A laparoscopic knot-tying device for minimally invasive cardiac surgery

Prosthesis-prosthesis anastomosis using barbed sutures compared to conventional sutures under high, long-term pressure; in vitro extracorporeal circulation setup

BACKGROUND

While barbed sutures have been extensively utilized in other disciplines, they have not been widely adopted in cardiac surgery. The lack of safety and feasibility data has limited its use within the field. To aide in the further understanding of how cardiac surgeons can use barbed sutures, we sought to develop a high-pressure in vitro simulation model. We compared knotless barbed sutures in a highly pressurized anastomosis to conventional sutures.

METHODS

Ten specimens in total were utilized in prosthesis anastomosis, using 34 mm Gelweave Plexus (Terumo Aortic, Sunrise, FL 33325, USA) and 34 mm Hemabridge (Intergard Woven Hemabridge, Getinge, Göteborg, Sweden). Five models of size 3-0 barbed suture anastomoses using non-absorbable, barbed, self-retaining, monofilament polypropylene sutures (Filbloc® 3-0, Assut Europe, Rome, Italy) were compared against five conventional anastomoses using size 4-0 polypropylene monofilament (Ethicon, USA). The systems were connected using a novel-designed extracorporeal circulation system. Pressure was rapidly increased in the specimen to a mean pressure of 300-350 mmHg, running then for a minimum of 48 hours to assess anastomosis strength and endurance.

RESULTS

No anastomotic dehiscence or rupture was recorded. Complex, angular anastomosis required extra stitch leakage sutures in both conventional and barbed suture specimens.

CONCLUSION

Using knotless barbed sutures with an additional self-locking maneuver for prosthesis-prosthesis anastomosis in cardiac surgery is feasible in an in vitro model under long term, high-mean pressure when compared to conventional sutures. In vivo trials should be performed to further validate the in vitro findings.

Beyond the Square knot: A validation study for a novel knot-tying method named "inverse 9"

Purpose

We compared the "inverse 9" laparoscopic suturing and knot-tying (LSKT) method to the traditional LSKT method in a validation study to demonstrate the "inverse 9" method's superiority and effectiveness in laparoscopy.

Methods

On the basis of their experience in laparoscopic surgery, 78 trainees were divided into two groups, with 52 inexperienced trainees in group A and 26 experienced trainees in group B. In group A, 52 trainees were randomly allocated to either group A1 ("inverse 9" LSKT training) or group A2 (traditional LSKT training). In group B, experienced trainees were randomly assigned to receive "inverse 9" LSKT training (group B1) or continuing training in the traditional LSKT method (group B2). All trainees received the same instruction and assessment and were asked to provide a subjective assessment of the two training methods at the end of the training.

Results

The trainees in groups A1, A2, and B had similar average ages and were mostly male. After training, all showed preliminary mastery of LSKT (P < 0.05). The trainees in groups A1 and B1 achieved learning proficiency in the fifth assessment, while those in group A2 achieved it in the sixth assessment. The trainees in groups A1 and B1 showed lower difficulty in achieving mastery and lower operation fatigue scores (P < 0.05), and 61.50 % of the trainees in group B preferred the "inverse 9" method in subjective evaluation.

Conclusion

As a novel LSKT technique, "inverse 9" offers a multitude of benefits. In addition to ensuring a simpler operation and effectively reducing the knot-tying time, it also involves a shorter learning curve than traditional LSKT methods. As such, it can be easily mastered and widely adopted as a standard LSKT technique.

Safety and Performance Evaluation of Su2ura Approximation, a New Suturing Device, in Pigs

One of the challenging aspects of minimal invasive surgery (MIS) is intracorporal suturing, which can be significantly time-consuming. Therefore, there is a rising need for devices that can facilitate the suturing procedure in MIS. Su2ura Approximation Device (Su2ura Approximation) is a novel device developed to utilize the insertion of anchors threaded with stitches to allow a single action placement of a suture. The objective of this study was to evaluate the long-term safety and tissue approximation of Su2ura Approximation in comparison to Endo Stitch + Surgidac sutures in female domestic pigs. All incision sites were successfully closed by both methods. Firm consolidation within and around the incision site was noted in several animals in both treatment groups, which corresponded histopathologically to islands of ectopic cartilage or bone spicules within the fibrotic scar. These changes reflect heterotopic ossification that is commonly seen in the healing of abdominal operation sites in pigs. No other abnormal findings were observed throughout the study period. In conclusion, the use of Su2ura Approximation under the present experimental conditions revealed no safety concerns.

A Novel Shape-Memory Monofilament Suture for Minimally Invasive Thoracoscopic Cardiac Surgery

OBJECTIVES

Endoscopic knot tying can complicate or prolong minimally invasive surgical procedures. A novel shape-memory monofilament suture with a spiral tail has been developed to speed up suture fixation during minimally invasive cardiac surgery. The purpose of this study was to evaluate its usefulness and safety in minimally invasive cardiac surgery.

METHODS

We installed a needle with a 4-0 monofilament suture, composed of polyvinylidene difluoride and hexafluoropropylene copolymers, in an originally invented jig and heated it in an oven. By only passing through the needle and then into the spiral made at the tail of the suture, a hangman's knot was easily made. For the fundamental experiment, to evaluate the effectiveness of the novel shape-memory monofilament suture, 4 surgeons with varying thoracoscopic experience tied knots within a simulated minimally invasive setting, using both the novel shape-memory and conventional monofilament sutures. The time elapsed for knot tying and tensile strength of each knot was measured.

RESULTS

The mean knot-tying time was significantly shorter with the novel suture than with the conventional suture (108 ± 29 vs. 172 ± 42 seconds, P = 0.01). The ultimate tensile strength of each knot was 17.4 N in the novel suture and 16.5 N in the conventional suture.

CONCLUSIONS

The novel shape-memory monofilament suture has great potential for reducing operative time of minimally invasive thoracoscopic surgery while retaining the strength of the knot.

Non-aqueous, tissue compliant carbene-crosslinking bioadhesives

Surgical adhesives are an attractive alternative to traditional mechanical tissue fixation methods of sutures and staples. Ease of application, biocompatibility, enhanced functionality (drug delivery) are known advantages but weak adhesion strength in the wet environment and lack of tissue compliant behavior still pose a challenge. In order to address these issues, non-aqueous bioadhesive based on blends of polyamidoamine (PAMAM) dendrimer, conjugated with 4-[3-(trifluoromethyl)-3H-diazirin-3-yl] benzyl bromide (PAMAM-g-diazirine) and liquid polyethylene glycol (PEG 400) has been developed. PEG 400 biocompatible solvent reduces the viscosity of PAMAM-g-diazirine dendrimer without incorporating aqueous solvents or plasticizers, allowing application by syringe or spray. Upon UV activation, diazirine-generated reactive intermediates lead to intermolecular dendrimer crosslinking. The properties of the crosslinked matrix are tissue compliant, with anisotropic material properties dependent on the PEG 400 wt%, UV dose, pressure and uncured adhesive thickness. The hygroscopic PAMAM-g-diazirine/PEG 400 blend was hypothesized to absorb water at the tissue interface, leading to high interfacial adhesion, however porous matrices led to cohesive failure. The hydrophilic nature of the polyether backbone (PEG 400) shielded cationic PAMAM dendrimers with cured bioadhesive film displaying significantly less platelet activation than neat PAMAM-g-diazirine or PLGA thin films.

Automated Titanium Fasteners Versus Hand-Tied Knots: A Randomized Controlled Trial

BACKGROUND

The relative benefits of automated titanium fasteners (LSI Solutions, Victor, NY) have not been examined in patients undergoing sternotomy. The aim of this study was to assess the time and cost required for suture fixation with the automated device versus conventional hand tying in sternotomy for mitral or tricuspid ring annuloplasty.

METHODS

Fifty patients scheduled to undergo primary mitral or tricuspid, or both, ring annuloplasty-based valve repair operation by a single surgeon were randomly assigned to receive either conventional hand-tied knots or automated titanium fasteners, with 25 patients in each group. The primary outcome variable was the time required to affix the annuloplasty device to the valve annulus.

RESULTS

The times taken to affix a mitral annuloplasty band or ring were 6.1 ± 0.9 min for manual tying versus 3.1 ± 0.4 min for automated fasteners (p < 0.0001); when calculated per annuloplasty stitch, the values were 22 ± 2 s versus 12 ± 1.1 s, respectively (p < 0.0001). The corresponding values for tricuspid annuloplasty were 4.2 ± 1.2 min (hand tying) versus 2.2 ± 0.3 min (automated fasteners) (p = 0.0005), and the times for each suture were 20 ± 2.1 s versus 13 ± 2 s, respectively (p = 0.0004). The use of the automated fastener had no significant impact on aortic cross-clamp time or cardiopulmonary bypass duration. Total cost associated with annuloplasty fixation with automated titanium fasteners (device cost in addition to operating room time cost) was significantly higher than with hand tying ($1,190 ± 374 vs $164 ± 60; p < 0.0001).

CONCLUSIONS

Using the automated fastener to facilitate annuloplasty fixation through a sternotomy resulted in a small procedural time savings (average of 10 s/stitch) that had no overall impact on cardiopulmonary bypass or cross-clamp times but added an average cost of $1,026 to the operation.

Use of an Automated Suture Fastening Device in Minimally Invasive Aortic Valve Replacement

BACKGROUND

Minimally invasive aortic valve replacement (mAVR) is gaining clinical acceptance; however, it is associated with increased operative times because of the limited surgical field and access. The Cor-Knot (CK; LSI Solutions, Victor, NY) is an automated fastening device designed to facilitate suture fastening, but clinical data in mAVR are lacking.

METHODS

From May 2014 to February 2017, 92 patients underwent mAVR at Spectrum Health in Grand Rapids, Michigan; 39 valves were secured with manually tied sutures, and 53 valves were entirely secured with the CK device. Preoperative characteristics and 30-day outcomes data were extracted from the local The Society of Thoracic Surgeons database and the patients' electronic medical records. Survival data were obtained from the Michigan State Social Security Death Index.

RESULTS

No significant differences in preoperative characteristics were noted between the two groups. Aortic cross-clamp time (72 ± 12 minutes vs 82 ± 15 minutes; p = 0.001) was significantly shorter with CK. There was no difference in the rate of postoperative mortality (0% vs 0%), stroke (0% vs 1.9%), atrial fibrillation (28% vs 33%), renal failure (0% vs 3.8%), or pacemaker implantation (5.1% vs 5.7%) between patients with manually tied sutures and patients with sutures fastened with the CK. Valve function on postoperative echocardiography and 1-year patient survival rates were similar.

CONCLUSIONS

In mAVR, the CK device was associated with reduced aortic cross-clamp time while providing equivalent clinical outcomes. Larger studies are needed to confirm the efficacy, safety, and cost-effectiveness of the CK device in minimally invasive aortic valve surgery.

Advances in laparoscopic surgery in urology

In the past 10 years, laparoscopy has been challenged by robotic surgery; nevertheless, laparoscopic techniques are subject to continuous change. Ultrahigh definition is the next development in video technology, it delivers fourfold more detail than full high definition resulting in improved fine detail, increased texture, and an almost photographic emulsion of smoothness of the image. New 4K ultrahigh-definition technology might remove the current need for the use of polarized glasses. New devices for laparoscopy include advanced sealing devices, instruments with six degrees of freedom, ergonomic platforms with armrests and a chest support, and camera holders. A manually manipulated robot-like device is still at the experimental stage. Robot-assisted surgery has substantially revolutionized laparoscopy, increasing its distribution; however, robot-assisted surgery is associated with considerable costs. All technical improvements of laparoscopic surgery are extremely valuable to further simplify the use of classical laparoscopy.

Automated fastener versus manually tied knots in minimally invasive mitral valve repair: impact on operation time and short- term results

Background

This study compares the influence of two different annuloplasty attachment suture applications, namely the use of an automated fastener versus manually tied knots using a traditional knot pusher, on total operation time, on cardiopulmonary-bypass time and on cross-clamp time, and on short-term outcome.

Methods

Sixty patients underwent isolated minimally invasive mitral valve repair in Carpentier Type-II mitral disease with implantation of an annuloplasty ring in combination with correction of the prolapsing leaflet using artificial chords. The first 30 patients after implementation of a novel automated fastener were compared with the last 30 patients corrected with a traditional knot pusher. No significant differences with regard to demographic data (age, gender, NYHA class, ejection fraction, BMI, cardiovascular risk factors) between the two groups were found. All patients received isolated mitral valve repair in the first run. Bretschneider HTK was used for cardioplegic cardiac arrest in all patients.

Results

Transesophageal and transthoracic echocardiography at the end of operation and at discharge revealed no (n = 25), trace (n = 28) or mild (n = 7) residual regurgitation with no evidence of ring dehiscence and without any significant clinical differences between the groups. Cross-clamp, cardiopulmonary-bypass and total- operation time were significantly reduced in the automated fastener group compared to the group using a traditional knot pusher (87.1 ± 17.9 vs. 101.3 ± 17.8; p < 0.01, 138.1 ± 25.6 vs. 152.7 ± 24.9; p < 0.05, and 203.9 ± 31.02 vs. 223.8 ± 29.01; p < 0.01, respectively).

Conclusion

Our short-term results indicate a safe, reliable and fast application of the novel automated fastener device in combination with significant time savings in cardioplegic arrest and cardiopulmonary bypass.

Shalaby technique for efficient single incision laparoscopic pediatric inguinal hernia repair

BACKGROUND

The desire to reduce incision related morbidity and pain while achieving improve cosmetic results has recently led to the introduction of single incision pediatric endosurgery [SIPES]. Over the last few years, SIPES has been increasingly used for a variety of procedures; single incision laparoscopic hernia repair [SILHR] is perhaps its common application. Intracorporeal suturing and knot tying during SIPES remain one of the most challenging tasks. The aim of this study is to present a novel technique to avoid excessive purposeless movements during SILHR in children.

PATIENTS AND METHODS

One-hundred and fifty patients with 170 hernial defects were subjected to SILHR during the period from June 2009 to October 2011. Extraperitoneal saline was injected around internal inguinal ring [IIR] in males. The opened IIR was closed by percutaneous insertion of purse string suture using Reverdin Needle (RN) with intracorporeal suture tie. The main outcome measurements were; feasibility of the technique, tightness of the suture tie, operative time, postoperative hydrocele formation, recurrence rate, and cosmetic results.

RESULTS

Ages ranged between 6 months and 7 years (mean 2±24.2years). There were 101 males and 49 females. Eighty-four patients presented with right sided inguinal hernia, 46 patients with left sided hernia, and 20 patients with bilateral hernia. The mean operative time was 12.4±1.7min for unilateral cases and 18.6±1.7min for the bilateral cases. On follow-up, there were only 1 case of recurrence and 3 cases of hydrocele and the scar is nearly invisible.

CONCLUSION

The preliminary results of this study showed that our technique is very promising to achieve secure closure of IIR and reduced operative time with excellent cosmetic results.

Smart tissue anastomosis robot (STAR): a vision-guided robotics system for laparoscopic suturing

This paper introduces the smart tissue anastomosis robot (STAR). Currently, the STAR is a proof-of-concept for a vision-guided robotic system featuring an actuated laparoscopic suturing tool capable of executing running sutures from image-based commands. The STAR tool is designed around a commercially available laparoscopic suturing tool that is attached to a custom-made motor stage and the STAR supervisory control architecture that enables a surgeon to select and track incisions and the placement of stitches. The STAR supervisory-control interface provides two modes: A manual mode that enables a surgeon to specify the placement of each stitch and an automatic mode that automatically computes equally-spaced stitches based on an incision contour. Our experiments on planar phantoms demonstrate that the STAR in either mode is more accurate, up to four times more consistent and five times faster than surgeons using state-of-the-art robotic surgical system, four times faster than surgeons using manual Endo360(°)®, and nine times faster than surgeons using manual laparoscopic tools.

Single instrument intracorporeal knot tying during single port laparoscopic hernia repair in children: a new simplified technique

BACKGROUND

With the increasing number of open surgical procedures shifting to laparoscopy, laparoscopic suturing and knot tying are becoming integral parts of the skills that any laparoscopist must acquire. It is the most difficult step in laparoscopic surgery, especially in single incision pediatric endosurgery (SIPES). It needs special laparoscopic skills and very long learning curve. The aim of this study is to introduce a new simplified technique for single instrument intracorporeal suture tying during single incision laparoscopic hernia repair (SILHR).

PATIENTS AND METHODS

This study was conducted at Al-Azhar University Hospitals between June 2008 and June 2010. Three-hundred and eighty three patients with 402 congenital inguinal hernias were subjected to SILHR using percutaneous insertion of purse string suture by Reverdin Needle (RN) with single instrument intracorporeal suture knot tie.

DESCRIPTION OF THE TECHNIQUE

Under general endotracheal tube anesthesia, a 0.8-1.2-cm. longitudinal transumilical skin incision was done for insertion of the umbilical port and a 3-mm Maryland forceps. RN was used for insertion of a purse string suture with single instrument intracorporeal suture tie around internal inguinal ring (IIR). The purse-string knot airtightness was stress-tested by raising the intraperitoneal CO2 pressure to 16-24mm Hg for about 30seconds.

RESULTS

A total of 383 patients with 402 congenital inguinal hernias were subjected to SILHR. They were 304 males and 79 females with a mean age of 2.2±2.25years. A single instrument technique was used for intracorporeal suture knot tie and all cases were completed laparoscopically without conversion. The mean operative time was 12.5±3.3minutes for unilateral hernia repair and 17±4.37 for bilateral cases. All patients achieved full recovery without intraoperative or postoperative complications.

CONCLUSION

Single instrument intracorporeal suture tie is feasible, simple, and rapid as it resulted in marked decrease of operative time. It is of low cost, secure and gives great help during SIPES surgery without struggling. It is a good alternative option to extra corporeal knot tying.

Automation of a suturing device for minimally invasive surgery

BACKGROUND

In minimally invasive surgery, hand suturing is categorized as a challenge in technique as well as in its duration. This calls for an easily manageable tool, permitting an all-purpose, cost-efficient, and secure viscerosynthesis. Such a tool for this field already exists: the Autosuture EndoStitch(®). In a series of studies the potential for the EndoStitch to accelerate suturing has been proven. However, its ergonomics still limits its applicability. The goal of this study was twofold: propose an optimized and partially automated EndoStitch and compare the conventional EndoStitch to the optimized and partially automated EndoStitch with respect to the speed and precision of suturing.

METHODS

Based on the EndoStitch, a partially automated suturing tool has been developed. With the aid of a DC motor, triggered by a button, one can suture by one-fingered handling. Using the partially automated suturing manipulator, 20 surgeons with different levels of laparoscopic experience successfully completed a continuous suture with 10 stitches using the conventional and the partially automated suture manipulator. Before that, each participant was given 1 min of instruction and 1 min for training. Absolute suturing time and stitch accuracy were measured. The quality of the automated EndoStitch with respect to manipulation was tested with the aid of a standardized questionnaire.

RESULTS

To compare the two instruments, t tests were used for suturing accuracy and time. Of the 20 surgeons with laparoscopic experience (fewer than 5 laparoscopic interventions, n=9; fewer than 20 laparoscopic interventions, n=7; more than 20 laparoscopic interventions, n=4), there was no significant difference between the two tested systems with respect to stitching accuracy. However, the suturing time was significantly shorter with the Autostitch (P=0.01). The difference in accuracy and speed was not statistically significant considering the laparoscopic experience of the surgeons. The weight and size of the Autostitch have been criticized as well as its cable. However, the comfortable handhold, automatic needle change, and ergonomic manipulation have been rated positive.

CONCLUSION

Partially automated suturing in minimally invasive surgery offers advantages with respect to the speed of operation and ergonomics. Ongoing work in this field has to concentrate on minimization, implementation in robotic systems, and development of new operation methods (NOTES).