6 (20%) of 30 eyes. Two eyes required repeat vitrectomy. CONCLUSIONS: The modified en bloc excision technique allowed similar visual outcome, a higher reattachment rate, and less postoperative morbidity than previously reported surgical approaches to diabetic traction macular detachment.

Adult↗

Intrapapillary and peripapillary hemorrhage in young patients with incomplete posterior vitreous detachment. Signs of vitreopapillary traction.

PURPOSE: The authors describe a benign condition characterized by intrapapillary and subretinal peripapillary hemorrhage, incomplete posterior vitreous detachment with persisting attachments to the disc, and preservation of optic nerve function in young patients. METHODS: Eight patients 11 to 42 years of age with no or mild symptoms (blur, spot, or smudge) were referred for disc hemorrhage; seven of these patients were Asian. All underwent complete ophthalmologic examination, including detailed slit-lamp microscopy; particular attention was paid to vitreous attachments. RESULTS: Superficial hemorrhage occurred predominantly in the superior hemidisc and was often striking in appearance. Subretinal hemorrhage occurred at the superonasal disc margin in six patients and was centered inferonasally in two. Discs were generally small, mildly dysplastic, and tilted; all were mildly elevated. The posterior vitreous body was separated from the retina but remained attached to the disc. Six patients had subtle visual field abnormalities in the involved eye. The hemorrhages resolved without sequelae or impairment of vision. During a 6-month follow-up, no patient progressed to complete vitreous detachment, retinal tear, or retinal detachment or required surgery to release traction. CONCLUSION: The authors postulate that vitreopapillary traction traumatized disc vessels, causing hemorrhage in and around the disc. The superior hemidisc received the shearing force of detachment, which tore superficial vessels; transmission of the force through the retina caused subretinal bleeding. Posterior vitreous detachment remained incomplete because of tenacious vitreopapillary attachments. Mildly dysplastic discs, as in the young patients with myopia reported here, may have unusual vitreous attachments, predisposing them to the occurrence of and trauma from premature vitreous separation. The condition described is benign and requires no further evaluation or intervention.

Adult↗

Tractional retinal detachment after branch retinal vein occlusion. Influence of disc neovascularization on the outcome of vitreous surgery.

OBJECTIVE: This study aimed to investigate the influence of disc neovascularization on the outcome of vitreous surgery for tractional retinal detachment (TRD) after branch retinal vein occlusion (BRVO). DESIGN: The study design was a retrospective case series. PARTICIPANTS: Twenty-two eyes of 22 patients who had undergone vitrectomy for TRD after BRVO at the Osaka National Hospital (Osaka, Japan) or the Surugadai Hospital of Nihon University (Tokyo, Japan) between 1985 and 1995 participated. Seven (32%) of 22 eyes had a TRD secondary to neovascularization of the optic disc (NVD) and neovascularization elsewhere (NVE; group I), and 15 (68%) had a TRD with NVE without NVD (group II). MAIN OUTCOME MEASURES: Visual acuities and retinal reattachment rates were measured. RESULTS: Sixteen (73%) of the 22 study eyes showed severe vitreous hemorrhage before surgery, and 11 eyes (50%) had received laser photocoagulation treatment before surgery. Fourteen (64%) of the study eyes achieved total retinal reattachment after initial vitrectomy, and 19 eyes (86%) were reattached completely at final examination. Thirteen eyes (59%) achieved a visual acuity of better than 0.1. Group I patients had a significantly higher rate of recurrent combined traction rhegmatogenous retinal detachment (P = 0.01) and a significantly worse final visual outcome (P = 0.01). CONCLUSIONS: Better surgical results are expected in eyes without NVD than with NVD among patients who undergo vitrectomy for TRD after BRVO. Although the authors were unable to determine the reason for this difference in the current study, they speculate that the degree of retinal nonperfusion, diffusible angiogenic factors, and distance of the site of occlusion from the disc may each affect visual and anatomic outcomes in these eyes.

Aged↗

The Reel Splint: experience with a new traction splint apparatus in the prehospital setting.

A new lower extremity splint apparatus was applied by paramedics to 50 patients in the prehospital setting to manage a total of 60 injuries. The Reel Splint was designed to provide stabilization with or without traction to a variety of angulated lower extremity fractures/dislocations. In 37 instances (74%), the splint was judged by the rescuers to be superior to the standard Thomas splint. In this series the splint was used successfully for extrication , to immobilize deformed limbs, and to provide traction for the restoration and maintenance of peripheral circulation, with frequent pain relief. No deleterious functional complexities or manufacturing defects were identified. The Reel Splint is a uniquely useful alternative to currently available splints.

Allied Health Personnel↗

Stability of the mandibular condylar process after functionally stable traction-screw-osteosynthesis (TSO) with a self-tapping screw-pin.

The behaviour under stress of the condylar processes of the mandible was examined as to possible physiological and pathological influence after traction screw osteosynthesis of experimental condylar neck and base fractures. Stresses were applied in a sagittal direction and laterally in a load device fitted with an electronic power recorder. The behaviour under stress was recorded in load-path diagrams. The interfragmentary compression which can be applied intuitively under operating conditions was measured with an electronically calibrated torque wrench and compared with the maximum resistance to tensile stress, i.e. the force necessary to rip the screw out of the proximal fragment. Compared with the strain on the joint resulting from masticatory pressure and the possible performance of the masticatory muscles traction-screw osteosynthesis of condylar neck and base fractures was seen to be functionally stable, but not mastication stable.

Bone Screws↗

Circumferential wrapping of a flap around a scarred peripheral nerve for salvage of end-stage traction neuritis.

Nine patients with chronic severe pain due to end-stage traction neuritis of an intact peripheral nerve underwent external neurolysis and epineurectomy or epineurectomy and internal neurolysis followed by circumferential wrapping of the involved segment of nerve with a pedicle flap or free flap consisting of either subcutaneous fat tissue, fascia, or muscle. Seven patients (77%) followed for between 1 and 5 years had substantial relief of pain. Two patients (22%) had no decrease in their pain at all. Circumferential wrapping may cushion the nerve from external pressure on the overlying skin, may isolate the nerve from the traction forces of adjacent moving tendons to allow improved gliding of the nerve, and may promote revascularization of a scarred nerve. This surgery may be indicated for patients with persistent pain following multiple carpal tunnel or cubital tunnel surgeries.

Adult↗

The TOTS (temporary outside traction suture): a new technique to allow easy suture placement and improve capsular shift in arthroscopic bankart repair.

We describe a new technique to allow easy placement of anterior sutures and to improve the proximal capsular shift in arthroscopic anterior stabilization of the shoulder, which we call the temporary outside traction suture (TOTS). Two standard portals are used: posterior and anterosuperior. Using a curved suture hook, both the capsule and the labrum are perforated at approximately the 5-o'clock position, and a monofilament suture is passed through the tissues. The suture is first retrieved through the anterior canula and then placed outside the canula. After labrum detachment and glenoid preparation, 1 or 2 further inferior sutures can be placed before the first suture is retrieved inside the canula and used. The technique of the TOTS has many advantages. (1) It allows easy placement of the first suture before the anterior capsule and labrum have been released. This makes this step much more difficult due to the lack of tension in the anterior tissues and anterior subluxation of the humeral head. (2) It allows the surgeon to choose, with accuracy, the amount of capsule taken, according to the severity of the capsular lesions and the degree of capsular laxity. It can also allow anatomic recreation of the anterior band of the inferior glenohumeral ligament (IGHL). (3) By placing tension on the suture, it avoids damaging the anterior capsule and labrum with the shaver and burr while preparing the scapula neck and can aid with haemostasis. (4) Tension on the suture also allows one to easily place 1 or 2 further sutures in a lower position. (5) It avoids entangling the sutures in the canula. (6) It allows one to perform a capsular shift of approximately 10 to 15 mm when the traction suture is retrieved and implanted with an anchor in the 3- or even 2-o'clock position.

Arthroscopy↗

Successful treatment of tractional corectopia using 2 mJ of energy with an Nd:YAG laser.

Although the Nd:YAG laser is most commonly used to perform posterior capsulotomies after cataract surgery, it has also been used to treat a variety of other anterior segment abnormalities including tractional corectopia, iridocorneal adhesions, persistent pupillary membranes, and posterior synechiae. Numerous reports on the use of the Nd:YAG laser to treat structures in the anterior segment have emphasized the need to use higher pulse energy for pupillary membranes, compared with the lower settings required for posterior capsulotomy. Steinert and Puliafito noted that single pulses of 4 to 12 mJ may be required to treat pupillary membranes "in a manner similar to that of a stonemason chipping at marble" in their description treating a membrane considerably thicker than what we describe. We report the successful treatment of tractional corectopia due to an anterior membrane strand in a child with only 2 mJ of total energy.

Eye Abnormalities↗

Vitrectomy for macular pucker and vitreomacular traction syndrome.

During the course of a so-called posterior vitreous detachment, a thin layer of the posterior vitreous cortex often remains adherent to the underlying retina. Tangential stretch of this vitreous pseudomembrane may cause vitreomacular traction syndrome, edema, and macular hole formation. The same process appears to underlie the development of true epimacular membranes (idiopathic macular pucker). Vitrectomy is generally agreed to be the most appropriate treatment for these clinical situations. We evaluated the incidence of vitreomacular adhesion and of visual improvement after vitrectomy of eyes with macular pucker (group 1; n=60) and vitreomacular traction syndrome (group 2; n=50). Vitreomacular attachment was assessed during vitrectomy under the condition of continuous air infusion. In the two groups, complete or partial vitreous attachment to the macula was observed in 57.4% and 74%, respectively. We conclude that vitreomacular adhesion is a common feature of the two clinical situations. Visual improvement was achieved in 73% of both groups. High rates of postoperative visual acuities of 20/50 or better (60.6% in group-1; 65.7% in group-2 cases) occurred only in eyes with preoperative values of 20/100 or better. It is reported that the visual outcome of vitreoretinal surgery for the two clinical conditions deteriorates with increasing duration after initial manifestation. Vitrectomy should not be postponed in patients who complain of disturbing visual symptoms such as reduced visual acuity, metamorphopsia and disturbance of binocular reading.

Adolescent↗

Effects of fibrovascular traction and pooling of tears on corneal topographic changes induced by pterygium.

AIM: To investigate the effects of fibrovascular traction and the pooling of tears at the pterygium apex on the corneal topographic changes induced by pterygium. METHODS: A total of 16 eyes of 14 cases with primary pterygium were included in the study. A computerized corneal topography system was used for corneal topography examinations. Baseline keratographs were taken two times at straight gaze. A repeat corneoscope photograph was immediately obtained in temporal gaze. Then the tears at the pterygium apex were dried with a cellulose sponge, and a new corneoscope photograph was immediately obtained without allowing one to blink. Corneal topographic maps (numeric maps) were divided into 301 fields in 24 meridians. One colour was allocated to each field, representing its mean refractive power for all groups. In all eyes, keratometric astigmatism at the 3 mm central cornea and total mean corneal refractive power were found. Data were compared using paired-samples two-tailed t-tests. RESULTS: Keratometric astigmatism at the 3 mm central cornea was significantly reduced at the temporal gaze (3.10+/-2.34 D, t=3.40, P=0.027) and dried eyes (2.12+/-1.01 D, t=4.74, P=0.001) according to the first baseline measurement (4.31+/-1.91 D) of the total mean corneal refractive power was found to be 43.45+/-1.28 D (39.29-45.87) at the first baseline measurement. There was no change at the temporal gaze (43.54+/-1.06 D, P>0.05). However, the total corneal refractive power was significantly higher in dried eyes (44.26+/-0.93 D, t=34.92, P<0.001). The steepest region of corneal topography was a superior quadrant, and the flattest area was a nasal quadrant at the baseline. At the temporal gaze, the cornea was significantly flatter in the superior and inferior sides of the pterygium meridian. After dried pooling of tears, topographic abnormalities returned, and the cornea became more uniform and symmetric. CONCLUSION: We conclude that the pooling of tears at the pterygium apex plays an important role, but fibrovascular traction has no effect on the corneal topographical changes induced by pterygium.

Adult↗

Intact myelinated fibres in biopsies of ventral spinal roots after preganglionic traction injury to the brachial plexus. A proof that Sherrington's 'wrong way afferents' exist in man?

Bell-Magendie's law of separation of spinal function states that afferent and efferent fibres join the spinal cord separately in ventral and dorsal spinal nerve roots. For over 100 years there have been reports that challenge the exclusiveness of this law in mammals; very few studies have referred to man. We conducted a prospective morphological study in patients with preganglionic traction injuries of the brachial plexus to address this question. Avulsed ventral and dorsal roots were examined after variable intervals from the injury for histological and ultrastructural evidence for myelinated afferent fibres entering the cord via the ventral roots. Intact myelinated fibres were found in all ventral root specimens, but the majority of fibres in later biopsies are regenerative. A small number of fibres could be demonstrated that are likely to be 'wrong way ventral afferents'. Their number is falsely low due to wallerian degeneration of dorsal and ventral afferents following the mechanical and ischaemic effects of traction injury. Our findings are the first morphological evidence in human material that Bell-Magendie's law might not entirely be correct and they underline the difficulties in comparing traumatic with experimental rhizotomy.

Adult↗

Modified cross-pin femoral fixation using long needles, polydioxanone suture, and traction suture for hamstring anterior cruciate ligament reconstruction.

The use of cross-pin femoral fixation in anterior cruciate ligament (ACL) reconstruction using semitendinosus and gracilis (ST/G) tendons has been shown to be biomechanically sound. As a result of some technical problems that we encountered, we modified the technique of the DePuy OrthoTech Xact ACL Graft Fixation System (DePuy, Warsaw, IN) using No. 2/0 polydioxanone suture (PDS) with long needles normally used for inside-out meniscal repair. In addition, a No. 5 Ethibond suture loop (Ethicon, Somerville, NJ) is used for traction of the ST/G graft up the femoral tunnel. Using a 2-suture loops technique, the traction suture loop offers a more effective in-line pull for the graft and it pulls the ST/G loops slightly higher than the alignment PDS. By so doing, it lessens the chance of kinking the alignment guidewire or even amputating the graft. Although not reported in literature, this type of graft complication is possible in other single-alignment suture or guidewire techniques.

Journal Article↗

Obstetric brachial plexus palsy: a large animal model for traction injury and its repair. Part 1: age of the recipient.

A Sunderland type IV traction injury to the C6 root of the sheep or lamb brachial plexus was used as a model for obstetric traction injury to the C5 root in humans. The injury was created and immediately repaired using interfascicular nerve autografts in a group of adult sheep and a group of newborn lambs. The animals were examined using electrophysiological and morphometric techniques 1 year after operation. It was found that the recovery of neuromuscular function was superior in the lambs. The implication is that nerves in newborn animals have a better potential for regeneration than that seen in older individuals. This is discussed with reference to the management of obstetric brachial plexus palsy.

Age Factors↗

Assessment of the method and timing of repair of a brachial plexus traction injury in an animal model for obstetric brachial plexus palsy.

A Sunderland type IV traction injury to the C6 root of adult sheep or newborn lamb brachial plexus was used as a model for obstetric traction injury to the C5 root in humans. In one experimental cohort the injury was created and repaired using interfascicular nerve autografts or coaxially aligned freeze-thawed skeletal muscle autografts in a group of adult sheep and in a group of newborn lambs. In a second cohort a similar injury was created and repaired either immediately or after a delay of 30 days, using either interfascicular nerve autografts or coaxially aligned freeze-thawed skeletal muscle autografts in four groups of six newborn lambs. In all cases both functional and morphometric indices of nerve regeneration were poorer in the injured and repaired nerves than in normal nerves. In lambs the method of repair made no difference and no significant differences were found for any of the indices of nerve function or morphology. In sheep the use of muscle grafts was associated with a poorer outcome than the use of nerve autografts. Where a delay of 30 days had elapsed between injury and repair, the results using nerve autografts were not significantly different. Where freeze-thawed muscle autografts had been used, the maturation of the regenerated nerve fibres after delay was significantly poorer than after immediate repair. The electrophysiological variables CV(max) and jitter, which may be applied clinically, were found to be good discriminators of recovery in all of the animals and in respect of all procedures.

Analysis of Variance↗

Retrograde degeneration of the facial nerve after acute traction on parotid gland: an experimental investigation.

The parotid gland of the cat underwent traction for 2 hours (group A) or until the facial nerve was broken (group B). The cats survived postoperatively for 1 day, 2 weeks, 1 month, and 3 months, respectively. Each cat underwent an electroneurography session before they were killed. The facial nerve was harvested and underwent histologic examination. The present study demonstrated that, in group A, the degree of facial nerve degeneration indicated with evoked electroneurography was 100% at 1 day and 2 weeks and 85% and 35%, respectively, at 1 and 3 months after damage. In group B, no electric response was recorded, epineurium of extratemporal segment was broken. This study also showed that the pronounced alteration of the facial nerve following acute traction on the parotid gland was retrograde degeneration; it involved up to its internal acoustic meatus segment. Furthermore, pronounced damage was noted in its stylomastoid foramen and extratemporal segment.

Animals↗

FRET measurements of cell-traction forces and nano-scale clustering of adhesion ligands varied by substrate stiffness.

The mechanical properties of cell adhesion substrates regulate cell phenotype, but the mechanism of this relation is currently unclear. It may involve the magnitude of traction force applied by the cell, and/or the ability of the cells to rearrange the cell adhesion molecules presented from the material. In this study, we describe a FRET technique that can be used to evaluate the mechanics of cell-material interactions at the molecular level and simultaneously quantify the cell-based nanoscale rearrangement of the material itself. We found that these events depended on the mechanical rigidity of the adhesion substrate. Furthermore, both the proliferation and differentiation of preosteoblasts (MC3T3-E1) correlated to the magnitude of force that cells generate to cluster the cell adhesion ligands, but not the extent of ligand clustering. Together, these data demonstrate the utility of FRET in analyzing cell-material interactions, and suggest that regulation of phenotype with substrate stiffness is related to alterations in cellular traction forces.

3T3 Cells↗