Novel method of the double-loop slip-knot: preknotting on the laparoscopic forceps enables easy and secure intracorporeal ligation

In vitro holding strength of the laparoscopic Miller's knot compared with open Miller's knot, open surgeon's throw, and laparoscopic surgeon's throw in a vascular pedicle model

OBJECTIVE

To compare in vitro knot holding strength of the laparoscopic Miller's knot (LMK), open Miller's knot (MK), open surgeon's throw (Sx), and laparoscopic surgeon's throw (LSx) in a vascular pedicle model when used as the first throw for vascular ligation.

STUDY DESIGN

Experimental study.

SAMPLE POPULATION

Ten constructs each of the Miller's knot and surgeon's throw performed openly and laparoscopically with 2-0 polyglyconate suture.

METHODS

Knot holding strengths of the LMK, MK, LSx, and Sx knots were evaluated on balloon dilation catheters used as vascular pedicle models. Laparoscopic knots were tied in a laparoscopic box trainer. Knot constructs were pressure tested to failure. Results were compared by Kruskal-Wallis and Steel-Dwass comparisons.

RESULTS

Both MK and LMK had mean leakage pressures above 300 mm Hg. The MK leaked at higher pressure than all other knots, including the LMK (P < .001). The LMK leaked at greater pressures compared with the Sx and the LSx (P < .001). No difference was detected between leaking pressures of the Sx and the LSx (P = .226), with both leaking at pressures below 40 mm Hg.

CONCLUSION

The LMK created a more secure first throw compared with the Sx and leaked at supraphysiologic pressures.

CLINICAL SIGNIFICANCE

The LMK has excellent knot holding strength on a vascular pedicle model and may be further evaluated for clinical application.

Can We Use the Disposable Laparoscopic Clip Appliers as Suture Anchors? An In Vitro Feasibility Study

INTRODUCTION

Intracorporeal suturing is time-consuming and could be difficult in certain operative circumstances. Instead of knot tying, specially designed clips have been introduced to anchor and secure the end of a single strand or suture. Although these clips provide a maximal required holding grip (HG), they considerably increase the cost of the procedure. The aim of this in vitro study was to identify the feasibility, and means of achieving the best HG, of commonly used disposable automatic clip appliers (LCAs) over regular strands.

METHODS

We placed 2-0 PDS (rigid) and 2-0 Vicryl (soft) sutures through fresh gastric wall specimens. Six different commercial-type LCAs, all having large or medium/large clips, were applied at the distal end of each suture. An IMDA manual digital force gauge was used to measure the HG of each clip at 2 positions: the middle clip position and the angle (at the crouch) position. A total of 192 measurements were taken. The results were classified into 3 HG levels measured by Newton units (N): the strongest grip (> 1 N), medium grip (> 0.5 and < 1 N), and weak grip (< 0.5 N).

RESULTS

The strongest HG was obtained by applying 10 to 12 mm LCAs with large or medium/large clips over PDS at an angle position (HG = 1.1 ± 0.2 to 1.6 ± 0.3 N). The weakest grip was obtained by applying any type of LCA over Vicryl at the middle position (HG = 0.08 ± 0.04 to 0.2 ± 0.06 N, P < 0.001). The latter was associated with clips freely falling off the sutures even before applying any force. In general, more force was needed to dislodge any brand clip from the PDS compared with Vicryl suture (0.8 ± 0.6 vs. 0.4 ± 0.3 N, P < 0.001). The angle position was always stronger than the middle position (0.9 ± 0.6 vs. 0.3 ± 0.2 N, P < 0.001). There was a trend for the 10 to 12 mm LCA to have a better HG than the 5 mm ones (0.65 ± 0.5 vs. 0.51 ± 0.5 N, P = 0.08).

CONCLUSIONS

We propose that 10 to 12 mm LCAs generate enough HG to secure a single strand when clips are placed at the angle position. This is especially true over PDS (hard) strands. The application of 5 mm LCA clips to secure the end of the Vicryl strand is not recommended. Further clinical studies are warranted.