Keywords ruptured abdominal aortic aneurysm - abdominal compartment syndrome - intra-abdominal
pressure - open abdomen
Introduction
Abdominal compartment syndrome (ACS) is a common complication after ruptured abdominal
aortic aneurysm (rAAA) repair, which may have a major pathophysiological impact and
significantly affect prognosis. Indeed, ACS has been reported to complicate rAAA repair
in up to 20% of cases.[1 ]
[2 ] This is more pronounced among patients treated by open surgery compared to endovascular
aneurysm repair (EVAR).[2 ] The pathophysiological background which can lead to the development of ACS may include
hemorrhage, intestinal ischemia, or generalized bowel edema, but, irrespective of
the cause, this condition has been identified as a significant predictor of mortality.[3 ] Indeed, Ersryd et al[4 ] suggest that ACS almost doubles postoperative mortality, which is 42 and 23% among
those with and without ACS, respectively. Similar results have been reported by Rubenstein
et al,[2 ] with respective mortality rates of 62 and 33%.
Upon diagnosis of ACS, decompression laparotomy is indicated to relieve intra-abdominal
pressure (IAP) and prevent the ischemia of abdominal organs and its catastrophic consequences.
Indeed, the 2013 World Society of the Abdominal Compartment Syndrome consensus management
statement recommends decompressive laparotomy in cases of overt ACS rather than strategies
that do not use decompressive laparotomy (GRADE 1D strength of recommendation).[5 ] Open abdomen can also be used in a preventive manner during the treatment of high-risk
patients to prevent ACS development. Indeed, an open abdomen during the primary operation
(prevention) has been shown to present favorable results compared to that during a
secondary operation (treatment), with less intestinal ischemia, shorter duration of
open abdomen, and less renal replacement therapy.[6 ] Overall, leaving the abdomen open in a prophylactic manner has been reported in
up to 19% of cases after rAAA treatment, with an average value around 5 to 10%, mainly
in cases with a tense abdomen that was difficult to close.[7 ]
[8 ]
[9 ] Several techniques have been used in patients who require open abdomen treatment,
such as vacuum-assisted wound closure, mesh-mediated fascial traction, dynamic retention
sutures, and the so-called Wittmann patch, which uses a nonpermeable Velcro patch,
thus preventing lateralization but not permitting effective drainage.[7 ]
Skin-only closure of the abdomen after rAAA has been only scarcely reported in the
literature. This technique could prevent ACS development in many cases, at the expense
of a significant proportion of patients being left with a planned ventral hernia and
accompanying complications. In our department, we routinely use skin-only closure
in patients with rAAA repair. In this report, we summarize our experience with this
technique.
Materials and Methods
Study Design and Patient Population
This is a single-center, retrospective descriptive study which included all consecutive
patients treated for ruptured infrarenal or juxtarenal AAA during a 7-year period
(January 2014 to December 2020). Open surgical repair was performed in all cases.
The fact that currently EVAR is not offered for rAAAs at our department is the result
of management logistics not allowing to stock endografts of all sizes onsite, while
at the same time, the geographic isolation of our region from the endograft companies
on mainland Greece results in a delayed acquisition of the endograft of 8 to 20 hours,
depending on the time of day of patient admission. Typically, patients with suspected
rAAA underwent a preoperative computed tomography (CT) scan, after which they were
immediately transferred to the operating theater. A strategy of permissive hypotension
is generally employed during the management of these patients and until definitive
treatment, which according to current guidelines is beneficial for patients with rAAA.[10 ] In general, through a midline incision and transperitoneal access, the aorta was
approached in order to obtain infrarenal aortic control. Suprarenal aortic clamping
through the lesser omentum was only selectively used in case of anatomic constraints
that would make infrarenal clamping challenging, such as proximal disease, significant
angulation, morbid obesity, etc. The use of an aortic occlusion balloon, although
a useful adjunct that can be used in selective cases, has not been used in the current
series. Skin-only closure was routinely (meaning that this was our preferred approach
and our primary treatment strategy) performed during the index operation, with a running
or interrupted suture, while the abdominal fascia was left open to prevent ACS. Primary
fascial closure was only selectively performed in cases deemed very low risk for the
development of this complication (hemodynamically stable patients, with a small retroperitoneal
hematoma and a straightforward surgical repair).
After the initial procedure, patients were transferred to the intensive care unit
(ICU) where they were kept intubated and their clinical condition was reevaluated
daily, to determine whether abdominal fascial closure could be performed. Reevaluation
was based mainly on IAP recordings (at least twice/day using transbladder measurements),
renal function, and acid–base balance. In general, an IAP <12 was required in order
to attempt fascial closure. Moreover, acute kidney failure and the need for renal
replacement therapy were considered a contraindication to definite abdominal closure.
If fascial closure was considered feasible, patients were transferred to the operating
theater where this was performed. Otherwise, in case this was not considered safe,
patients were progressively weaned and extubated and transferred from the ICU to a
regular hospital bed. During the same admission, abdominal fascial closure was in
some cases performed after a maximum of 7 days from the index operation. If this was
not feasible, patients were discharged with a planned ventral hernia repair at a later
time during another admission.
Collection of Data, Definitions, and Endpoints
Demographic information and hemodynamic condition of patients at presentation were
recorded. The Edinburgh Scoring System (ERAS) was used to classify patients according
to their risk of mortality. ERAS is a scoring system which has been suggested for
patients with rAAA because it is strikingly easy to use and has been shown to have
a good correlation with the risk of mortality. ERAS takes into account only three
parameters and assigns 1 to 3 points according to their values. Specifically, 1 point
is assigned if hemoglobin < 9 g/dL, Glasgow Coma Scale <15, or systolic blood pressure
<90 mm Hg, for a total score ranging from 0 to 3. A stepwise increase in ERAS was
linked to a consecutive increase in mortality.[11 ]
Moreover, operative information such as type of incision, type of graft used (i.e.,
tube vs. bifurcated), need for transfusion, intraoperative mortality, and type of
abdominal wound closure were also recorded.
Postoperatively rate of ACS, in-hospital mortality, length of hospitalization, and
rate of definite abdominal closure were recorded. ACS was defined according to the
updated consensus definitions and clinical practice guidelines from the World Society
of the abdominal compartment syndrome published in 2013: sustained IAP >20 mm Hg (with
or without an abdominal perfusion pressure (APP) <60 mm Hg) associated with new organ
dysfunction/failure. The APP is defined as the mean arterial pressure (MAP) minus
the IAP. Additionally, postoperative information such as hernia-related complications
and the need for late hernia repair was also collected through telephone contact with
patients.
Statistical Analysis
Quantitative data are summarized as mean values ± standard deviation if values are
normally distributed and as median (range) if not. Qualitative data are reported as
frequencies as appropriate (count and percentage).
Institutional review board approval was obtained for this study. Patient consent was
obtained from participants.
Results
During the study period, the repair was attempted in 83 rAAA cases. There were 10
additional patients in whom repair was not undertaken because they were deemed too
frail to undergo repair, died before reaching the operating theater, or refused treatment.
Repair was performed with open surgery in every case. All patients had a preoperative
CT scan. Retroperitoneal rupture was recorded in 75 patients, while this was free
intraperitoneal in the remaining 8. The mean age of patients was 72.4 ± 10.5 years,
and the vast majority were male (82:1). Mean systolic blood pressure at the time of
presentation was 105 ± 15 mm Hg. Baseline systolic blood pressure < 90 mm Hg was recorded
in 31 patients. The median ERAS score was 1 (0–3). Baseline characteristics of patients
and perioperative variables are summarized in [Tables 1 ] and [2 ], respectively. Demographic characteristics and comorbidities of patients are those
of a typical AAA cohort with a high rate of male patients >70 years old who smoke.
The 42% rate of cardiac disease may be a low proportion for such a patient group,
which could be due to the strict criteria that have been used to define this variable.
Including, a history of angina, previous myocardial infarction, arrhythmias, cardiac
medication, and other clinical parameters would increase the proportion of patients
with cardiac disease.
Table 1
Summary of baseline demographics and comorbidities
Demographics/Comorbidities
Total (n = 83)
Age[a ]
72.4 ± 10.5 y
Male
82
99%
Hypertension
73
87%
Hyperlipidemia
62
75%
Diabetes mellitus
18
22%
Renal disease[b ]
29
35%
Heart disease[c ]
35
42%
COPD[d ]
38
46%
Smoking
69
83%
AAA maximum diameter[a ]
74 ± 9 mm
Abbreviations: AAA, abdominal aortic aneurysm; COPD, chronic obstructive pulmonary
disease.
a Mean ± standard deviation.
b Glomerular filtration rate < 60 mL/min/1.73 m2
c Documented disease by coronary angiography or systolic or diastolic heart failure
documented by echocardiography or diagnosis by cardiologist.
d Documented diagnosis with forced expiratory volume in 1 second <80% by spirometry
or those taking relative medication.
Table 2
Perioperative variables
Perioperative variables
Total (n = 83)
Retroperitoneal rupture
75
90%
Hemodynamic instability[a ]
31
37%
ERAS score[b ]
1 (0-3)
ERAS score distribution
0: n = 15
1: n = 34
2: n = 19
3: n = 15
Transfusion[b ]
5 (2–19)
ICU stay[b ]
5 (1–24) d
Hospital stay[b ]
13 (8–35) d
Mortality
29
35%
Renal failure[c ]
48
58%
Intestinal ischemia[d ]
19
23%
Acute limb ischemia[e ]
9
11%
Abbreviations: ERAS, Edinburgh Scoring System; ICU, intensive care unit.
a Defined as systolic arterial pressure >90 mm Hg, at initial presentation.
b Median (range).
c Defined as need for temporary or permanent hemodialysis.
d Diagnosed with surgical exploration and requiring bowel resection.
e Mandating a revascularization procedure or a major amputation.
A median of 5 (2–19) units of red blood cells were given intraoperatively. Overall,
37 tube and 46 bifurcated grafts were used. Intraoperative mortality was recorded
in nine cases, presenting with an ERAS score ≥2. Seventy-four patients left the operating
theater alive and skin-only closure was used in 69 cases. In five cases, the rupture
was small with a contained retroperitoneal hematoma, in hemodynamically stable patients
with ERAS score 0, thus providing confidence that the development of ACS was unlikely,
in these patients definitive abdominal closure with a continuous fascial suture was
performed. All patients were transferred into the ICU postoperatively. ACS occurred
in two patients in the skin-only closure group (2 and 4 days after rAAA repair). In
these cases, sutures were removed and the abdomen was left open with a negative-pressure
vacuum system. Both patients died in ICU. No cases of ACS were recorded among the
five cases with primary fascial closure. Among the remaining 67 patients with skin-only
closure, 30 patients experienced an uneventful postoperative course, with values of
IAP <12 and without acute renal failure. In these cases, definite abdominal closure
was performed, after a mean of 4 days from the index operation. All these patients
survived the perioperative period. Among the remaining 37 patients, 18 died, and 19
survived, being discharged from the hospital with a planned ventral hernia. Median
length of stay in ICU was 5 (1–24) days, while median total hospital stay was 13 (8–35)
days. Total perioperative mortality was 34.9% (29/83). The flowchart of the study
population is presented in [Fig. 1 ].
Fig. 1 Flowchart of the study population. ACS, abdominal compartment syndrome; rAAA, ruptured
abdominal aortic aneurysm; VAC, vacuum-assisted closure.
Telephone contact was possible with 39 of 54 patients who were discharged after rAAA
repair. The mean follow-up was 21 months. Among 35 patients with fascial closure,
25 were contacted and did not report any complications related to abdominal wall closure.
Among 19 patients who were discharged with a planned ventral hernia repair, we could
reach 14. Three reported a hernia-related complication and/or significant disability
affecting their daily activities. These patients underwent hernia repair. The remaining
11 patients did not report any significant morbidity related to the hernia and did
not opt for a hernia repair and a secondary abdominal fascial closure.
Discussion
In our single-center experience, routine skin-only closure of the abdominal wound
after rAAA repair was linked to a very low ACS rate of 2.7%, at the expense of 35%
of survivors being discharged with a planned ventral hernia and 21% of those requiring
a ventral hernia repair due to complications. Taking into account that the main objective
of the treatment of rAAA patients is to survive, one would argue that any useful adjunct
at the time of the initial repair should be employed, even at the expense of additional
morbidity or the need for additional operative management in the future. Indeed, with
the approach we describe, only two cases of ACS were recorded among patients who survived
rAAA surgical repair for a total rate of 2.7% (2/74). Notably, both patients died
in the ICU a few days after the initial procedure despite the removal of sutures in
the skin.
The rate of ACS after rAAA repair is variable, ranging from 3.7 to 35%. Ersryd et
al,[3 ] in a recent study from the Swedvasc registry, recorded a 3.7% rate after open surgical
repair (OSR) and 7.5% after EVAR for rAAA. A previous report from the same database
recorded 6.8 and 6.9% ACS rates after OSR and EVAR for rAAA, respectively.[4 ] Contemporary single-center studies suggest much higher rates, such as from Rubenstein
et al,[2 ] who reported a remarkably high ACS rate of 34% after OSR and 21% after EVAR. Mayer
et al[9 ] reported that 20% of patients undergoing rAAA EVAR presented ACS. The reason behind
this large variability in the incidence of ACS after rAAA repair is not clear. One
possible explanation is that some studies do not use strict criteria to define ACS.
Indeed, a systematic review of EVAR for rAAA recorded a pooled ACS rate of 8%, which
increased to 17% when metanalysis was repeated after including only those studies
that clearly defined ACS and 21% when only studies focusing on ACS were selected.[1 ] Clear definitions may be a significant problem, particularly when reporting results
from registries, perhaps explaining the low ACS rates using the Swedvasc database.
Overall, a 20% rate of ACS after rAAA repair would seem a reasonable, pragmatic, approximation.[12 ] The rate of ACS rate that has been found in the present study is much lower than
those typically reported in the literature. Nevertheless, it should be underlined
that even with skin-only abdominal closure, ACS is possible in extreme cases, like
the two patients identified in the current series.
Since ACS has undoubtedly been identified as a possible complication after rAAA repair
which significantly increases risk of mortality, most institutions have developed
strategies for an early diagnosis. Therefore, close monitoring of patients in the
immediate postoperative period, in the ICU setting, with abdominal pressure measurements
several times per day is of paramount importance, in order not only to timely diagnose
ACS but also to prevent it via nonoperative measures.[5 ] In most institutions, the prophylactic open abdomen is only used in a minority of
patients in whom fascial closure is extremely difficult or impossible, probably because
of the various hazards of this approach, such as high costs, exposure of abdominal
viscera and grafts to infection, loss of heat and fluids, need for complex surgery
to cover bowels, and finally to reconstruct the abdominal wall.[12 ] Of course different centers may keep a different threshold for leaving the abdomen
open in a prophylactic manner, and a wide range of relevant rates has been reported
in the literature. An algorithm to ensure timely diagnosis and treatment of ACS in
patients with rAAAs is provided in the recent guidelines of the European Society for
Vascular Surgery. This suggests, at first, conservative management and if this proves
unsuccessful, decompression is indicated.[10 ] We propose an alternative strategy, where the fascial layer is left open routinely,
in an effort to prevent ACS. This would not qualify for the definition of open abdomen
according to the formal statement provided in current guidelines,[5 ] which requires both the abdominal fascia and the skin to be left open. This approach
may represent an attractive alternative, deferring tight abdominal closure for a later
time. The remaining patients are discharged from the hospital, with a planned ventral
hernia. This needs surgical treatment in less than 25% of patients. This abdominal
hernia may cause discomfort or occasionally intestinal obstruction due to adhesions,
but not the severe and potentially lethal complications of a true open abdomen (such
as contamination, fixity, entero-atmospheric fistula, etc.).[7 ] The majority of patients tolerate this condition well. Actually, one could argue
that the routine skin-only closure approach proposed here is the “medio tutissimus
ibis” (the middle course is the safest and best) between fascial closure and open
abdomen for the prevention of ACS. Skin-only closure might also facilitate subsequent
fascial closure by preventing lateralization of the rectus muscles which usually occurs
about 5 to 7 days postoperative and prevents fascial closure with conventional surgical
techniques.
The present findings should be interpreted in the context of the limitations of this
study. The main limitation is the small number of participants and the limited follow-up
period. Secondly, some patients were lost to follow-up, and therefore, their outcome
is uncertain. Thirdly, this report is limited by its observational, retrospective
design, which makes it subject to selection and recall bias. Nevertheless, to our
knowledge this is the first published report to evaluate the results of routine skin-only
closure after rAAA repair, These preliminary results provide encouraging grounds for
further studies to delineate the possible value of this method during treatment of
these marginal patients.
Conclusion
Routine skin-only closure after rAAA surgical repair results in very low rates of
ACS. On the contrary, a significant minority of patients are discharged with a planned
ventral hernia, which nevertheless, is well tolerated in most cases. Taking everything
into account, the benefits of a routine skin-only closure approach to prevent ACS
development likely outweigh the risks associated with a planned ventral hernia.
