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

A Comparison of Times Taken for the Placement of the First Portal and Complication Rates between the Veress Needle Technique and the Modified Hasson Technique in Canine Ovariectomy Laparoscopic Surgery

Minimally invasive surgery is increasingly being used in veterinary medicine. Laparoscopic procedures have several advantages compared with open surgery. These include the magnification of the field of surgery, reduced post-surgical pain and associated stress, reduced post-operative infection rates, and decreased hospitalization time. The establishment of a pneumoperitoneum is a critical step; however, this procedure can prolong the operation time, and most of the complications associated with laparoscopic surgery have been attributed to the insertion of devices into the abdominal cavity. Two main techniques have been employed to create pneumoperitoneum: the closed-entry method using the Veress needle and the open Hasson technique. The first portal is necessary to start insufflation and, subsequently, to realize the operative channel to insert the laparoscopic instruments into the abdomen. Many authors have compared the time necessary to create the first portal using different techniques in human medicine, but studies on this topic in veterinary medicine are lacking. In the veterinary medicine literature, complications associated with the creation of a pneumoperitoneum and the placement of ports include spleen, bowel, or bladder injuries; pneumothorax; and subcutaneous emphysema. The aim of the present study was to compare the times required for the placement of the first portal and the creation of pneumoperitoneum, and the rates of intraoperative complications using the Veress needle technique (VNT) and the open modified Hasson technique (MHT). The sample population comprised 30 female dogs who underwent laparoscopic ovariectomies. The dogs were randomly organized into two groups and two different entry techniques were used: Veress needle (VNT = group A) and the modified Hasson technique (MHT = group B). Complications related to abdominal entry were classified as major, in cases of organ perforation, and minor, in cases of subcutaneous emphysema and gas leakage. The VNT and MHT required 374.0 s and 242.9 s, respectively, for the placement of the first portal and for establishing pneumoperitoneum (p < 0.05). Their major complications rates were 20% and 0%, respectively (p < 0.05). Their minor complications rates were 20% and 35%, respectively (p < 0.05). No surgical procedures required laparotomy. The MHT was associated with a lower major complication rate and required less time to create the first portal, compared with the Veress needle technique.

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.