COMPARISON OF EFFICACY AND SAFETY BETWEEN SUBLAY AND ONLAY MESH REPAIR FOR PARA-UMBILICAL HERNIA

INTRODUCTION
Para-umbilical hernia is a protrusion of the intestines
or gut through a weak point of the muscles
or ligaments in the linea alba near the navel1,either
superiorly or inferiorly2. This form of hernia along with
incisional hernias constitutes about 85% of the overall
ventral abdominal hernias1.
Repair of para-umbilical hernia was earlier performed
by the suture technique (Keel or Mayo’s) but it
has a high recurrence rate - almost 19% - 54%3. This
failure of primary suture is the most dreaded complication
with immense physiological, psychological and
financial consequences. Thus it has been replaced with
Mesh repair which is recognized as a Gold standard for
para-umbilical hernia repair, having a very low recurrence
rate compared to simple suture procedure4. A
number of surgical mesh repair techniques and types
are available. These include onlay, inlay and sublay
procedures. Studies have concluded that the Inlay
procedure whereby there is an increased chance of
bowel – mesh contact can be associated with serious
complications such as chronic pain, intestinal obstruction,
enterocutaneous fistula and infertility.5 The choice
these days largely rests between onlay and sublay procedures.
In the sublay technique (subfascial prosthetic
repair or the Rives technique) the mesh is placed in the
pre-peritoneal plane created between the rectus muscle
and posterior rectus sheath. The mesh extends well
beyond the under edges of the defect (3-4cm) and is
not merely sewn to the hernia edges. In this technique
peritoneum protect the abdominal viscera intestine from
injury from the mesh and avoid intestinal adhesions.6
As opposed to this in the onlay technique (prefascial
prosthetic repair or the Chevrel technique)closure of
the hernia defect is done with non-absorbable sutures
followed by placement of mesh superficial to the external
fascia also using non-absorbable sutures7.
The complications observed after mesh repair are
Seroma, Hematoma, Infection, Skin Necrosis, wound
dehiscence, Sinus formation, Pulmonary and GIT
complications2. However the frequencies of these complications
vary in patients having different techniques
of mesh repair. In a study by Jat et al comparing the
sublay and inlay techniques for repair of ventral hernias
clearly concluded that sublay repair is safer and more
effective form of ventral hernia repair with fewer complications
than in inlay repair. In another study by MR
Memon quoting results of Stoppassublay repair, wound
infection was found in 6.5% and seroma formation in
2.5%. Mortality was 0.5%. No recurrence was seen
during the follow-up period of 2 years. No septic mesh
was removed in the series.3
Although the sublay repair is a favored approach
by many surgeons, there are still proponents of the onlay
repair describing it as a simple and effective repair
operation with a short learning period for the surgeon.
It has also been observed that this is a safe procedure
in terms of complications (13%) and recurrence rates
(15%)4. Another study by Weber G has shown that in the
large hernia group, onlay mesh reconstruction provided
significantly better results than sublay reconstruction ,
with a recurrence rate much lower in onlay group (12%)
vs the sublay group (20%)8.
Another study by Rajesh Godrsetal comparing
onlay and sublay repair concluded that onlay mesh
placement is effective (no recurrence), quick (mean total
time for surgery 49.35 ± 8.29 minutes in onlay group
compared to sublay group with a time of 63.15 ± 15.0
minutes) and associated with a shorter convalescense
time (mean hospital stay in sublay was 6.8 ± 1.50
days whereas it was 4.6 ± 1.30 in onlaygroup9.
While the controversy regards the best possible
procedure for mesh placement to repair ventral hernias,
still rages there is a growing consensus that the choice
lies between sublay and onlay procedures. Both these
approaches have their advocates with conflicting views
on the safety, efficacy, complications and technical ease
with which they are performed. Studies and trials are
actively being pursued to define the better of the two
procedures. With this perspective in mind, the following
study had been planned to compare the efficacy and
safety of onlay and sublay mesh repairs of para-umbilical
hernia in our local population