Laparoscopic Closure of the Nephrosplenic Space for Prevention of Recurrent Nephrosplenic Entrapment of the Ascending Colon in the Standing Horse

numerous factors possibly present to activate the zymogen form of MMP-2 and -9 (i.e. cytokines, bacterial products, gut amines, ischemia/reperfusion), many investigations have only found the MMPs present in the inactive/zymogen form. Adding further question to the role MMPs play in laminar breakdown, a 2009 paper (Loftus et al, Vet Immunol Immunopathol, 2009) reports that both MMPs-2 and -9 are not present in the active form in clinical cases of laminitis due to either a lack of activation/cleavage of the zymogen, or because of interaction of MMPs with inhibitors such as TIMPs. Thus, the presence of the MMPs-2 and -9 does not necessarily mean that they are playing an active role in the disease process. Recent work on other matrix proteases, including MMP-14 and ADAM TS-4 (breaks down matrix proteoglycans), indicates their up-regulation in laminar tissue during the early stages of laminitis; thus, it certainly possibly that other matrix proteases may be involved in the disease process. 

The laparoscopic technique was first described by Marien et al, Vet Surg. 2001 Nov- Dec;30(6):559-63, but some technique modifications have been reported since (Rocken et al, Vet Surg 2005, Fartsvet et al, Vet Surg 2005). Recently, Epstein et al, Vet Surg 2006 described the laparoscopic obliteration of the nephrosplenic space using a polypropylene mesh. 

Over the years we also made some modifications to the original described technique and the following points are important:

• Always check pre operatively is the left colon is not displaced and located between the spleen and the left abdominal wall. This is more often the case in horses with recurrence of LDDLC without causing clinical symptoms of abdominal discomfort. Perform an ultra sound examination if in doubt. One has to be 100% sure there is no left colon between spleen and left abdominal wall to prevent accidentally puncturing the colon when introducing the first trocar.

• The surgery is performed on the standing horse without CO2 insufflation.

• We do not routinely use phenylephrine intravenously pre- or per operatively to contract the spleen.

• The laparoscopic portal is placed between the 17th and the 18th rib. The two instrument portals are located in the paralumbar fossae, halfway between the 18th rib and the tuber coxae.

• We use a 25 mm diameter and 15 cm long canula to facilitate the entrance of an 8 metric polyglactin 910 suture (vicryl), 1.5 m long and with a 48 mm swaged on 1⁄2 circle needle. The use of a large needle makes it easier to take larger bites (2-3 cm) through the nefrosplenic ligament and dorsal spleen reducing the amount of intra-abdominal manipulations while suturing.

• A 45 cm long needle holder is used to be able to start the closure as far proximal as possible. Make sure the needle holder is strong enough to hold a large 48 mm needle.

• A continuous suture pattern is used and closure ends at the caudal free border of the nephrosplenic ligament with an extra corporeal knot using a knot pusher.

• The horses are given 6 weeks rest and walking exercise before resuming normal work. [...]