Despite the fact that
several investigators advocate surgery in all patients with a diagnosis of MGM
regardless of symptoms or age, there is a general agreement that the surgical
intervention is the treatment of choice only for complicated MGM cases [12,16].
In these cases, MGM patients with acute onset of symptoms may already have
haemodynamic instability with sepsis from bowel ischaemia or perforation or
complete refractory obstruction, or they are in high risk to have it in the
next hours [10,17,18,22]. What is primarily required in each emergent case is a
quick clinical assessment and a laboratory work-up, and, for the unstable
patient, immediate simultaneous intense fluid resuscitation and haemodynamic
support to correct dehydration and electrolyte/metabolic disturbances
(acidosis), nasogastric decompression and administration of broad-spectrum
antibiotics [4,10,16,23]. The operation is performed openly due to the existent
significant bowel distension, the altered anatomy, and concern for potential
bowel injury with a laparoscopic approach [12,19,26].
However, in the acute setting, surgeons are occasionally confronted with
underlying pathology with limited or lacking preoperative information,
or unexpected findings,
and are forced to use a treatment option with little
evidence [25] . This is
particularly true for complicated MGM cases.
Treatment
recommendations for neonates, infants and young children
The standard of care for
neonates and infants suffering from symptomatic or complicated MGM (duodenal
obstruction, MG volvulus) is the Ladd’s surgical procedure, originally proposed
by William Ladd on 1936 [3-7,16,23,31]. In the vast majority of cases,
characterized by absence of bowel necrosis, it involves: (i) counter-clockwise
detorsion of the volvulised bowel (if MG
volvulus is the case) with full inspection of the mesenteric root; (ii)
division of Ladd’s bands and other congenital peritoneal adhesions (especially,
around the SMA) to relieve obstruction and straighten the duodenum along the
right abdominal gutter; (iii) broadening of the narrow mesenteric root, and
re-orientation of the small bowel on the right hemiabdomen and the colon on the
left side; and (iv) prophylactic appendectomy (usually), to prevent future
diagnostic confusion in the setting of acute appendicitis [3-6,13,14,23,31].
The rare case of intrauterine fetal MG volvulus mandates rapid and
multidisciplinary management including double surgical intervention, an
emergent caesarian section on the mother for delivering of the neonate, and an
emergent laparotomy on the neonate for detorsion of its twisted bowel and
prevention of intestinal necrosis [6,7,23]. Conclusively, the classic Ladd’s
technique, which is not a true correction procedure, aims primarily to rescue
newborns with complicated MGM [31]. In the absence of severe associated
anomalies, the isolated MG volvulus has a favourable prognosis postoperatively
[6].
The management of
children with asymptomatic or minimally symptomatic or incidental MGM remains
controversial [12,14,32]. The potential to develop sudden onset of acute
complications in asymptomatic patients always exists at any age, thus,
proponents of a prophylactic Ladd’s procedure site that the perioperative risk
associated with an elective surgery is far lower when compared to an emergent
one [12]. However, the traditional thought is that the asymptomatic MGM
diagnosed after two years of life poses minimal risk. Avoiding surgery in older
asymptomatic children and adults is also justified by the dramatically
declining risk of presenting patients with volvulus with advancing age [12].
Moreover, it has been reported that, correcting asymptomatic MGM beyond the age
of 20 years is ineffective and probably harmful [4]. The 2015 American
Pediatric Surgical Association (APSA) outcomes and evidence-based practice
committee concluded that there is minimal evidence (Level 4) and recommendation
(Grade D) to support screening, and recommended observation for older children
with asymptomatic MGM [32]. An issue of concern is the recurrence of MG
volvulus after the index surgery [5,9,26]. Many investigators suggest that the
recurrence rate among children is low, and a pexy of bowels may constitute an
unnecessary addition [14]. The 1980’s Stauffer’s series [33] with 77 children,
who had undergone a Ladd’s procedure with or without pexy, showed a trend for
less reoperation in the group with pexy, but no significant difference in the
recurrence rate between the two groups. However, the recurrence rate among
patients who underwent Ladd’s procedure alone in the adulthood is much higher
than the one reported in children, estimated in some series as high as 16% [9]
or even 18% [8]. Advocators of a complementary fixation during the index
surgery or when treating recurrence have used various techniques, such as
suturing of the posterior duodenum to the right renal fascia (duodenopexy),
anchoring the caecum to the left abdominal wall (caecopexy), or some fixation
of the small bowel or its mesentery (enteropexy, mesentericopexy )
[14,19,26,31].
Treatment
recommendations for emergent patients beyond infancy until adulthood
In the emergency setting
for older ages, the surgical bowel detorsion alone is not an option, since it
is associated with a high risk of recurrence (20-75% in cases of right
colon/caecal volvulus), besides the fact that bowel excision for ischaemic
necrosis and correction of coexistent pathology are inevitably required
[11,16]. Instead, some elements of the Ladd’s method should complete the required
operation, i.e., the division of Ladd’s and thick peritoneal bands, the taken
down of the “ligament” of Treitz with the creation of a “Treitz neo-ligament”,
and the straightening of duodenum to the right [5,11,15,19,23,31]. The type of
the surgical operation in complicated cases is determined by the individualized
variant of the developmental defect, the intraoperative situation of the bowel,
and the patient’s status for surgery [8,10,18,21]. It is crucial for the
operating surgeon to recognize associated abdominal vascular and other
coexistent anomalies, and tailor the surgery accordingly [4,10,31]. However,
there remains much debate regarding the proper management for specific forms of
primary MG volvulus in these ages [19,31].
An issue of concern is
the place of colonoscopic devolvulation in complicated cases with RCV
obstruction that is associated with non-gangrenous colon. In contrast to its
application in sigmoid volvulus cases, this non-operative relief method is
rarely used in complicated MGM cases, since it is rarely successful and
subsequent revolvulation often occurs, leading to a high risk of perforation
[18,29,34]. However, it could sometimes convert an emergent procedure in a
debilitated and poorly prepared patient to a semi-elective one, providing
temporary mechanical detorsion and decompression of the bowel [18,34].
For the emergent stable
patient, beyond the early period of life, who responds well to resuscitation,
who has no risk factors, and who has bowel ischaemic necrosis or perforation or
not, the optimal surgical management entails open right hemicolectomy with
primary ileotransverse anastomosis for MG volvulus, and the rarest case of ICI
on underlying MGM [10,18,21,34]. Prerequisites for this type of surgery are
achieving viable and healthy bowel ends and the absence of adverse factors in
anastomotic healing (i.e., malnutrition, steroid use, bowel edema) [10,18,22].
If the patient is at high risk for anastomotic leak or was preoperatively
assessed with poor rectal tone or incontinent sphinchter (elderly), then
resection with creation of ileostomy remains a viable option [18,22,31].
Extended large bowel resection or, instead, segmental bowel resection and
colopexy have also been reported in specific cases [10]. Non-resectional approaches
in the setting of viable colon after devolvulation, such as the colopexy or
combination of pexy and caecostomy, have been used as suboptimal surgical
options but life saving measures on debilitated-malnutritioned patients;
reportedly, detorsion alone is associated with recurrence rate as high as 75%,
and detorsion with colopexy is associated with a recurrence rate up to 40% and
a mortality up to 18% [16,18,22,31,33]. Notably, the presence or coexistence of
ICI mandates that the resection should achieve negative oncological bowel
margins [17,18,21].
On the other hand, for
the emergent unstable patient with sepsis from bowel ischaemia or perforation,
or complete obstruction (strangulation), characterized by one or more of
metabolic acidosis, hypoxia, sustained hypotension and coagulopathy, there is
no time for full resuscitation and optimization [18]. Reversal of haemodynamic
instability will not occur unless bowel obstruction has been resolved. This
patient in extremis should undergo simultaneous resuscitation and transfer to
the operating room [10,18,34]. Damage control surgery is the option, involving
rapid stapled in situ resection of the volvulised (rarely, intussuscepted)
gangrenous bowel segments and mesentery (i.e., right hemicolectomy), control of
spillage and lavage/debridement, proximal bowel diversion (usually), and
temporary abdominal closure [10,13,18,34]. Intentionally, conserving the
intestines in case of uncertainty is considered as a valid option instead of
extended intestinal resection, especially in young patients [4]. This is a very
important issue.
The choice of a technique
of temporary closure in the case of significant bowel distension or when bowel
of questionable viability was left in situ, is another issue of concern. For
this case, particularly in adults, a laparostomy dressing, an absorbable mesh
(i.e.,vicryl mesh) or a BOGOTA bag may be applied [4,13]. These patients are
better closely attended in the surgical intensive care unit, so as to promptly
recognize and treat every exacerbation of metabolic /lactic acidosis, decrease
in urinary output and worsening of laboratory examinations, indicating tissue
reperfusion injury or that the bowel segment in uncertainty has not recovered
or is necrotizing [4]. Based on the degree of response to resuscitation after
index surgery, a return to the operating room within 24-48 hours for re-look
(s) is required [18,34]. Bowel reconstruction in cases with healthy bowel, or,
instead, complementary excision when bowel necrosis is evident, should accordingly
be performed [4,13].
The postoperative
complications, minor in most of the cases, are associated with the present
developmental anomalies, the type of surgery performed, and the patient’s
physical status. They include wound infection, adhesive ileus, delayed gastric
emptying, and recurrence [8]. Unfortunately, complicated MGM that is associated
with excessive bowel necrosis leads to extended bowel resection, either during
the index surgery or during re-operation; patients with “short bowel syndrome”
require close and continuous caring for malnutrition (in need of lifelong
parenteral nutrition), electrolyte disturbances, immune deficiency, and even
sepsis [23].
In the emergency setting,
the role of laparoscopic intervention for complicated MGM remains limited.
Theoretically, in symptomatic but stable patients with absence of bowel
necrosis or excessive bowel distension, the Ladd’s procedure can be performed
laparoscopically, gaining less postoperative pain and shorter time to full
enteral feeding and hospital stay. In practice, the physical status of these
few patients undergoing laparoscopy for MGM is markedly better than those who
undergo laparotomy; nonetheless, up to one third of the laparoscopic procedures
are eventually converted to open surgeries [4,12,16,35,36]. There is also
evidence of an increased risk of volvulus recurrence with the laparoscopic
approach in children due to the poor formation of post-operative adhesions
[12,36]. However, laparoscopy for MGM with bowel obstruction has very rarely
been reported, probably due to perceived difficulties with the use of
laparoscopic tools and the rarity of this condition [15,34]. Prospective
randomized studies with long follow-up are required to evaluate the true
efficacy of the laparoscopic approach.