Keywords
gastroschisis - omphalocele - vacuum-assisted closure - VAC - negative-pressure wound
therapy
New Insights and the Importance for the Pediatric Surgeon
When silo closure fails, an extremely large gastroschisis can be gradually reduced
with VAC dressings, thereby avoiding the use of synthetic or biological mesh.
Introduction
While mortality of gastroschisis in some low- and middle-income countries remains
as high as 100%, in developed countries, gastroschisis mortality is an extremely rare
occurrence given access to skilled neonatal and surgical care, including ventilator
support and total parenteral nutrition. However, complex gastroschisis, whether it
is defined by gastrointestinal issues or abdominal wall factors, behaves as a disease
process with much worse prognosis.[1]
Despite improvements in survival, gastroschisis closure remains challenging, particularly
when the fascial defect is large, eviscerated contents are substantial, medical status
is precarious, or abdominal domain is lost.
Negative-pressure wound therapy (NPWT), including vacuum-assisted closure (VAC), has
been used in children since the 1990s for other challenging wounds to promote the
formation of granulation tissue, reduce edema, remove infection, and control fluid
losses.[2]
[3] Previous series have described the application of NPWT for gastroschisis following
silo placement after the eviscerated bowel is consolidated.[2]
[4]
[5] We herein report the first case where VAC therapy was used to reduce a significantly
matted mass of eviscerated bowel in an infant with gastroschisis.
Case Report
A boy with gastroschisis was born at 355/7 weeks' gestation weighing 2.120 kg, to a G2P1 mother through vaginal delivery. Through
a defect measuring approximately 4 cm in diameter, a substantial portion of matted
abdominal contents was eviscerated, including the stomach, small intestines, and colon.
A spring-loaded 5-cm Silicone Silo Bag was placed at birth (Bentec Medical, Woodland,
California, United States) and was eventually upsized to a 7.5-cm Silicone Silo Bag.
By day of life (DOL) 22, minimal visceral contents had been reduced, and the silo
was difficult to maintain due to the large size of the fascial defect and loss of
abdominal domain. A bespoke VAC dressing was constructed as follows: Whitefoam and
GranuFoam (KCI Medical, San Antonio, Texas, United States) dressings were cut to half
their thickness, fashioned in the shape of a cup by sewing strips together, and placed
over the eviscerated bowel. Strips of adhesive drapes were used to secure the dressing,
circumferentially wrapping the infant. After puncturing the drape, a SensaT.R.A.C.
Pad (KCI Medical) was placed over the dressing, connected to a VAC therapy unit, and
placed to negative pressure that ranged between 25 and 75 mm Hg ([Fig. 1]).
Fig. 1 Initial vacuum-assisted closure dressing on day of life 22.
Endotracheal intubation was necessary for biweekly dressing changes until the viscera
were consolidated ([Fig. 2]). Then Mepitel (Mölnlycke Health Care, Gothenburg, Sweden) was placed over the viscera
prior to Whitefoam and GranuFoam dressings ([Fig. 3]). By DOL 50, the abdominal contents were completely reduced, and VAC therapy was
discontinued. Mepitel was placed until the wound was closed ([Fig. 4]).
Fig. 2 Gastroschisis on day of life 29, 7 days after vacuum-assisted closure dressing was
placed, showing consolidation of herniated abdominal contents.
Fig. 3 Gastroschisis on day of life 39, 17 days after vacuum-assisted closure dressing was
placed, showing dressing materials and nearly complete reduction of herniated abdominal
contents.
Fig. 4 Gastroschisis on day of life 78, showing wound contraction.
Feeds were commenced on DOL 57 and increased to goal by DOL 86. The baby was discharged
home on DOL 115. While initially anemic with cholestasis, by follow-up at 13 months,
both had resolved, and his weight was at the 50th percentile for his age. At that
point, he was discharged from the clinic and lost to further follow-up. At follow-up
clinic visits, the skin had completely epithelialized. An incisional hernia was not
noted, although it is presumed that one was present.
Discussion
Gastroschisis closure has challenged pediatric surgeons for decades. Standard of care
for many years entailed immediate primary closure at birth, which resulted in respiratory
compromise, abdominal compartment syndrome, bowel ischemia, decreased lower extremity
perfusion, anuria, and need for vigorous fluid resuscitation to maintain blood pressure.[6] Occasionally, in challenging cases, silicone sheeting or other plastic materials
such as intravenous bags were sewn to the edges of the fascia or the skin to create
temporary silos until the viscera could be gradually reduced.[7]
[8]
[9]
[10] Some used pneumatic pressure or wringer clamps to reduce the viscera within the
silos.[11]
[12] With time, however, the fascial defect typically grew larger, and sutures caused
the fascia to lose its integrity, making subsequent closure more difficult. In 1995,
the introduction of spring-loaded Silicone Silo Bags that could be easily placed at
the bedside made delayed closure more convenient, and primary reduction was reserved
for newborns whose abdominal contents could be reduced without significant physiological
consequences.[13]
[14]
[15] In some resource-poor countries, locally sourced female condoms have been used when
spring-loaded silicone silos are not available.[16]
Despite these advances, in patients with large fascial defects and loss of abdominal
domain, use of spring-loaded silos has been unsuccessful in reducing the gastroschisis.
At various times, surgeons have used muscle or skin flaps,[17]
[18] skin grafts,[19] synthetic mesh,[20] biological mesh,[21] amniotic grafts,[22] and pericardial patches[23] to achieve visceral coverage and reduce fluid and heat losses. Skin does not readily
cover many of these materials, however, and often mesh needs to be removed[7]
[17]
[20]
[24] or leads to recurrence.[21]
More recently, sutureless closure of gastroschisis has incorporated the umbilical
cord as a biological dressing for primary repair or delayed closure after silo placement.[25]
[26] After the cord sloughs, VAC dressings are often used to cover the exposed viscera
until the wound is epithelialized.[2]
[4]
[5] Until the successful closure in our patient, however, there have been no reports
of the use of VAC dressings for primary coverage in gastroschisis that has not yet
been reduced. Although our patient did need intubation for the first few dressing
changes, once the bowel was consolidated, the VAC dressing could be applied without
sedation. Feeds were commenced once the abdomen was closed, and cholestatic liver
changes resolved after 13 months.
We do note that our patient's initial management with the silo bag might have made
eventual reduction more difficult. Although we generally use the smallest silo bag
possible in order not to enlarge the fascial defect, our patient's defect was initially
relatively large, and therefore we had no choice than to use a 5-cm silo bag. Upsizing
the silo bag made the fascial defect even larger, and in retrospect, were we to encounter
the same problem again, we would opt to commence VAC dressings sooner.
We conclude that VAC dressings can be used to aid gradual reduction of extremely large
gastroschisis anomalies, particularly in medically fragile infants, without the need
for synthetic or biological mesh.
