Laparoscopic Insertion of Various Shaped Trocars in a Porcine Model

Does the angle of trocar insertion affect the fascial defect caused? A porcine model

INTRODUCTION

With an incidence of 0-5.2%, trocar site hernias frequently occur following laparoscopy. It is unclear to what extent the angle of trocar insertion affects the size of the fascial defect caused. Hence, we performed a porcine model.

METHODS

In October 2022, a total of five female pigs were euthanized. In alternating order, three bladeless and two bladed conical 12-mm trocars were inserted at an angle of 45° on each side for 60 min twice each pig. For this purpose, an epoxy resin handmade cuboid with a central channel that runs at an angle of 45° was used. Subsequently, photo imaging and defect size measurement took place. The results were compared with those of our previously conducted and published porcine model, in which the trocars were inserted at an angle of 90°. Effects of trocar type (bladed vs. bladeless) and angle on defect size were analyzed using a mixed model regression analysis.

RESULTS

The bladeless trocars caused statistically significant smaller defects at the fascia than the bladed (23.4 (SD = 16.9) mm2 vs. 41.3 (SD = 14.8) mm2, p < 0.001). The bladeless VersaOne trocar caused the smallest defect of 16.0 (SD = 6.1) mm2. The bladed VersaOne trocar caused the largest defect of 47.7 (SD = 10.5) mm2. The defect size of the trocars used at a 45° angle averaged 30.5 (SD = 18.3) mm2. The defect size of trocars used at a 90° angle was significantly larger, averaging 58.3 (SD = 20.2) mm2 (p = 0.007).

CONCLUSION

When conical 12-mm trocars are inserted at a 45° angle, especially bladeless ones, they appear to cause small fascial defects compared with insertion at a 90° angle. This might lead also to a lower rate of trocar hernias. Bladeless trocars might cause smaller fascial defects than bladed trocars.

Intraoperative and Postoperative Outcomes of Modified Bidirectional Intra-Umbilical Incision versus Infra-Umbilical Incision for Direct Trocar Insertion in Gynaecological Laparoscopy: A randomised controlled trial

Objectives

This study aimed to describe a modified, curved, deep, bidirectional, intra-umbilical, vertical incision for primary trocar insertion and prospectively compare its intraoperative and postoperative outcomes with an infra-umbilical incision in gynaecologic laparoscopy.

Methods

Between August 2019 and March 2021, 110 patients subjected to the direct trocar insertion technique for laparoscopic intervention were classified into two groups. Group A comprised 55 cases of infra-umbilical incision, whereas group B comprised 55 cases of a modified, curved, longitudinal, deep, bidirectional, intra-umbilical incision. Afterwards, intraoperative and postoperative assessments were performed.

Results

The increase in the numbers of parity, gravidity and previous caesarean sections was found to be statistically significant; a smaller number of infertility complaints were observed in group B. Similarly, group B expressed a statistically significant less peri-trocar CO2 leakage (46 [83.6%] patients versus 28 [50.9%] patients) and more tightness of the primary portal entry (45 [81.8%] patients versus 30 [54.5%] patients) when compared to group A throughout the whole operation. After a one-month follow-up, a statistically significant (P = 0.029) decrease in the Observer Scar Assessment Scale and Patient Scar Assessment Scale scores in group B (10.4 ± 4.2 and 11.8 ± 4.3, respectively), demonstrating better cosmoses when compared to group A (13.3 ± 5.7 and 16.0 ± 6.8, respectively).

Conclusion

Performing a modified, curved, deep, bidirectional, intra-umbilical, vertical incision for the insertion of a primary laparoscopic trocar (i.e. Darwish laparoscopic entry) is a simple and fast step that results in the elimination of intraoperative gas leakage and trocar slippage without the need for any additional sutures. Aesthetically, it results in a better scar with satisfactory cosmoses when compared to an infra-umbilical incision.

Investigation of the Effect of Puncture Order and Position on the Difficulty of Lower and Middle Abdominal Port Placement

Objectives

Port placements at the mid-abdomen (mainstay of robotic surgery [Rob]) appear to be difficult compared to that at lower abdomen (mainstay of conventional laparoscopy [Con-Lap]). We hypothesized that the reason for this may be the difference in port puncture places.

Materials and Methods

We examined how the differences between the place and puncture order of ports affected Con-Lap cases with ports mainly placed in the lower abdomen and Rob cases with ports mainly placed in the middle abdomen. The trocar time was measured from the time when the puncture position and skin incision were determined and initiated, respectively, to the time when the port was punctured and fixed and used as the indicator of difficulty.

Results

In the Con-Lap group analysis, the trocar time of the left lower port was longer (right lower: 77 s, middle lower: 117.5 s, and left lower: 138 s, P < 0.0001). In the Rob group analysis, the trocar time of the left most port was significantly longer (right-most: 89.0 s, right-middle: 92.5 s, left-middle: 121.0 s, and left-most: 197.0 s; P < 0.0001). In addition, the total trocar time was significantly longer in the first puncture at the right-middle port in the Rob group (right-most first: 8.4 min, right-middle first: 12.4 min, and left-middle first: 8.5 min, P = 0.0063).

Conclusion

In the mid-abdomen port placement, mainstay of Rob cases, the puncture order, and port site have a significant impact on the difficulty of the procedure. It is preferable to avoid initially puncturing the right-middle port in case of the Rob.

Bladed and bladeless conical trocars do not differ in terms of caused fascial defect size in a Porcine Model

INTRODUCTION

Trocar insertion during laparoscopy may lead to complications such as bleeding, bowel puncture and fascial defects with subsequent trocar site hernias. It is under discussion whether there is a difference in the extent of the trauma and thus in the size of the fascia defect between blunt and sharp trocars. But the level of evidence is low. Hence, we performed a Porcine Model.

METHODS

A total of five euthanized female pigs were operated on. The average weight of the animals was 37.85 (Standard deviation SD 1.68) kg. All pigs were aged 90 ± 5 days. In alternating order five different conical 12-mm trocars (3 × bladeless, 2 × bladed) on each side 4 cm lateral of the mammary ridge were placed. One surgeon performed the insertions after conducting a pneumoperitoneum with 12 mmHg using a Verres' needle. The trocars were removed after 60 min. Subsequently, photo imaging took place. Using the GSA Image Analyser (v3.9.6) the respective abdominal wall defect size was measured.

RESULTS

The mean fascial defect size was 58.3 (SD 20.2) mm2. Bladed and bladeless trocars did not significant differ in terms of caused fascial defect size [bladed, 56.6 (SD 20) mm2 vs. bladeless, 59.5 (SD 20.6) mm2, p = 0.7]. Without significance the insertion of bladeless trocars led to the largest (Kii Fios™ First entry, APPLIEDMEDICAL©, 69.3 mm2) and smallest defect size (VersaOne™ (COVIDIEN©, 54.1 mm2).

CONCLUSION

Bladed and bladeless conical 12-mm trocars do not differ in terms of caused fascial defect size in the Porcine Model at hand. The occurrence of a trocar site hernia might be largely independent from trocar design.