Objective—To compare the effects of 2 approaches and 2 injection volumes on diffusion of mepivacaine hydrochloride for local analgesia of the deep branch of the lateral plantar nerve (DBLPN) in horses.
Animals—16 adult horses.
Procedures—Either 2 mL (low volume) or 8 mL (high volume) of mepivacaine hydrochloride-iohexol (50:50 mixture) was injected by means of 1 of 2 techniques to produce analgesia of the DBLPN. For technique 1, the needle was inserted 15 mm distal to the head of the fourth metatarsal bone and directed perpendicular to the limb. For technique 2, the needle was inserted 20 mm distal to the head of the fourth metatarsal bone and was directed in a proximodorsal direction. Lateromedial radiographs were obtained before and 5, 15, 30, and 60 minutes after injection. Radiographs were evaluated to determine the proximal and distal extent of diffusion of the contrast solution and presumably anesthetic agent and whether contrast agent appeared to be present in the tarsal sheath or tarsometatarsal joint.
Results—A high degree of variability in contrast solution diffusion was noted among injections. High-volume injections diffused significantly further proximally and distally than did low-volume injections. Contrast agent was documented within the tarsal sheath in 5 of 32 (16%) injections and within the tarsometatarsal joint in 2 of 32 (6%) injections. No significant difference was found for risk of inadvertent tarsal sheath or tarsometatarsal joint injection between the 2 techniques or the 2 volumes of anesthetic used. Mepivacaine diffused significantly further distally with technique 1 than with technique 2 but diffused significantly further proximally with technique 2 than with technique 1. For both techniques, diffusion in the distal but not the proximal direction significantly increased over time.
Conclusions and Clinical Relevance—Results indicated that the proximal and distal diffusion of the mepivacaine-iohexol solution was quite variable following either DBLPN nerve block technique.
Objective—To compare a double-layer inverting anastomosis
with a single-layer appositional anastomosis,
coated with either 1% sodium carboxymethylcellulose
(SCMC) or 0.4% sodium hyaluronate (HA) solutions,
in the small intestine of horses with respect to
anastomotic healing and adhesion formation.
Animals—18 adult horses.
Procedure—Midline celiotomy and end-to-end jejunal
anastomoses were performed. In control group horses
(n = 6), a double-layer inverting anastomosis coated
with sterile lactated Ringer's solution was performed.
In treatment group horses, a single-layer
appositional anastomosis was performed that was
coated with 1% carboxymethylcellulose solution
(SAA + SCMC group horses, 6) or 0.4% hyaluronate
solution (SAA + HA group horses, 6). An additional
500 mL of the respective treatment solution was
applied to the jejunal serosal surface, and 2 jejunal
serosal abrasion sites were created. Horses were
euthanatized 10 days after surgery. Anastomoses and
abdominal adhesions were evaluated grossly.
Anastomotic healing was evaluated on the basis of
bursting wall tension.
Results—Bursting wall tension was significantly
greater in SAA + SCMC group horses, compared with
control group horses. All intestinal segments failed at
a point distant to the anastomosis. Significantly fewer
adhesions were found at the abrasion sites of SAA +
HA group horses, compared with control group horses.
No differences were found in adhesion formation
at the anastomotic sites among groups.
Conclusions and Clinical Relevance—Coating a single-
layer appositional jejunal anastomosis with SCMC
or HA solutions does not adversely affect anastomotic
healing. Application of 0.4% HA solution to the
serosal surface of the jejunum significantly decreases
the incidence of experimentally induced intra-abdominal
adhesion formation in horses. ( Am J Vet Res 2004;65:637–643)
Objective—To compare the outcomes of doublelayer
inverting anastomosis (DIA), single-layer anastomosis
(SLA), and single-layer anastomosis combined
with a hyaluronate membrane (SLA+HA-membrane)
with respect to stomal diameter, adhesion formation,
surgery time, and anastomotic healing in horses.
Animals—18 adult horses.
Procedure—Midline celiotomy and end-to-end anastomoses
were performed. In control horses (n = 6),
DIA was performed; in treated horses, SLA was performed
(6) or SLA+HA-membrane was performed (6).
Horses were euthanatized 21 days after surgery.
Abdominal adhesions were evaluated grossly and histologically.
Stomal diameters were measured ultrasonographically
and compared with adjacent luminal
diameters. Anastomotic healing was evaluated histologically
for fibrosis and inflammation, tissue alignment,
and inversion. Surgery times were recorded for
the anastomotic procedure and compared among
Results—There were significantly more adhesions in
the SLA group, compared with the DIA and SLA+HAmembrane
groups. Reduction in stomal diameters in
the DIA group was significantly greater than the SLA
and SLA+HA-membrane groups. Surgery times for
the DIA group were significantly greater than the SLA
and SLA+HA-membrane groups. Histologic findings
of fibrosis, inflammation, and mucosal healing were
similar among groups. There was significant tissue
inversion in the DIA group, compared with the 2 treatment
groups. Tissue alignment was not different
Conclusions and Clinical Relevance—Use of a
SLA+HA-membrane was an effective small intestinal
anastomotic technique. This technique was faster to
perform and resulted in a larger stomal diameter,
compared with the DIA technique and significantly
fewer perianastomotic adhesions, compared with the
SLA technique. (Am J Vet Res 2001;62:1314–1319)