Double-loop Technique Research Articles

Comparison of imaging changes in pulmonary artery diameter at the occlusion site using silk or metal clamps for pulmonary artery troubles.

We analysed our clinical experience using silk sutures [the double-loop technique (DLT)] or DeBakey type vascular clamp (DeBakey clamp) for pulmonary artery (PA) troubles during anatomical lung resection to validate its practicality and safety. We retrospectively reviewed the records of patients who underwent either of the above clamping techniques during anatomical lung resection at our hospital between April 2007 and August 2022. We measured the PA diameter at the occlusion site on computed tomography images acquired within 1 year pre- and postoperatively. The difference between pre- and postoperative diameters of the occlusion sites was calculated as the change in the PA diameter. We zoned the occlusion site of the PA to adjust for variation. PA deformation was evaluated as an adverse event caused by clamping. Ultimately, 27 and 26 patients who underwent the DLT and DeBakey clamp, respectively, were included. No additional injury due to the clamp procedure was found in either group. For zone R1/L1, defined as the main PA, the median changes in the PA diameter were 0.02 (-0.7 to 0.27) mm for the DLT and 0.36 (-0.28 to 0.89) mm for the DeBakey clamp. No significant differences were observed between the 2 groups (P = 0.106). Furthermore, no aneurysms, dissections, or stenoses were found in either group. The DLT and DeBakey clamp had only minimal effects on the occlusion site of the PA. The DLT is a practical thoracoscopic technique for PA bleeding when primary haemostasis has been achieved.

Experimental and histological evaluation of each clamp technique for pulmonary artery.

The double-loop technique has been used in our clinical settings for pulmonary arterioplasty and/or injured artery repair during thoracoscopic anatomical lung resection. We evaluated the pressure resistance capacity and intimal load to determine the effectiveness and safety of the double-loop technique. The double-loop technique, DeBakey clamp, Fogarty clamp, endovascular clips, and vessel loop technique were evaluated. During an experimental study, a polyvinyl alcohol main pulmonary artery model, manometer, and in-deflation device were used to measure the burst pressure. The maximum clamp pressure was measured using a pressure-measuring film. Each measurement was performed 10 times. During the histological study, we measured the burst pressure and evaluated the intimal damage of the human pulmonary artery associated with the double-loop technique and DeBakey clamp. The experimental burst pressure (mmHg) and maximum clamp pressure (MPa) between the double-loop technique and DeBakey at the third notch were not significantly different (24.6 ± 2.8 and 21.8 ± 2.8, P = 0.094; 1.54 ± 0.12 and 1.49 ± 0.12, P = 0.954). During the histological study, the burst pressures of the double-loop technique and DeBakey at the third notch were also not significantly different (P = 0.754). Furthermore, the double-loop technique resulted in only intimal deformation in each five samples. The double-loop technique is feasible for thoracoscopic anatomical lung resection because it has similar pressure resistance capacity and intimal load as DeBakey at the third notch.

Clinical Results of Flexor Tendon Repair in Zone II Using a six Strand Double Loop Technique.

The purpose of this study is to report the clinical results after repair of flexor tendon zone II injuries utilizing a 6-strand double-loop technique and early post-operative active rehabilitation. We retrospectively reviewed 22 patients involving 51 cases with zone II flexor tendon repair using a six strand double loop technique from September 1996 to December 2012. Most common mechanism of injuries was sharp lacerations (86.5%). Tendon injuries occurred equally in manual and non-manual workers and were work-related in 33% of the cases. The Strickland score for active range of motion (ROM) postoperatively was excellent and good in the majority of the cases (81%). The rupture rate was 1.9%. The six strand double loop technique for Zone II flexor tendon repair leads to good and excellent motion in the majority of patients and low re- rupture rate. It is clinically effective and allows for early postoperative active rehabilitation.

Double loop technique for Percutaneous Transvenous Mitral Commissurotomy

Percutaneous Transvenous Mitral Commissurotomy (PTMC) is a standard treatment for critical mitral stenosis. In certain situations such as large left atrium (LA) or low trans-septal puncture, there is technical difficulty in crossing a PTMC balloon across the mitral valve, leading to high failure rate. I hereby describe a case of PTMC successfully performed by using double loop technique to cross the mitral valve.

Double-Loop Technique Using Titanium Molybdenum Alloy Wire for Fabrication of Nasal Stents in Nasoalveolar Molding Therapy for Cleft Lip and Palate Patients

This article presents a technique for fabricating a modified nasoalveolar molding appliance using 0.032-inch titanium-molybdenum alloy wire for nasal stents incorporating a double loop. The nasal stents are included in the acrylic molding plate at the time the appliance is inserted. The acrylic retention button used in a conventional appliance is replaced by a simple retention hook fabricated using titanium-molybdenum alloy wire. This technique is an effective alternative to a conventional appliance, and it simplifies the appliance-modification process during follow-up visits.

Double-loop Anatomic Acromioclavicular Reconstruction

Acromioclavicular (AC) reconstruction surgery is per- formed to address high-grade AC separations. In the double-loop anatomic reconstruction, the coracoclavicular ligaments are recon- structed in an anatomic fashion similar to the technique described by Mazzocca and colleagues using a free tissue graft and tunnels through the clavicle. However, the double-loop technique passes a graft both through and around the clavicle using semitendinosus graft. This allows maximal use of the long hamstring graft. A preliminary case series of 7 patients (7 operations) is presented. Shoulder complications were observed in 0 patients who underwent double-loop anatomic acromioclavicular reconstruction. Temporary hamstring graft harvest site pain observed in 2 patients. The described technique is safe and potentially useful alternative method for AC reconstruction.

Laparoscopic Roux-en-Y gastric bypass with hand-sewn gastrojejunostomy using an absorbable bidirectional monofilament barbed suture: Review of the literature and illustrative case video

The laparoscopic Roux-en-Y gastric bypass (LRYGB) is a technically demanding procedure. With the advent of the laparoscopic approach for RYGB, many techniques have evolved. There is no consensus on the optimal gastrojejunostomy anastomotic (GJA) technique. The hand-sewn technique with absorbable bidirectional monofilament barbed suture Stratafix (Ethicon Endosurgery, Inc., Cincinnati, OH, USA) appears to be ideal for GJA using a double loop technique.

Double-Loop Technique Using Titanium-Molybdenum Alloy Wire for Fabrication of Nasal Stents in Nasoalveolar Molding Therapy for Cleft Lip and Palate Patients.

This article presents a technique for the fabrication of a modified nasoalveolar molding appliance using 0.032-inch titanium-molybdenum alloy wire for nasal stents incorporating a "double loop." The nasal stents are included in the acrylic molding plate at the time of appliance insertion. The acrylic retention button used in a conventional appliance is replaced by a simple retention hook fabricated using titanium-molybdenum alloy wire. This technique can be used as an effective alternative to the conventional appliance, which also simplifies the appliance-modification process during follow-up visits.

Strategies for Repair of Radial Tears Close to the Meniscal Rim—Biomechanical Analysis with a Cyclic Loading Protocol

Background Lateral meniscectomy contributes to early-onset osteoarthritis. Biomechanical properties of sutures repairs for complete radial meniscal tears remain unknown. Hypothesis Double horizontal suture techniques for repair of radial meniscal tears with a shorter distance from the meniscal rim provide significantly higher structural properties than do comparable single-suture techniques with a wider distance from the meniscal rim. Study Design Controlled laboratory study. Methods In 55 fresh-frozen porcine menisci, standardized complete radial meniscal tears were repaired with different distances from the meniscal rim and tear edges and with different numbers of sutures. In group A, the suture was 4 mm from the tear and 8 mm from the meniscal rim; group B, 2 mm from tear; group C, 2 mm from tear, 12 mm from rim; group D, double-loop technique, 2 mm from tear, 5 mm and 10 mm from rim; group E, longitudinal tear sutured with 1 loop, 8 mm from rim, and 4 mm between stitches. The specimens were cyclically loaded 1000 times between 5 and 20 N and loaded to failure. Results All repaired constructs survived the cyclic loading protocol. Compared with the single-loop techniques, the double-loop technique (group D) showed a significantly higher maximum load and yield load and significantly lower displacement after 1000 cycles. Compared with group B, group C had a higher displacement after 1000 cycles (P < .05), and its stiffness showed a descriptive negative trend (P = .09). Displacement after cycling testing in group C was higher than in groups B and D (P < .05). Conclusion Repair of radial meniscal tears with a second suture and shorter distance from the meniscal rim has a positive influence on primary stability. Different distances from tear edges apparently have no influence on structural properties. Clinical Relevance Horizontal sutures for repair of radial meniscal tears provide high stability and can be enhanced with a second horizontal suture and shorter distance from the meniscal rim.

Clinical Results of Flexor Tendon Repair in Zone II Using a Six-Strand Double-Loop Technique Compared with a Two-Strand Technique

The clinical and functional results of 46 patients who underwent zone II flexor tendon repair using the Lim/Tsai technique combined with the Kleinert/Duran early active mobilisation regime and place and hold exercises were assessed. The results were compared with 25 patients who were treated by the modified Kessler technique and the Kleinert/Duran regime alone. After a follow-up of 8 to 17 weeks, the Lim/Tsai group had a better grip strength and a significantly better total active motion of 141 degrees compared with 123 degrees . The rupture rates (Lim/Tsai: 1/51; Kessler: 3/26) and the extension deficits were not statistically different in the two groups. However, the complication rate was significantly lower and the average time of treatment was significantly shorter in the Lim/Tsai group. These results support the use of the Lim/Tsai six-strand repair technique in zone II flexor tendon injuries and early active mobilisation without rubber-band traction.

In vitro biomechanical study to compare the double-loop technique with the Pulvertaft weave for tendon anastomosis

The tensile strength of a double-loop technique for tendon anastomosis was compared with those of two modified Kessler techniques and the traditional Pulvertaft weave technique. The experiments were made on specimens of fresh human extensor tendon. The double-loop technique was significantly stronger than the other suture techniques.

A Biomechanical Comparison of Four Extensor Tendon Repair Techniques in Zone IV

This study was designed to evaluate the biomechanical parameters of four different suture techniques specifically designed for zone IV extensor tendon injuries: the double figure of eight, the double modified Kessler, the six-strand double-loop, and the modified Becker suturing techniques. Ease of repair, tendon shortening, strength to 1-mm gap, strength to 2-mm gap, ultimate strength, and mode of repair failure were evaluated. Twelve fresh-frozen cadaver hand-forearm units (48 fingers) were randomly assigned to the four suture repair treatments. The speed of tendon repair as performed by two matched-hand surgeons was recorded. Prerepair and postrepair tendon lengths were measured to document tendon shortening. The repair was stressed by linear distraction at 2.0 mm/minute using a servohydraulic frame. Video recordings of each distraction were independently reviewed for biomechanical parameters by three physician-observers in a double-blind setup. A one-way analysis of variance and t test analysis was performed. Results show that the double figure-of-eight technique and the double modified Kessler were significantly (p < 0.05) easier to perform at 7 minutes 31 seconds and 7 minutes 58 seconds, respectively, than the other two techniques. Tendon shortening ranged from 1.9 to 2.4 mm. There was no statistically significant difference in tendon shortening among the four techniques. Strength to 1-mm gap was significantly higher with the modified Becker technique, with a mean 28.8 +/- 8.0 N. This was followed by the six-strand double-loop technique, with 21.0 +/- 6.6 N, the double modified Kessler at 17.7 +/- 4.5 N, and the figure-of-eight technique at 17.5 +/- 2.4 N. Strength to 2-mm gap was significantly (p < 0.05) greater for the modified Becker technique and the modified Kessler technique at 56.0 +/- 9.2 N and 48.6 +/- 12.6 N, respectively, as compared with the other two suture methods. The modified Becker technique showed the highest ultimate strength at maximal loading at 63.3 +/- 7.8 N, followed by the double modified Kessler technique with strength of 56.8 +/- 14.8 N. Both were significantly stronger than the other two techniques. This study shows that the modified Becker suture technique, although not easily performed, proved to be the strongest repair, with a significantly greater resistance to 1-mm and 2-mm gap and the greatest ultimate strength on maximal loading.

In vitro biomechanical evaluation of the double loop suture for flexor tendon repair.

Fifty-one fresh frozen human anatomic specimen flexor superficialis and profundus tendons that had been transected completely were repaired using the double loop, the single loop, and the modified Kessler techniques, and the resistances to mechanical distraction at 1, 2, and 3 mm and the ultimate load to failure were compared. The mechanical distraction at 1, 2, and 3 mm created nearly identical gaps at the tendon repair sites. There was no significant difference among the three repair techniques to resisting distraction at 1 and 2 mm. However, the double loop technique presented a mean resistance force of 22.0 N to distraction at 3 mm and 45.8 N in load to failure, which was significantly greater than the single loop (18.8 N at 3 mm distraction and 31.5 N failure load) and the modified Kessler (19.0 N at 3 mm distraction and 26.0 N failure load). This suggests the double loop technique may be superior to the single loop and the modified Kessler techniques in resisting gap in the range of forces generated in the early rehabilitation protocol.

Measuring stability of wire cerclage in femoral fractures when performing total hip replacement. In vitro study on a standardized bone model.

The stability of wire cerclage was investigated on a wooden model. Two semitubular shells made of hard oak were firmly joined together using cerclage wires of different diameters and with different techniques. A conical test piece was then implanted. The test set-up was subjected once to an axial force of 4 kN and a torque of 20 Nm using a testing machine. Implant excursion at the interface was measured. One hundred forty measurements carried out on test pieces with fissures demonstrated that cerclage wires with the largest diameter possible should be used with a double-loop technique. Wire diameters under 1.2 mm are unsuitable for cerclage of the femur because they rupture easily. The most stable cerclage is obtained with two double cerclages using 1.5-mm stainless steel wires. Although micromotion is greater than for the reference group without fissures, no cases of excursions exceeding 100 microns could be measured. In comparison with a femoral shaft that is not fractured, marked instability remains. It is recommended that a tightening tool be used to tighten the wires, as this achieves considerably more stable cerclage than that achieved with two forceps.

Polarization Behavior of Austenitic and Duplex Stainless Steels in the Double Loop Reactivation Test

Abstract The corrosion behavior of AISI 304L and 308L stainless steels (SSs) in electro-potentiostatic reactivation (EPR) tests has been investigated using the double loop technique. The AISI 304L SS was tested in the fully austenitic and in the duplex (γ + δ) condition; the AISI 308L SS was in the form of a submerged arc weld metal having a duplex microstructure. The materials were aged at 700 C to induce phase transformation and sensitization and EPR tests were conducted both before and after the aging treatments. In tests on unaged material, single peaks in the corrosion current were detected in both the activation and reactivation potential scans (Ia and Ir respectively), and in the aged austenitic AISI 304L SS, the effects of sensitization were manifested, as expected, by an increase in both Ir and the ratio Ir to Ia. In tests on aged duplex materials, the increase in the height of the previously identified reactivation peak was accompanied by the appearance of a second reactivation peak, which coinc...

An Electrochemical Test for Detecting the Intergranular Corrosion Susceptibility of a Duplex Stainless Steel

Abstract The double-loop electrochemical potentiokinetic reactivation (EPR) method was used to evaluate the intergranular corrosion (IGC) susceptibility of a duplex stainless steel (SS). The purpose of the examination was to assess the influence of simulated weld cooling rates on microstructure and the subsequent IGC susceptibility. Those specimens that were rapidly cooled through a 1200 to 815 C (2200 to 1500 F) temperature range were found to exhibit the highest degree of susceptibility to intergranular attack (IGA) relative to those cooled more slowly through this region. Specimens cooled more slowly exhibited various degrees of improvement in the resistance to susceptibility. A good correlation was obtained between a modified oxalic acid test, similar to that described by ASTM Practice A262-A, and the electrochemical double-loop technique. The use of both of these procedures for IGC susceptibility examination is well documented for the case of 300 Series SS, but heretofore has not been described for t...