Comparison of design features and mechanical properties of commercially available Veress needles

Complications related to entry techniques for laparoscopy in 159 dogs and cats

OBJECTIVE

To report the frequency and risk factors of complications related to 3 entry techniques for laparoscopy in small animals.

STUDY DESIGN

Single-institution retrospective case series.

ANIMALS

159 client-owned dogs and cats.

METHODS

Medical records were reviewed for dogs and cats undergoing laparoscopic surgery with carbon dioxide (CO₂ ) insufflation between 2006 and 2018. Data including entry site, entry technique, signalment, body conformation, complications, and operating surgeon/resident were analyzed by univariate regression analysis. Factors with P < .25 were included in multivariate regression analysis.

RESULTS

Complications occurred in 33 of 159 (21%) surgeries and were considered minor (CO₂ leaks, omental insufflation, repeated entry) in 30 of 33 (91%) cases. The Ternamian visual entry, modified Hasson, and Veress needle entry techniques were associated with complications in 7 (9%), 17 (26%), and 9 (60%) surgeries, respectively. Major complications occurred in 3 of 159 (2%) surgeries, in which entry-related hemorrhage prompted conversion to an open technique (2 [13%] entries with Veress needle) and 1 [1%] with the Ternamian visual). Entry location and entry technique remained significant in the final multivariate model. Complications were 11.7 times more likely after a paramedian entry than after a midline entry; the odds ratio of complications were 5 and 28 times higher after modified Hasson and Veress needle entries, respectively, than after Ternamian visual entry.

CONCLUSION

In this study, a Ternamian visual entry technique and midline entry site appeared associated with fewer complications than 2 other techniques.

CLINICAL SIGNIFICANCE

The findings in this study are preliminary, and superiority of any entry technique must be reevaluated in a prospective randomized controlled study.

Influence of 2 Veress needles and 4 insertion sites on Veress needle penetration depth: A comparative study in cadaveric dogs

Objective

To evaluate the penetration depth (VNPD) of 2 disposable Veress needles (VN) at 4 insertion sites in the abdomen.

Study design

Descriptive study.

Sample population

Canine cadavers (n = 22, 6 for confirmation of the test methods and 16 for the comparative study).

Methods

Two disposable VN (VN A and VN B) were inserted at 4 sites (9th intercostal space [ICS] and preumbilical, paraumbilical, and subumbilical sites) in dorsally recumbent dogs by using a hand‐cranked jig. The VNPD was measured as the distance traveled by the VN between the subcutaneous tissue and the perforation of the peritoneum on the basis of audible clicks and visible feedback from the VN. The effects of the VN type and insertion site on the VNPD were analyzed by using a linear mixed‐effects model.

Results

VNPD varied between insertion sites (P =  .01) and VN (P < .01). The VNPD was less at the 9th ICS than at the preumbilical, paraumbilical, and subumbilical sites. The maximal magnitude of change was 7.4 mm. Veress needle B (with a low spring rate, lower forces, and a back‐cut bevel design) penetrated farther than VN A (with a high spring rate, high forces, and a lancet‐type bevel) at 3 of 4 insertion sites. The maximal magnitude of change was 6.8 mm.

Conclusion

Veress needle penetration depth varied between VN designs but was the least at the 9th ICS in canine cadavers.

Clinical significance

Insertion of a VN at the 9th ICS is recommended to minimize its penetration into the abdomen. Associations between VNPD and mechanical factors, such as the sharpness and spring rate of VN, warrant additional research.