Evaluation of the positioning of the tip of the Veress needle during creation of closed pneumoperitoneum in pigs.
OBJECTIVE
Erroneous punctures and insufflations are frequent with the use of the Veress needle. Mistaken injections of gas in the preperitoneal space are not rare. The purpose of this research is to evaluate the correct positioning of the tip of the needle during creation of pneumoperitoneum.


METHODS
The needle was inserted into the peritoneal cavity. Tests to assess the positioning of the needle tip were carried out. Pressure, flow rate and volume were periodically recorded and the needle was removed, being immediately reinserted into the right hypochondrium and placed in the preperitoneal space.


RESULTS
The liquid flow test was always positive in the peritoneal cavity. No resistance to saline injection into the peritoneal cavity was observed, but increased resistance to saline injection into the preperitoneal space was observed in 45.5% of the cases. Some saline was recovered in 63.5% of the cases in the peritoneal cavity, and in 54.5% in the preperitoneal space. Saline drop test was positive in 66.6% of the cases in the peritoneal cavity and in 45.5% in the preperitoneal space. In the peritoneal cavity, initial pressure lower than 5 mm Hg was observed, and this pressure gradually increased during 123 seconds until reaching 15 mm Hg. In the preperitoneal space, initial pressure was 15 mm Hg.


CONCLUSIONS
Aspiration, liquid flow and saline drop tests are important, whereas recovery test is inconclusive. Initial pressure of approximately 5 mm Hg indicates that the tip of the needle is in the peritoneal cavity. The peritoneal cavity should hold ten times as much volume of gas as the preperitoneal space. The increase in pressure and volume in the peritoneal cavity can be predicted by statistics.
Center of Minimally Invasive Surgery, Division of Operative Technique and Experimental Surgery, Department of Surgery, Federal University of São Paulo, São Paulo, Brazil. jozevedo.dcir@epm.br
João Luiz Moreira Coutinho
JL
Azevedo
Rodrigo Santa Cruz
RS
Guindalini
Albino Augusto
AA
Sorbello
Cássio Edvan Paulino da
CE
Silva
Otávio Cansanção
OC
Azevedo
Gilmara da Silva
Gda S
Aguiar
Francisco Julimar Correia de
FJ
Menezes
Aline
A
Delorenzo
Rubens Campana
RC
Pasqualin
Fábio Okutani
FO
Kozu
D000818:Animals; D004195:Disease Models, Animal; D005260:Female; D010535:Laparoscopy / Q000379:methods* / Q000592:standards; D008297:Male; D009339:Needles; D011028:Pneumoperitoneum, Artificial / Q000295:instrumentation* / Q000379:methods; D011677:Punctures / Q000379:methods* / Q000592:standards; D012680:Sensitivity and Specificity; D013552:Swine