Suture Placement Research Articles

Fast absorbing gut sutures in dermatologic surgery: a systematic review and meta-analysis.

Fast gut cutaneous sutures have become more prominent due to their low tissue reactivity, rapid absorption, and elimination of suture removal visits. It is not known how fast gut sutures compare to other closure modalities. A comprehensive literature review was conducted to identify randomized controlled trials comparing fast gut sutures to alternative closure methods during dermatologic surgery. Data collected included patient and physician assessed cosmetic outcome as well as standardized complication rates. Six studies were included in final analysis and reported on 208 patients. Fast gut sutures were associated with lower physician opinions of final scar when compared to polypropylene sutures (SMD 0.438; 95% CI 0.082 to 0.794). No differences existed between physician opinion of fast gut sutures and cyanoacrylate tissue adhesive (SMD -0.024; 95% CI -0.605 to 0.556). Complications with fast gut suture placement were rare, and included infection, dehiscence, and hematomas. Fast gut sutures were less likely to experience wound dehiscence than tissue adhesive (p = 0.01). If no contraindications to polypropylene sutures exist, they may provide superior cosmetic outcomes compared to fast gut sutures. Further research is required to better quantify cosmetic outcomes and optimal use of fast gut sutures.

Approach to Severe Mitral Annular Calcification Using Ultrasonic Aspiration

Severe mitral annular calcification (MAC) is perhaps the greatest challenge faced in mitral valve surgery. Valve replacement in the setting of severe MAC carries with it the risk of numerous surgical complications and modes of technical failure, including catastrophic atrioventricular (AV) groove disruption. In the face of these challenges, a variety of surgical approaches to severe MAC have been described but without clear consensus. We describe an approach using the Cavitron Ultrasonic Surgical Aspirator (CUSA) emphasizing minimal, focal disruption of annular calcium. Ultrasonic aspiration is applied only when needed and only at the precise site of valve suture placement to aspirate away or merely soften dense calcium such that sutures can be placed through or around the calcified annulus. Our approach is simple and eliminates the need for complete annular decalcification which risks avoidable AV groove destabilization and requires complex annular reconstruction. In our experience of 55 cases of high-risk mitral replacement in the setting of very severe MAC, we report two cases of AV groove disruption (4%), two cases of coronary injury (4%), and two cases of stroke (4%), with no cases of paravalvular leak worse than mild. In-hospital mortality was 16%, due largely to significant underlying cardiac and non-cardiac comorbidity and underscoring the often underestimated non-technical risks inherent in these cases. While no single approach may be optimal in every case of severe MAC, we feel our technique of limited ultrasonic aspiration is an important tool in the mitral surgeon's armamentarium.

Navigating the landscape of periodontal and peri-implant microsurgery: A contemporary review

Periodontal and per-implant microsurgery have revolutionized the field of dental surgery, enabling precise and minimally invasive procedures with improved outcomes. The advent of microsurgical instruments, enhanced magnification systems, and specialized suturing techniques has allowed clinicians to achieve superior aesthetic and functional results while minimizing patient discomfort and morbidity. Furthermore, emerging technologies such as digital planning and guided surgery have complemented microsurgical techniques, enabling more predictable outcomes and patient-centered treatment approaches. The review aims to discuss the principles of microsurgery, including flap design, tissue handling, and suture placement, and explores their applications in the management of mucogingival defects and periimplantitis. Continued research and clinical advancements in this field are essential to further enhance treatment outcomes and refine surgical protocols for the benefit of patients and practitioners.

Thoracoscopic external traction suture elongation for the management of long-gap oesophageal atresia: a two-centre experience.

Van der Zee (VdZ) described a technique to elongate the oesophagus in long-gap oesophageal atresia (LGOA) by thoracoscopic placement of external traction sutures (TPETS). Here, we describe our experience of using this technique. Retrospective review of all LGOA + / - distal tracheo-oesophageal fistula (dTOF) cases where TPETS was used in our institutions. Data are given as medians (IQR). From 01/05/2019 to 01/03/2023, ten LGOA patients were treated by the VdZ technique. Five had oesophageal atresia (Gross type A or B, Group 1) and five had OA with a dTOF (type C, Group 2) but with a long gap precluding primary anastomosis. Age of first traction procedure was Group 1 = 53 (29-55) days and Group 2 = 3 (1-49) days. Median number of traction procedures = 3; time between first procedure and final anastomosis was 6days (4-7). Four cases were converted to thoracotomy at the third procedure. Three had anastomotic leaks managed conservatively. Follow-up was 12-52months. All patients achieved oesophageal continuity and were orally fed; no patient required an oesophagostomy. In this series, TPETS in LGOA facilitated delayed primary anastomoses and replicated the good results previously described but, in addition, was successful in cases with dTOF. We believe traction suture placement and tensioning benefit from being performed thoracoscopically because of excellent visualisation and the fact that the tension does not change when the chest is closed. Surgical and anaesthetic planning and expertise are crucial. It is now our management of choice in OA patients with a long gap with or without a distal TOF.

Optimizing Individual Wound Closure Practice Using Augmented Reality: A Randomized Controlled Study.

Background Suturing requires repeated practice with guidance to prevent skill deterioration; however, guidance is often limited by expert availability. There is evidence that augmented reality (AR) may assist procedural skill acquisition among learners. This study examines the use of an AR suture guidance application to assist the independent practice of suturing. Methodology A novel suture guidance application was designed for the Microsoft HoloLens. The guidance system included a calibration system and holograms that projected over a suture pad in a stepwise manner. To assess the application, 30 medical students were recruited and randomly assigned to two groups. The control group (n = 16) was given 30 minutes of independent suture practice, while the experimental group (n = 14) utilized the suture guidance application. Both groups completed a pre- and post-test wound closure assessment. After the post-test, the control group trialed the suture guidance application. All participants completed a feedback survey on the application. Statistical analysis was completed using Stata (StataCorp., College Station, TX, USA) with paired Student's t-tests and Welch's t-tests with a significance of 95%. Results Both groups demonstrated a significant improvement in total time and time per stitch during the post-test. Additionally, comparing pre- and post-test assessments in the experimental group revealed a significant improvement in the total number of stitches (p = 0.007), the ratio of bisecting stitches (p = 0.02), and the symmetry of stitch bite (p = 0.03). The feedback survey supported the application for guiding suture placement and spacing. Participants identified limitations in the hologram stability and neck positioning. Conclusions This study suggests the potential to use AR to facilitate the independent practice of wound closure within simulation environments.

Alternating suture and staple placement for linear high-tension scalp wounds: A video walk-through

Alternating suture and staple placement for linear high-tension scalp wounds: A video walk-through

Late iris cerclage suture cheese-wiring.

To describe a case series of cerclage failures due to cheese-wiring; iris repair can develop late cheese-wiring of cerclage sutures with resultant loss of benefits. Cincinnati Eye Institute, Cincinnati, Ohio. Retrospective single-surgeon case series. A retrospective chart review sought patients who underwent iris cerclage at the Cincinnati Eye Institute who later developed suture cheese-wiring. The patient symptoms, demographics, cerclage size, suture type, knot type, iris status, and suture status at final follow-up were ascertained. 6 cases of cerclage suture cheese-wiring with loss of the original surgical benefit were identified. 10-0 polypropylene suture and a 3-1-1 knot were used in each case. The suture remained intact with an intact knot and suture loop in all cases. Cheese-wiring with return of mydriasis is a potential long-term outcome of iris cerclage suture placement, with return of preoperative symptoms. Awareness of this potential eventuality provides physicians and patients a broader perspective when selecting between cerclage suture, iris prosthesis placement, or other surgical and nonsurgical options.

Mapping out an anatomic zone of safety of the presacral space for sacrocolpopexy suture placement

Mapping out an anatomic zone of safety of the presacral space for sacrocolpopexy suture placement

Intraluminal Suture Placement for Management of Hypotony After Glaucoma Drainage Device Surgery.

Intraluminal 3-0 Supramid stent placement can be an effective long-term solution for hypotony after glaucoma drainage device surgery. This procedure may obviate the need for conjunctival dissection. In some cases, additional procedures are required. To describe the utility of implantation of a multifilament polyamide suture (Supramid) in the tube lumen to reverse hypotony after glaucoma drainage device (GDD) surgery. Patients who underwent tube revision with intraluminal placement of a 3-0 Supramid stent, with or without external ligature, to manage hypotony following GDD surgery between January 2010 and October 2020. Resolution of hypotony was defined as IOP >5mm Hg and the absence of hypotony-related structural abnormalities. Overall success was the absence of failure criteria (IOP ≤5mm Hg, >21mm Hg, or <20% reduction below baseline IOP after 3 months for 2 consecutive study visits; additional glaucoma surgery; or loss of light perception), with or without adjunctive ocular hypotensive therapy. Nine eyes of 9 patients underwent placement of a 3-0 Supramid stent with a resolution of hypotony in all eyes with a mean follow-up duration of 33.3 ±24.0 months. Overall success was achieved in 7 of 9 eyes. Four eyes required intervention after stent placement: 1 eye required selective laser trabeculoplasty followed by replacement of the original stent with a shorter 3-0 Supramid suture and external ligature; 1 eye underwent revision for tube exposure; and 2 eyes underwent laser suture lysis to release an external suture ligature. In cases of hypotony after GDD, particularly when it is desirable to reduce the extent of additional conjunctival dissection, intraluminal placement of a 3-0 Supramid stent via an intracameral approach can be an effective long-term solution. Postoperative adjustments were required in many cases.

Biomechanical Analysis of a New Odd-Numbered Strand Suture Technique for Early Active Mobilization After Primary Flexor Tendon Repair

PurposeThe placement of multi-strand sutures during flexor tendon repair is complex and challenging. We developed a new, simpler nine-strand suture, which we term the Tajima nines. The Tajima nines repair method is a new odd-numbered strand tendon technique. MethodsFourteen porcine flexor tendons were transected and repaired using the Tajima nines repair method, without placement of peripheral sutures. This technique is a modification of the Lim and Tsai repair method; it uses a 4-0 monofilament nylon, three-strand line, and two needles. The repaired tendons were tested for linear, noncyclic, load-to-failure tensile strength. The initial gap, 2-mm gap-formation force, and ultimate strength were measured. ResultsThe initial gap-formation force was 27.9 ± 7.5 newtons (N), the 2-mm gap-formation force was 39.2 ± 4.7 N, and the ultimate strength was 76.7 ± 17.2 N. Eight, three, and three of the fourteen tendons repaired using the Tajima nines method demonstrated failure because of thread breakage, knot failure, and suture pull-out, respectively. ConclusionsThis biomechanical study demonstrated that Tajima nines repair was associated with particularly high initial tension at the repair site; there were minor variations in the initial load and 2-mm gap-formation load. Our results suggest that Tajima nines repair with peripheral suturing allows the repaired flexor tendon to tolerate the stresses encountered during early active mobilization. Clinical RelevanceThis simple nine-strand technique will be particularly useful for inexperienced surgeons who perform early active mobilization after primary flexor tendon repair, because the technique is a modification of the Lim and Tsai repair method using a triple strand instead of a double strand.

Corset suture: A novel technique of overlay appositional continuous sutures with air tamponade for management of large acute corneal hydrops.

Management of large acute corneal hydrops (ACH) has always been a challenge. Various medical and surgical management options have been used, such as topical steroids, cycloplegics, antiglaucoma medications, antibiotics, Descemet's membrane reposition, and pre-Descematic sutures, for the management of acute hydrops, but have shown limited benefit. We hereby describe a novel technique of appositional continuous overlay sutures along with air tamponade for surgical management of corneal edema following large ACH. In this technique, the epithelium is scraped to visualize the stromal cleft, and then corneal marking is done to locate the suture placement site. Next, a continuous overlay, 10-0 nylon suture is passed in a crisscross fashion, just like the laces of a corset. A small paracentesis is made to lower the intraocular pressure. Stromal fluid is milked out using two iris spatulas, simultaneous suture tension adjustment is done, and the knot is secured. Appropriate anterior chamber tamponade is achieved using air, paracentesis is hydrated, and a bandage contact lens is applied. We noted complete resolution of corneal edema within 2 weeks of the procedure, with significant improvement in visual acuity.

(021) Eight-Dot Extended Corporotomy versus Conventional Corporotomy for Malleable Penile Prosthesis Implantation

Abstract Introduction To date, malleable type penile prosthesis implantation (MPPI) remains the more popular in developing countries, owing to its relative economic cost. Despite the simplicity of the procedure, there still may be areas of improvement and refinement to optimize procedure efficiency and accuracy subsequently improving postoperative outcomes while reducing complication risk. Objective We aimed to compare the eight-dot extended corporotomy and the conventional corporotomy techniques for MPPI with regard to operative time and postoperative complications. Methods We conducted a prospective randomized interventional clinical study on 51 subjects. Patients were randomized into 2 groups: the eight-dot group (n=27) and the conventional group (n=24). The eight-dot group underwent MPPI using the eight-dot extended corporotomy as previously described (VJPU - Eight-dot Extended Corporotomy: A More Secure, Aesthetic and Time Efficient Technique for Semirigid Penile Prosthesis Implantation, n.d.). The conventional group underwent MPPI using conventional limited corporotomies that were closed via continuous running sutures. We compared both groups in terms of corporotomy opening to closure time, overall procedure time, and perioperative complications. The follow-up period was 3 months. Results Upon timing in seconds (s), a significant time difference between the 2 groups was demonstrated for suture placement, corporotomy incision and implant placement, corporotomy closure, and total procedure duration. Although patients in the eight-dot group required a longer time for suture placement vs the conventional group (486 vs 201 s, respectively, p &amp;lt; 0.001), the durations for the remaining implantation steps, as well as the whole procedure, were significantly shorter for the former group. Corporotomy opening followed by implant placement took significantly less time for the eight-dot group (1090 s) vs the conventional group (1313 s), p &amp;lt;0.001. Moreover, insertion of implant rods was subjectively easier with no need for aggressive bending owing to the extended corporotomy length. Similarly, corporotomy closure using the 8-dot technique was 10.13 minutes swifter than the conventional group (220 s vs. 828 s, respectively, p &amp;lt; 0.001). The total procedure length was over 8 minutes shorter for the eight-dot group as opposed to the conventional group (2527 vs 3027 s, respectively, p &amp;lt; 0.001). In terms of postoperative complications in the form of pain, swelling, hematoma, and infection, there were no significant differences between both groups. Conclusions The eight-dot extended corporotomy technique is a safe and time-saving approach compared to the conventional limited corporotomy technique, making the MPPI procedure more efficient. A swifter procedure decreases both patient exposure to anesthesia and device exposure to air which in turn lowers the risk for potential postoperative complications. Disclosure No.

Innovations in Aortic Valve Replacement: A Comprehensive Overview of the Intuity Rapid Deployment Valve

Rapid deployment/sutureless (RDS) valves have recently emerged as an innovative surgical solution, providing an alternative to traditional methods of surgical aortic valve replacement (SAVR) by eliminating the need for suture placement and tying. This innovation leads to a reduction in aortic crossclamp and cardiopulmonary bypass times, enhancing the efficiency of the procedure. Among the 2 available RDS valves, the Edwards Intuity valve in particular has been demonstrated to be a particularly promising substitute in the field of SAVR. The Intuity valve distinguishes itself from other RDS and conventional valves by yielding superior outcomes, such as a significant reduction in mortality, increase in the longevity of the valve, and a marked decrease in both mean and peak transvalvular pressure gradients. These benefits collectively contribute to its appeal as a favorable new solution. However, further investigation is needed to conclusively determine the long-term outcomes and safety of RDS valves. Nevertheless, the utilization of the Intuity valve presents an exciting solution to the existing limitations of conventional and minimally invasive SAVR, especially for patients afflicted with severe aortic stenosis.

(386) Eight-Dot Extended Corporotomy Versus Conventional Corporotomy for Malleable Penile Prosthesis Implantation

Abstract Introduction To date, malleable type penile prosthesis implantation (MPPI) remains the more popular in developing countries, owing to its relative economic cost. Despite the simplicity of the procedure, there still may be areas of improvement and refinement to optimize procedure efficiency and accuracy subsequently improving postoperative outcomes while reducing complication risk. Objective We aimed to compare between the eight-dot extended corporotomy technique and the conventional corporotomy techniques for MPPI with regards to operative time and postoperative complications. Methods We conducted a prospective randomized interventional clinical study on 51 subjects. Patients were randomized into 2 groups: eight-dot group (n=27) and conventional group (n=24). The eight-dot group underwent MPPI using the eight-dot extended corporotomy as previously described (VJPU - Eight-dot Extended Corporotomy: A More Secure, Aesthetic and Time Efficient Technique for Semirigid Penile Prosthesis Implantation, n.d.). The conventional group underwent MPPI using conventional limited corporotomies that were closed via continuous running sutures. We compared between both groups in terms of corporotomy opening to closure time, overall procedure time and perioperative complications. The follow up period was 3 months. Results Upon timing in seconds (s), a significant time difference between the 2 groups was demonstrated for suture placement, corporotomy incision and implant placement, corporotomy closure, and total procedure duration. Although patients in the eight-dot group required longer time for suture placement vs the conventional group (486 vs 201 s, respectively, p &amp;lt; 0.001), the durations for the remaining implantation steps as well as the whole procedure were significantly shorter for the former group. Corporotomy opening followed by implant placement took significantly less time for the eight-dot group (1090 s) vs the conventional group (1313 s), p &amp;lt;0.001. Moreover, insertion of implant rods were subjectively easier with no need for aggressive bending owing to the extended corporotomy length. Similarly, corporotomy closure using the 8-dot technique was 10.13 minutes swifter than the conventional group (220 s vs. 828 s, respectively, p &amp;lt; 0.001). The total procedure length was over 8 minutes shorter for the eight-dot group opposed to the conventional group (2527 vs 3027 s, respectively, p &amp;lt; 0.001). In terms of postoperative complications in the form of pain, swelling, hematoma, and infection, there were no significant differences between both groups. Conclusions The eight-dot extended corporotomy technique is a safe and time-saving approach compared to the conventional limited corporotomy technique, making the MPPI procedure more efficient. A swifter procedure decreases both patient exposure to anesthesia and device exposure to air which in turn lowers the risk for potential postoperative complications. Disclosure No.

(188) Horizontal Plication and Reduction Corporoplasty for Penile Girth Discrepancy (Christmas Tree Deformity)

Abstract Introduction We present a case of severe Peyronie's Disease, described as the “Christmas tree deformity” due to its crescendo shaped proximal girth discrepancy. This very rare deformity and proposed surgical correction technique have only been described in the literature once beforehand. Objective To depict the surgical correction of the severe penile girth discrepancy in video format. Methods At the start of the case, artificial erection was performed, revealing significant girth discrepancy. The proximal base of the shaft measured 21.5 cm, mid shaft 18.5 cm, and distal shaft 12 cm (Image 1). A circumcising incision was made and a plane along Buck’s fascia developed. Using careful blunt and sharp dissection, left and right neurovascular bundles were carefully elevated and gently lifted to the midline to allow for plication suture placement laterally. An artificial erection was again created, revealing significant asymmetry with 9.5cm girth discrepancy between proximal and distal shaft. Plication sutures of 1-0 Ethibond were placed using a “1+1=2” dot horizontal plication pattern, starting at the base and progressing to mid shaft on both the left and right sides. Plication sutures were placed systematically until symmetric girth was confirmed using artificial erection. A TachoSil graft was then placed along the shaft to decrease likelihood patient would feel the numerous Ethibond sutures below and also improve hemostasis. Dartos fascia was then closed with a Vicryl suture and the circumcising incision closed in a running subcuticular fashion. Again, artificial erection showed drastic improvement in penile girth magnitude and symmetry. A penile block was performed and the penis was wrapped in Kerlix gauze and coban. Results The patient was discharged on the same-day of surgery with oral pain medications. He was seen back in follow-up at 8 weeks postoperatively at which time he endorsed an uneventful recovery and that he was once again able to have penetrative intercourse with his partner. Conclusions We are proud to report on the second known case of horizontal plication and reduction corporoplasty for correction of severe penile girth discrepancy, “Christmas tree deformity.” Despite a lack of available literature on the deformity and surgical technique, we believe it is a safe and effective treatment option for patients with this rare form of Peyronie's. Disclosure No.

A customized technique for confluent aortic annular and selective sinus of Valsalva endocarditis.

We describe a novel technical modification for reoperative aortic valve replacement in destructive recurrent prosthetic aortic valve endocarditis. We encountered complex anatomy in a previously operated aortic root wherein the aortic annulus and the right coronary sinus of Valsalva were destroyed. This precluded secure suture placement. We modified a composite mechanical Valsalva conduit to create a separate sinus of Valsalva left in continuity with the mechanical valve. This approach allowed us to exclude the infected right sinus of Valsalva and the corresponding aortic annulus.

Intraoperative indocyanine green imaging as an adjunctive technique to reduce any circumflex artery damage during mitral valve surgery: a feasibility study.

Iatrogenic injuries to the circumflex coronary artery during mitral valve surgery are probably underestimated (reported rates of 0.3-1.8%). This complication arises from the artery's close proximity to the mitral annulus, particularly at the anterolateral commissure. The study aimed to assess this risk in a patient group prone to such injury. The surgical procedure utilized a minimally invasive approach and indocyanine green-based fluorescence imaging. This technique allows a real-time visualization of the circumflex artery, aiding precise placement of annular sutures and minimizing the risk of injury. The method, applied in 6 patients, integrates preoperative assessments with intraoperative fluorescence imaging, ensuring accurate arterial depiction and preventing iatrogenic damage. The study highlights the safety and efficacy of fluorescence imaging, especially in identifying vessel anomalies, indicating potential applications in various cardiac procedures.

Thickness of the Medial Pretarsal Adipose Tissue in the Upper Eyelid among the Japanese Population.

To investigate the medial pretarsal adipose tissue thickness of the upper eyelid in the Japanese population. Sixty-two whole upper eyelids were harvested from 35 Japanese cadavers and fixed in paraffin. The samples were cut into 5 µm sagittal microsections and stained with hematoxylin and eosin, as well as Masson's trichrome. Data obtained from images and measurements were taken with Aperio ScanScope and ImageScope software and underwent statistical analysis. The samples were divided into 3 shapes sagittal cross-sections of the eyelid (triangular, rectangular, and flat) corresponding to the shape of the medial pretarsal adipose tissue. Type I (triangular shape, 48.4%) had a ratio of fat thickness at 1⁄2 tarsal height to peak fat thickness of <0.9, and type IIa (rectangular shape, 30.6%) and IIb (flat shape, 21.0%) had pretarsal adipose tissue thickness to tarsal height ratio of ≥0.2 and <0.2, respectively. The mean values of tarsal thickness at 1⁄2 tarsal height were 1021 µm for the type I group, 1100 µm for the type IIa group, and 764.4 µm for the type IIb group ( p = 0.01). The mean values of fat thickness at 1⁄2 tarsal height were 410.6 µm for the type I group, 303.3 µm for the type IIa group, and 242.6 µm for the type IIb group ( p = 0.26). The thickness of the medial pretarsal adipose tissue was different according to the shape of the sagittal cross-section of the eyelid. Awareness of the medial pretarsal adipose tissue thickness contributes to effective suture placement and safe suture depth during blepharoptosis surgery.

Simulation-based training for endoscopic mitral valve repair: the impact on basic surgical skills for placement of sutures at mitral valve annulus during 2-h training workshop.

The aim of this study was to evaluate the impact of simulation-based training on surgical skills during 2-h learning labs during surgical annual meeting. During the 36th European Association of Cardiothoracic Surgery annual meeting a learning drylab for simulation-based training for endoscopic mitral valve repair was set up. For this purpose, a validated high-fidelity endoscopic mitral valve surgery simulator and a validated suturing map were used. The training lasted 2 h. Technical pre- and post-assessment were carried out based on time and accuracy to place a suture at the posterior mitral valve annulus. The suture had to be placed within 60 s. The suture was considered anatomically correct if it entered and exited the annulus at the designated place (on the posterior annulus) and accurate if placed within the right width (8-12 mm). In total, 46 participants were included in this study, of whom 18 (38%) were experienced/staff surgeons, 23 (51%) fellows and 5 (11%) residents. Before the training, 48% of the participants failed to place any suture for pre-assessment. After completing the training, 100% of the participants succeeded in placing an anatomically correct suture. There was a significant improvement in the time taken [pre-assessment mean 45 (standard deviation: 25) s vs post-assessment mean 18 (standard deviation: 12) s, P < 0.001] and the accuracy to place a suture in the mitral valve annulus after completing the training (pre-assessment 32.6% vs post-assessment 65.2%, P < 0.001). This study shows a significant improvement in endoscopic skills for mitral valve surgery after completing a 2-h training with a high-fidelity endoscopic mitral valve surgery simulator. This suggests that simulation trainings during scientific annual meetings are effective on surgical skills.

Preterm membranes are mechanically more resistant than term membranes.

To compare the biomechanical properties of fetal preterm membranes (20+0weeks to 30+0weeks) to those of the term (37+0 to 41+0weeks). Amnion and chorion were manually separated and samples were cut to the required geometry. Rectangular samples with (mode 1) and without (uniaxial) a notch, were tested for tearing energy, critical elongation, and tangent stiffness. Suture retention and inter-suture distance testing investigated the effect of suture placement. From the 15 preterm and 10 term placentas studied, no notable differences were observed in uniaxial testing. Mode 1 fracture testing showed a difference in tearing energy between the preterm and term chorion (0.025±0.005 vs. 0.017±0.005J/m-1 ; p=0.027) but not in the amnion (0.030±0.017 vs. 0.029±0.009J/m-1 ; p=0.895). Both preterm amnion and chorion showed a higher critical elongation compared with term (1.229±0.057 vs. 1.166±0.046; p=0.019 and 1.307±0.049 vs. 1.218±0.058; p=0.012). Preterm amnion had a higher suture retention strength than its term counterpart (0.189±0.065 vs. 0.121±0.031N; p=0.023). In inter-suture distance tests, no significant interaction was observed beyond 3mm, but the preterm chorion showed less interaction at 1-2mm distances. Preterm membranes have equivalent or superior tensile properties to term membranes. The chorion appears to contribute to the mechanical integrity of fetal membranes, particularly in preterm stages.