Single Stitch Research Articles

Hardware-Based Volumetric Knit-Wear

We present a hardware-based, volumetric approach for rendering knit wear at very interactive rates. A single stitch is represented by a volumetric texture with each voxel storing the main direction of the strands of yarn inside it. We render the knit wear in layers using an approximation of the Banks model. Our hardware implementation allows specular and diffuse material properties to change from one voxel to the next. This enables us to represent yarn made up of different components or render garments with complicated color patterns. Furthermore, our approach can handle self-shadowing of the stitches, and can easily be adapted to also include view-independent scattering. The resulting shader lends itself naturally to mip-mapping, and requires no reordering of the base geometry, making it versatile and easy to use. Categories and Subject Descriptors (according to ACM CCS): I.3.3 [Computer Graphics]: Hardware Applications Volumetric Textures

Epiglottopexy for the treatment of severe laryngomalacia.

Laryngomalacia is the most common cause of stridor in newborns and infants. Up until now, different surgical techniques for the treatment of this disease have been described. We report on a modified technique, the so called epiglottopexy, which is a laser-surgical treatment strategy in severe laryngomalacia. A total number of six children (ages: 6 weeks-10.4 years) were treated for life-threatening stridor, which was due to an isolated posterior displacement of the epiglottis during inspiration. In two patients, shortened aryepiglottic folds contributed to the stridor. In all of the children, a modified technique of epiglottopexy was performed transorally; in two cases, this was followed by laser surgical transection of the aryepiglottic folds. Epiglottopexy on the base of the tongue was performed using single suture stitches following laser-surgical vaporization of the corresponding mucosal areas of the epiglottis and the base of the tongue. No intra- or postoperative complications were observed. All six children demonstrated significant airway improvement without any further stridor. Deglutation was not impaired. The presented laser-surgical technique seems to be an appropriate therapy for treatment of severe forms of laryngomalacia characterized by an isolated posterior displacement of the epiglottis during inspiration.

Correction of traumatic tricuspid regurgitation using the double orifice technique

We present a case of acute traumatic tricuspid regurgitation in a 39-year-old man who was involved in a motor vehicle accident. A large ecchymotic region over the anterior chest wall prompted evaluation by both transthoracic and transesophageal echocardiography which confirmed the valvular injury. At surgery, valvular incompetence was found to be the result of a flail anterior leaflet due to papillary muscle rupture. The valve was successfully repaired using a single stitch double orifice technique in combination with a ring annuloplasty. The valve remains competent 18 months after surgery.

A novel approach to hysterotomy using a verres needle with an innerdyne sheath: an unusual presentation of molar pregnancy requiring hysterotomy.

Objective: To describe a novel approach to hysterotomy in management of a molar pregnancy in a patient with a large cervical fibroid. The fibroid, measuring 18 × 14 × 12 cm had stretched and attenuated the cervical canal, rendering a transcervical approach an unsafe option. Design: Case Report. Materials/Methods: A 28 year old primigravida presented at 8 weeks gestation with a non viable intrauterine pregnancy suspicious for a hydatidiform mole, a serum β hCG level of 100,000 mIU/ml and status post failed methotrexate treatment. The patient had a large cervical fibroid measuring 18 × 14 × 12 cm that had elongated and attenuated the cervical canal, precluding transcervical evacuation. A minilaparotomy and hysterotomy was performed for evacuation of products of conception. Under intraoperative transuterine ultrasound guidance, a verres needle with an innerdyne sheath was introduced through the uterine fundus into the uterine cavity. The innerdyne sheath was expanded to accommodate a 10 mm laparoscopic trocar sheath. An 8 mm flexible suction curette was introduced through the trocar sheath and the uterine contents were evacuated by suction curettage. Results: Complete evacuation of the uterine cavity was confirmed on intraoperative transuterine ultrasound. There was minimal bleeding during the procedure and virtually no spillage of uterine contents. Following removal of the trocar sheath, the resulting myometrial defect was less than 1 cm and closed with a single stitch of 0 chromic catgut. Conclusions: Utilization of the verees needle with the innerdyne sheath for hysterotomy provided an atraumatic entry with separation of myofibers rather than transection as seen with classic hysterotomy, minimizing the possibility of dehiscence in a subsequent pregnancy. A complete mole was confirmed on histopathology of products. The postoperative course was significant for a rapid decline in serum β HCG levels to normalization within 4 weeks post evacuation.

Oriental Double Eyelid: A Limited-Incision Technique

Although there are many procedures reported in the literature regarding the double-eyelid operation, they can be categorized basically into two groups: nonincision and incision. Conventionally, the nonincision technique has been shown to produce little postoperative edema. However, the probability of the fold disappearing is high, and this technique cannot be performed in patients with fatty eyelids. Conversely, the incision technique has contrary characteristics. As an alternative option, the author developed a limited-incision single-stitch technique that minimizes tissue injury and provides adequate adhesion for fold formation. With this method, a small single incision (3-4 mm) is made in the upper eyelid. Through the incision, the orbital fat can be removed, when indicated. Under direct vision, a levator aponeurosis or tarsus is attached to the muscle and the dermis of the pretarsal margin by a single stitch. This technique gives a durable, natural fold; has a short recovery time; and can be applied to patients with fatty eyelids. This method has the merits of both the incision and the nonincision techniques, and avoids the disadvantages of both procedures.

THE OPEN FINGER TECHNIQUE FOR THE RELEASE OF SYNDACTYLY

A new technique of syndactyly release is described. The technique differs from the standard methods in that more digital flaps are used, and these are longer and are not defatted. A single stitch is applied to secure the tip of the flap and the defects between the flaps are not closed or grafted, hence the term “open” technique. Eight patients had 12 webs released using this operation. We compare this technique with 12 patients who had a total of 19 webs released using the standard technique. Patients were assessed for six parameters of operative success.

Perilimbal topical anesthesia for clear corneal phacoemulsification

Purpose To evaluate the efficacy of perilimbal topical anesthesia for clear corneal cataract surgery. Setting Department of Ophthalmology, University of Udine, Udine, Italy. Methods Seventy-five consecutive patients were studied for perioperative pain, visual outcome, and intraoperative complications. Topical anesthesia was administered with a cellulose sponge soaked in preservative-free lidocaine 2%. The perilimbal area was touched 360 degrees for 30 seconds with the sponge tip under the operating microscope just before surgery. No sedation or adjunctive anesthetic drops were given. Surgery was performed through a temporal corneal tunnel with the easy-chop technique. Pain was scored on a subjective scale from 0 (no pain) to 3 (severe pain). Visual acuity was measured 1 day and 1 week after surgery. Mean operating time was recorded. Results Sixty-nine patients (92%) tolerated the procedure well, giving a pain score of 0 or 1. Six (8%) of the 40 patients who had a single stitch at the end of surgery scored 2. No patient reported pain during iris touch, intraocular lens implantation, or conjunctiva manipulation. No intraoperative complications were recorded. Mean operating time was 12.7 minutes ± 3.7 (SD) (range 7 to 34 minutes). Mean preoperative visual acuity was 0.4 ± 0.2 (range 0.01 to 0.80). Visual acuity of 0.5 or better was attained in 93.6% of eyes 1 day and in 96% 1 week postoperatively. Conclusion Perilimbal topical anesthesia was an effective and easy-to-administer anesthetic procedure for phacoemulsification, providing good perioperative pain tolerance by patients and rapid visual recovery.

Meniscal repair devices

Summary: Meniscal repair devices not requiring accessory incisions are attractive. Many factors contribute to their clinical effectiveness including their biomechanical characteristics. This study compared several new meniscal repair devices with standard meniscal suture techniques. Using a porcine model, axis-of-insertion loads were applied to various meniscal sutures and repair devices. A single device or stitch was placed in a created meniscal tear and a load applied. Both loads and modes of failure were recorded. The load-to-failure data show stratification into 4 distinct statistical groups. Group A, 113 N for a double vertical stitch; group B, 80 N for a single vertical stitch; group C, 57 N for the BioStinger, 56 N for a horizontal mattress stitch, and 50 N for the T-Fix stitch; and group D, 33 N for the Meniscus Arrow (inserted by hand or gun), 32 N for the Clearfix screw, 31 N for the SDsorb staple, 30 N for the Mitek meniscal repair system, and 27 N for the Biomet staple. The failure mechanism varied. Sutures broke away from the knot. The Meniscus Arrow and BioStinger pulled through the inner rim with the crossbar intact. The Clearfix screw failed by multiple mechanisms, whereas 1 leg of the SDsorb staple always pulled out of the outer rim. The Mitek device usually failed by pullout from the inner rim. The Biomet staple always broke at the crosshead or just below it. Although the surgeon should be aware of the material properties of the repair technique chosen for a meniscal repair, this information is only an indication of device performance and may not correlate with clinical healing results.Arthroscopy: The Journal of Arthroscopic and Related surgery, Vol 16, No 6 (September), 2000: pp 613–618

縫合したＣＦＲＰ積層板のモードＩ層間破壊靭性の向上に関する研究

The double cantilever beam (DCB) tests were executed for stitched CFRP laminates to evaluate the interlaminar fracture toughness (GIC). The stitch parameters (stitch line spacing and pitch spacing) were changed and their effects on interlaminar fracture toughness were examined by means of DCB tests and FEM analysis. Different shape patterns in load-crack opening displacement (COD) curves were obtained at one level of equivalent stitch density for several specimens. It can be concluded that the difference in load-COD curve shape was affected by the stitch parameters. On the other hand, GICvalues themselves were not so seriously affected by the shape of load-COD curves. Interlaminar fracture toughness is mainly governed by the stitch density, in other words, increase in stitch density in laminates leads to the improvement in GICt. Simple FEM model tuned for unstitched and single stitch line DCB specimens was presented. FEM analysis results in linear relationship the between interlaminar fracture toughness of stitched CFRP laminates and the stitch density. Moreover, GICA of CFRP laminates with arbitrary stitched parameter can be predicted by the simple FEM model.

Chain removal of myomata by colpotomy

Multiple myomectomy was performed in 67 women between June 1996 and July 1998. In almost every case, myomas were sutured one to another with a single stitch of 1 silk, forming a chain, and taken out through the vaginal cul-de-sac. We believe this method reduces the risk of losing myomas inside the peritoneal cavity and shortens operating time.

Endoscopic suturing

Suturing at flexible endoscopy might extend the range of less invasive surgical procedures that can be performed without incision. The development of sewing machines that can place single and multiple stitches in the gastrointestinal tract is outlined. Methods of tying knots and cutting thread at flexible endoscopy have also been developed. The results of some applications, including the treatment of gastro-oesophageal reflux disease, the closure of perforations, haemostasis, and the attachment of feeding tubes and radiotelemetry capsules to tissue using endoscopic suturing, are described.

An On-Line Monitoring System to Recognize Stitch Defects Through Thread Motion and High Speed Image Analyses

A sensor system that inspects a garment as it is being sewn has the potential to eliminate much of the cost associated with inspection and to improve product quality. An economically feasible on-line stitch quality monitoring system is under development that utilizes commercially-available, low-cost piezoelectric sensors and a PC-based Linux data acquisition system. The sensors respond to the vibration caused by the thread motion and output a corresponding waveform used to study and model the formation of single stitches. As a result, the presence of periodic occurrences can be identified and attributed to proper stitch formation. Conversely, the absence of such events can be utilized to signal the presence of single stitch defects and diagnose their causes. Finally, high speed image analysis of the sewing threads has verified conclusions drawn from the output signals of the piezoelectric sensors and contributed to a better understanding of the dynamics involved in high speed sewing.

Tricuspid Valve Repair for Functional Tricuspid Regurgitation

Tricuspid valve insufficiency can be caused by organic disease of the tricuspid valve (rheumatic disease, endocarditis, carcinoid, and so on); however, most tricuspid regurgitation encountered in clinical practice occurs in patients with chronic left-sided valvular lesions. Ten percent to 50% of patients with severe mitral valve dysfunction have significant tricuspid regurgitation. '3' In this situation, functional tricuspid regurgitation is attributable to pulmonary hypertension and right ventricular dilatati~n.~ Other factors that contribute to functional tricuspid insufficiency may include right ventricular-tricuspid valve disproportion with compromised function of the tricuspid valve apparatus' and depressed tricuspid annular shortening during systole. It is now generally accepted that moderate to severe functional tricuspid insufficiency should be addressed at the time of correction of left-sided valvular disease.6-8 Several surgical options have been used to treat functional tricuspid insufficiency. These include tricuspid valve replacement, bicuspidalization annuloplasty, DeVega suture annuloplasty, and ring annuloplasty (Carpentier [Baxter Healthcare, Irvine, CAI or Duran [Medtronic, Minneapolis, MN]). The first two options, tricuspid valve replacement and bicuspidalization annuloplasty, provide inferior results and should not be used in the setting of functional tricuspid regurgitation. Both the DeVega annuloplasty and the Carpentier ring annuloplasty provide excellent treatment of functional tricuspid reg~rgitation.~> ~-~ However, studies suggest that repair durability is better with the Carpentier annuloplasty, particularly in the setting of severe pulmonary hypertension.6*8 Other potential disadvantages of the DeVega annuloplasty include the possibility of complete repair dehiscence from the disruption of a single stitch and obligate semicircular deformation of the tricuspid annulus, which may impair long-term valvular function.6 Drawbacks to the Carpentier ring annuloplasty include increased cost, the introduction of foreign material with the attendant risk of endocarditis, and relative rigidity of the prosthesis, which fixes the annulus in the shape of the ring. Recent advances in understanding the physiology of the tricuspid valve have provided the rationale for the use of a new annuloplasty system to correct functional tricuspid ins~fficiency.~ Computer-based analysis of echocardiographic images of the tricuspid valve shows that the tricuspid annulus is a saddle-shaped structure that has sphincter action, being smaller in systole than in diastole. Anatomic studies show that five sixths of annular dilatation takes place at the base of the anterior and posterior leaflets.6 This understanding of the normal physiology and pathoanatomy of the tricuspid valve led us to use an annuloplasty system that is universally flexible and produces a measured plication of the annulus at the base of the anterior and posterior leaflets. Repair of the tricuspid valve using the flexible Cosgrove-Edwards Annuloplasty System (Baxter Healthcare, Irvine, CA) is described.

Two-, four-, and six-strand zone II flexor tendon repairs: An in situ biomechanical comparison using a cadaver model

A dynamic in vitro model of zone II flexor tendon repair was used to compare gliding resistance, gap formation, and ultimate strength of the 2-, 4-, and 6-strand repair techniques. Each of 12 hands was mounted to a loading frame with 3 flexor tendons attached to individual pneumatic cylinders. A spring attached to a pin through the distal end of each digit provided a 1.25-kg resistance force. The force required to flex each proximal interphalangeal joint to 90 degrees was determined. Following this, the tendons were sectioned and each was repaired using a different technique so that each specimen acted as its own control. The 2- and 4-strand core sutures were placed using a suture interlock technique with radial and ulnar grasping purchase of the tendon on each side of the transverse part of the repair. Each repair was accomplished using a single core stitch with the knot buried between the tendon ends. The 4-strand repair involved an additional horizontal mattress suture with the knot buried. Repair of the dorsal side of the tendon was performed followed by core suture placement. The palmar portion of the peripheral locking suture was completed after core suture placement. Following repair, each hand was remounted on the frame and cycled 1,000 times. After cyclic loading, the resulting gap between the repaired ends of each tendon was measured, the tendons were removed from the hand, and each was loaded to failure in tension. All tendon repairs showed a small, but not statistically significant, increase in gliding resistance after reconstruction. The 2-strand repair had significantly greater gap formation after cyclic loading (mean gap, 2.75 mm) than either the 4-strand (0.30 mm) or 6-strand (0.31 mm) repair. The tensile strength of the 6-strand repair (mean, 78.7 N) was significantly greater than either the 4-strand (means, 43.0 N) or 2-strand (mean, 33.9 N) repair.

A relatively atraumatic method of retrieving retracted digital flexor tendons

A relatively atraumatic, simple and very reliable method of retrieving the proximal end of a severed flexor tendon of a finger or thumb is described. The technique involves passing a Silastic feeding tube into the flexor tendon sheath, placing the retracted tendon within its lumen, and securing it in place with a single stitch. The feeding tube is then withdrawn until the tendon presents within the distal wound. Hypodermic needle fixation and tendon repair is then carried out in the usual manner.

Evaluation of Thermal Stresses at the Interface of a Stitch in a Stitched Laminate

The stresses in the vicinity of a single stitch through the thickness of an infinite cylindrical cross-ply laminate subjected to a unit temperature decrease are computed. Interest centers on the potential for microcracking in the vicinity of the through-thickness reinforcement. The infinite cylindrical cross-ply model is a simplification which leads to a tractible axisymmetric formulation, but which retains many of the three-dimensional features of the problem. In the model the stitch is a through-thickness cylinder consisting of fibers and resin, and the laminate consists of plys with fibers oriented radially and plys with fibers oriented circumferentially. Here only a [O/90]2s laminate is examined. Both glass and Kevlar stitches are considered, as is the possibility of resin pockets forming near the stitch. The results indicate that the presence of a resin pocket can alter the stress state in the vicinity of the stitch. In particular, the sign of a peak in the radial stress that occurs at the outside of the laminate changes from compression to tension when resin pockets are considered. The normal stresses in the resin pocket are all positive and their values are larger in the case of Kevlar stitch than in the case of glass stitch. This implies that the Kevlar stitched laminate is more likely to produce microcracking due to high residual stress after curing than the glass stitched laminate.

A high-stability, one-stitch W incision for cataract surgery

We describe a technique to create a highly stable, one-stitch W incision for use with rigid posterior chamber intraocular lenses (IOLs). Inverse U and W incisions are compared in 203 consecutive eyes with 3 months follow-up. A scleral groove resembling an inverted W is dissected away from the limbus, and the anterior chamber is entered by a conventional tunnel technique that resembles a frown incision but has an additional triangular, central scleral flap. When the incision is closed, a single stitch is placed through the flap, away from the limbus. Advantages of the W incision include reduction and control of astigmatism, improved self-sealing, reduced postoperative leakage, no special suture-material requirements, high mechanical stability, easy extendability for extracapsular cataract extraction or trabeculectomy, and intraoperative sealing of a leaking irrigation/aspiration opening by inverting the flap. The W incision offers high stability and multiple advantages over the frown incision and is suitable for use with rigid posterior chamber IOLs.

Transanaler rektaler Verschiebelappen (rectal advancement flap) versus mukosaflap mit internusnaht im management komplizierter fisteln des anorektums Eine prospektive klinische und manometrische studie

A prospective study was carried out on 55 patients with complicated anal fistulas (41 transsphincteric, 5 suprasphincteric and 9 rectovaginal) to evaluate the value of two sphincter-conserving techniques with primary occlusion of the internal ostium and endorectal advancement flap (group A, n = 34) or mucosal flap (group B, n = 21). Ten of the patients had Crohn's disease. Both techniques consist in one-stage fistulectomy without drainage of the intersphincteric space. The inflamed proctodeal and granulation tissue was carefully cleared. The site of the former primary orifice of the fistula was adapted by means of two or three peranally performed single stitches. The peranally applied suture included the layers of the internal anal sphincter muscle only. A mobilized flap of rectal wall (group A) and rectal mucosa and submucosa (group B) about 4 cm x 3 cm in size was stitched below the muscular sphincter. The perianal part of the wound was left to heal by second intention. Postoperatively there were 16 cases of suture leakage (23.5% in group A, and 38% in group B), and 19 patients (26% or 47% in both groups) had to have revision surgery because of recurrent fistula or sutur leakage; 2 patients (3.6%) developed incontinence with intermittent fecal soiling. Complete incontinence was not observed in any patient. No significant difference in clinical and functional results was determined between the two groups.

No Stitch Compared to Single Stitch Closure after Phacoemulsification

OBJECTIVE: Evaluation of the clinical outcome, especially surgically induced astigmatism, after 5.2 mm scleral tunnel incision, phacoemulsification and posterior chamber lens implantation, comparing one horizontal suture and no stitch closure. STUDY DESIGN AND PATIENTS: 40 patients admitted for cataract surgery were enrolled in the study. A single stitch was used to close the wound in the first 20 eyes, while in the latter 20 cases no stitch was placed. The patients were examined before surgery and one day, one week, two and eight months postoperatively. MAIN OUTCOME MEASURES: Keratometric astigmatism, postoperative visual acuity and intraocular pressure. RESULTS: No statistically significant differences in surgically induced astigmatism were found between the two groups. There were no complications in the no stitch group but a few suture related ones in the single stitch group. CONCLUSION: The induced keratometric astigmatism after phacoemulsification using a 5.2 mm incision is the same whether a horizontal suture or no suture is used. Suturing seems to be unnecessary, provided that a self-sealing incision is created.

Mode I delamination toughness of laminated composites with through-thickness reinforcement

Through-thickness reinforcement is an effective way to suppress delamination in laminated composites. Micromechanics based models are developed to study the effect of through-thickness reinforcement (stitching) in improving the Mode I delamination crack growth resistance of laminated composites. In the development of these models, two types of stitch geometries are considered. In the first case, the stitches are assumed disconnected as in many cases the top and the bottom surfaces of the stitched laminates are ground off to remove surface in-plane waviness caused by stitching loops. The force in the stitches in this case is estimated from frictional bonding between stitches and the matrix. In the second case, interconnected stitches are considered and the force carried by the stitches is modelled as Winkler elastic foundation type of stress-separation relation. The effect of stitches is expressed in terms of a single stitching parameter Gl or Gb and closed form analytical expressions for the crack-growth resistance (KR (Δa)) are obtained. The effects of the stitching parameter and various geometric and material properties are examined.