Keywords descending aorta - aortobronchial fistula - aortoesophageal fistula - endovascular
repair
Introduction
Aortobronchial fistula (ABF) and aortoesophageal fistula (AEF) are rare but potentially
life-threatening complications of both treated and untreated aortic disease due to
exsanguinating hemorrhage. By classification, primary fistulas occur as communications
between the untreated aorta and the bronchial tree/esophagus due to aneurysm rupture,
penetrating aortic ulcer, advanced esophageal or lung cancer, or ingestion of foreign
body. Secondary fistulas originate from reconstructed aorta (prosthetic graft) or
develop secondary to complications of a visceral surgical procedure (anastomotic insufficiency).[1 ]
Compared with results of open surgery for thoracic aortic aneurysm (TAA) with a mortality
of 14%,[2 ] open aortic surgery in ABF and AEF is endowed with a significantly increased mortality
of 24[3 ] and 50%,[4 ] respectively, clearly reflecting the complexity of those lesions. Therefore, less
invasive concepts to reduce perioperative mortality have been evaluated with special
attention on thoracic endovascular aortic repair (TEVAR). Since the first report of
TEVAR in TAA (13 patients) in 1994,[5 ] the technique has rapidly evolved and currently is the primary recommendation for
treatment of aneurysms of the thoracic aorta.[6 ] Although until today, no randomized trials of open versus endovascular TEVAR have
been performed. Evidence has accumulated that there are advantages of TEVAR over open
repair in terms of survival in the short term.[2 ]
Therefore, the objective of this study was to analyze our results of TEVAR in the
treatment of ABF and AEF.
Patients and Methods
Between September 1995 and March 2012, nine patients (three women, six men) with a
mean age of 65 ± 12 years (range, 48–80 years) were treated by endovascular stent
graft placement in the thoracic aorta (TEVAR) for ABF or AEF. For the subsequent report,
patients are divided into an ABF group[1 ]
[2 ]
[3 ]
[4 ]
[5 ] and an AEF group[6 ]
[7 ]
[8 ]
[9 ] ([Table 1 ]). Preoperative imaging protocol consisted of high-resolution spiral computed tomography
(CT) scan and additional magnetic resonance image in selected cases. Preprocedural
planning was based on 3D reconstructions obtained with the Aquarius workstation (TeraRecon,
Frankfurt, Germany). For postprocedural imaging analysis (2D maximum intensity projection
and 3D volume rendering), the OSIRIX software (Pixmeo SARL, Geneva, Switzerland) was
used. At our institution, endovascular treatment is performed by an interdisciplinary
approach of vascular surgeons and interventional radiologists. Informed consent was
obtained either by the patients themselves or by the relatives for the remaining cases.
The implantation procedures were performed according to standard protocol in a hybrid
operating room equipped with a ceiling-mounted digital subtraction angiography (Siemens
Artis Zee, Erlangen, Germany). All cases were operated with standby for cardiopulmonary
bypass available, in case a conversion to open procedure would be necessary. The operations
were in most cases performed under general anesthesia and ABF patients were intubated
with a double lumen tube to allow for selective ventilation of the nondiseased lung.
In selected cases, cardiac overpacing (180 bpm) was used to reduce blood flow during
deployment of the graft.
Table 1
Perioperative patient data
Pat.
Gender
Age
Diagnosis
History
Location of fistula
Follow-up
1
Male
48
ABF, II
Anastomotic pseudoaneurysm after repair of aortic coarctation (patch 1967, tube-graft
1968)
Left upper segment bronchus
Alive at 188 months, Re-TEVAR in 2004
2
Male
77
ABF, I
TAA (5 cm)
Left lower segment bronchus
Nonrelated death (age 82) at 61 months
3
Female
61
ABF, I
PAU
Left bronchial mainstem
Alive at 151 months
4
Male
74
ABF, I
PAU
Left lower segment bronchus
Nonrelated death (colon cancer) at 10 months
5
Male
80
ABF, I
Postdissection TAA (6.5 cm)
Left lower segment bronchus
Alive at 3 months
6
Female
60
AEF, I
Malignant fistula of metastasized esophageal cancer, palliative treatment
Died after 7 months (tumor cachexia)
7
Male
71
AEF, II
Anastomotic insufficiency with aortic erosion after esophageal resection for esophageal
cancer (pT2B pN1 M0)
Died on day of TEVAR (sepsis/multiorgan failure)
8
Male
68
AEF, II
Anastomotic insufficiency with aortic erosion after esophageal resection for esophageal
cancer (pT1B pN0 M0)
Died after 3 months (in hospital) due to recurrent sepsis/pneumonia
9
Female
48
AEF, I
Ruptured mycotic aneurysm of distal thoracic aorta due to Boerhaave Syndrome with
esophageal perforation
Alive at 22 months, Re-TEVAR (prox. extension) at 3 months
Abbreviations: ABF, aortobronchial fistula; AEF, aortoesophageal fistula; I, primary
fistula; II, secondary fistula; Pat., patient; PAU, penetrating aortic ulcer; prox.,
proximal; Re-TEVAR, redo-thoracic endovascular aortic repair; TAA, thoracic aortic
aneurysm.
The follow-up protocol encompassed clinical visit with repetitive high-resolution
contrast-enhanced spiral CT scans with early and late phase series and a chest X-ray
after 1, 3, 6, and 12 months with annual repetitions thereafter.
Results
According to the above-described method, we have implanted 14 stent grafts in the
descending aorta in a series of nine patients ([Tables 1 ] and [2 ]). The mean operative time for the TEVAR procedure including surgical arterial access
and arterial closure was 124 ± 54 minutes (range, 65–200 min). For Patient 3, operative
time was prolonged to 315 minutes because of difficult access and aortofemoral reconstruction,
in patient 9, visceral debranching was performed immediately after TEVAR (245 minutes).
All patients survived the operative procedure and sealing of the aortic lesion could
be achieved in all cases resulting in a technical success rate of the implantation
procedure of 100%. Proximal landing zone was located in zone 3 in the majority of
cases ([Table 2 ]), overstenting of the left subclavian artery has not been performed in this series.
Table 2
Stent graft details
Graft
Pat.
Device
Size (mm)
Arterial access
Landing zone (0–4)
Anesthesia
Comments
1
1
Stentor
26 × 50
External iliac
4
General
Iliac access due to shortness of introducer sheath
2
Talent
30 × 100
Common femoral
3
Local
Proximal and distal extension for recurrent ABF at 96 months
3
2
Talent
36 × 130
Aortofemoral graft (PTFE 10 mm)
3
General
4
Talent
36 × 110
Femoral (PTFE graft)
3
General
Distal extension for recurrent ABF at 5 months
5
3
Vanguard
24 × 50
Common femoral
3
General
6
4
Talent
30 × 110
Common femoral
4
General
7
5
Relay NBS plus
34 × 154
Common femoral
3
Local
8
6
Valiant
28 × 150
External iliac
3
General
9
7
Valiant
38 × 160
Common femoral
3
General
Bail-out procedure in general surgery OR using plain fluoroscopy (C-arm)
10
Valiant
42 × 150
11
Valiant
42 × 150
12
8
Valiant
32 × 150
Common femoral
3
General
13
9
Valiant
32 × 130
Common femoral
4
General
Simultaneous visceral debranching
14
Relay plus
28 × 215 × 20
Common femoral
3
General
Tapered graft for proximal extension at 3 months
Abbreviations: NBS, nonbare stent; Pat., patient; PTFE, polytetrafluoroethylene.
For the ABF group, all five patients recovered and were discharged home from the hospital,
resulting in a perioperative mortality of 0%. In the long-term follow-up, two patients
are alive and well after 188 and 151 months, respectively. Two patients died after
61 and 10 months, respectively, because of nonrelated causes. In two cases,[1 ]
[2 ] redo TEVAR had to be performed for recurrent hemoptysis at 5 and 96 months ([Fig. 1 ]). Interestingly, both patients continued to expectorate bits of hematoma for 2 weeks,
after which no further episodes of expectoration were noted. The procedure-related
morbidity was found to be one of the five patients: in Patient 2, conversion from
femoral to iliac and finally to aortic access had to be performed because of extensive
iliac occlusive disease. For introduction of the stent device, a 10-mm polytetrafluoroethylene
conduit was used and completed to an aortofemoral bypass at the end of the procedure.
Thrombosis, embolization, or clinical manifestations of impeded blood flow as well
as postoperative stroke or paraplegia could not be detected. Completion angiograms
and postoperative CT scan confirmed satisfactory position of the implanted stent graft
in each case and showed no sign of endoleak or dislocation. All patients were transferred
to the intensive care unit for postoperative monitoring, and prolonged duration of
mechanical ventilation (9 days) was only necessary for Patient 3 because of cardiopulmonary
arrest and underlying chronic obstructive pulmonary disease. Patients were either
discharged home,[2 ] retransferred to the referring hospital,[1 ] or discharged into rehabilitation.[2 ] All patients with ABF received long-term oral antibiotic treatment (broad-spectrum
gyrase inhibitor) for 6 weeks postoperatively. Complete resolution of the extensive
periaortic hematoma was noted in Patient 3.[7 ]
Fig. 1 Male patient aged 48-year-old presenting with hemoptysis and history of 2x aortic
surgery (patch/tube graft) for coarctation during childhood. Computed tomography (CT)
and digital subtraction angiography detect small pseudoaneurysm at the site of previous
aortic surgery (A, B). TEVAR using first generation implant (Stentor, MinTec, Freeport,
Bahamas) successfully sealed the lesion (C, D). At 96 months, patient presented with
recurrent hemoptysis and material fatigue was evident in CT (E, F). Aortic relining
was performed (Talent, Medtronic, Minneapolis, Minnesota, United States) and at 188
months, Stentor and Talent grafts are in situ without signs of dislocation or recurrent
hemoptysis (G, H).
For the AEF group, only one patient[9 ] is alive after 22 months ([Fig. 2 ]). This patient presented with a ruptured aortic aneurysm at the thoracoabdominal
level that in retrospection was attributed to an esophageal perforation (Boerhaave
Syndrome). Following emergency TEVAR and visceral debranching (superior mesenteric
and splenic artery with vein graft), the esophageal lesion was sealed with a stent
as bridging procedure and the mediastinal abscess was drained. After 3 months, removal
of the stent and esophageal resection was performed. The patient recovered from the
procedure and could be discharged home but had to be readmitted for dilatation of
a stenosis of the esophagogastric anastomosis repeatedly. However, no recurrent hematemesis
or aortic endoleak could be detected at 22 months after the initial TEVAR. Two patients
with secondary fistula (aortic erosion because of anastomotic insufficiency and mediastinitis
following esophageal resection for esophageal cancer, Patients 7 and 8) died in hospital.
One shortly after TEVAR (day 1), the other after recurrent episodes of sepsis/pneumonia
due to persisting esophagobronchial fistula despite combined esophageal and bronchial
stent placement in multiorgan failure 3 months after TEVAR. In Patients 7 to 9, bronchial
lavages/drainage specimen revealed multiple gram-positive bacteria and candida species.
Therefore, all patients received calculated broad-spectrum antibiotics (third generation
cephalosporin + gyrase inhibitor) in hospital. Patient 9 was discharged with a gyrase
inhibitor until readmission for esophageal resection. The fourth patient with AEF[6 ] was treated in a palliative situation of metastasized esophageal cancer (25 cm from
the mouth/teeth) and died 7 months postoperatively in a nursing home because of tumor
cachexia.
Fig. 2 Female patient aged 48-year-old presenting with hematemesis and epigastric/chest
pain. Computed tomography (CT) shows ruptured aneurysm of distal thoracic aorta due
to Boerhaave symdrome (A). Emergency TEVAR (Medtronic Valiant 32 × 130 mm) (B) and
subsequent visceral revascularization with aortosplenic (upper arrow) and aortomesenteric
(lower arrow) bypasses (greater saphenous vein, C) was performed. Follow-up CT at
22 months shows stent graft in place (after proximal extension with Bolton Relay BS
28 × 215 × 20 mm after 3 mo) and patent visceral bypass grafts (D).
Discussion
Treatment of ABF and AEF aims at two major goals: immediate control of aortic bleeding
and closure of the fistula. The first, however, puts high requirements on logistics
for an open operation that are often not easily met.[8 ] Consequently, as TEVAR has the advantage of rapid aortic sealing at low invasiveness,
attempts were undertaken to adopt TEVAR in the treatment of ABF. In 1996, the first
two successful cases of TEVAR in ABF were reported by Campagna et al and Chuter et
al.[9 ]
[10 ] Since then, the technique has been used more widely, however, single center series
are very limited because of the low incidence of ABF and AEF. Currently, there are
two articles that focus on the outcomes of TEVAR in ABF and AEF: Jonker et al conducted
a literature survey and identified 71 cases of ABF and 43 cases of AEF with an in-hospital
mortality of 3% and 19%, respectively, and a mean follow-up of 10 months.[11 ] Chiesa et al published a multicenter study where 25 cases of ABF,[13 ] AEF,[11 ] and both ABF/AEF[1 ] were pooled from 17 centers. Here, 30-day overall mortality was high (56%) and not
different between ABF and AEF and follow-up was 22.6 months.[12 ] From both series, it clearly emerges that ABF and AEF are distinct entities, which
require different treatment modalities.
With respect to ABF, additional evidence has been accumulated, which corroborates
safety and also long-term efficacy of TEVAR: Riesenman et al published their institutional
series of 5 cases and added a literature survey yielding a total of 67 cases (4 reports
with n ≥5) with an overall 30-day mortality of 1.5% and mean follow-up of 21.5 months.[13 ] De Rango et al compiled a total number of 87 cases (3 reports with n ≥ 5), however, no overall analysis of mortality and follow-up was performed.[14 ] Throughout the cited publications, mean/median follow-up did not exceed 42.6 months.
The largest single-center series (n = 11) of TEVAR in ABF also stated beneficial results with safe and effective management
(0% mortality), however, follow-up was limited to 8.8 months.[15 ] Our previously published results of patients treated by TEVAR for ABF[7 ]
[16 ]
[17 ] were in line with those data and we have now expanded our series to five patients
with a mean follow-up of 82.6 months, which represents the longest currently available
single-center follow-up for this patient entity. All of the patients survived, and
there was only minor procedure-related morbidity (aortofemoral bypass for access in
severe iliac occlusive disease).
Since the first report of TEVAR in a patient with AEF by Oliva,[18 ] the current series in the literature, as reviewed by Jonker et al, consists of 43
cases in total.[11 ] However, institutional series is limited to a few cases, with the report by Topel
et al probably being the most extensive (n = 5).[1 ] In addition, multicenter studies from European centers are available that report
series of 11 patients with TEVAR in AEF.[12 ] As mentioned above, prognosis of AEF differs largely from that of ABF. In-hospital
mortality of TEVAR in AEF patients ranges from 19% in the meta-analysis[11 ] to 31%.[12 ] However, reports of open surgery in AEF are even more sparse and in one of the larger
series, published by Kieffer in 2003, perioperative mortality is 50%.[4 ] Therefore, TEVAR in that setting has been added to the armamentarium of vascular
surgeons to serve as a “bridge” to open surgical repair[19 ] and should be regarded as a first choice lifesaving procedure as it is able to control
the life-threatening bleeding.[8 ] Of the four AEF cases presented in the series, one is caused by an infiltration
of the metastasized esophageal carcinoma into the descending aorta (malignant fistula).
In that case, patient's comorbidity was prohibitive of primary open surgical repair
as well as secondary esophageal resection. TEVAR in case of primary malignancy–induced
AEF has also been described before,[20 ] although survival was limited to 3 months due to recurrent bleeding complication.
In our case, patient was able to be discharged to nursing home and suffered death
from tumor-induced cachexia after 7 months, however, without recurrent episodes of
bleeding.
It has been highlighted, that key element of treatment in AEF patients is correction
of esophageal lesion[8 ]
[19 ] as survival of AEF patients without esophageal surgery is significantly limited.[1 ]
[11 ] Placement of esophageal stents has emerged as a valuable tool, however, unlike aortic
stent grafts, in our patients they were not able to seal the lesion completely and
therefore cannot exclude risk of mediastinitis. Based on our results, definitive surgical
correction seems vital to obtain a reasonable long-term perspective and possible techniques
include esophageal resection with gastric pull-up, esophagoplasty, or the “Thal” fundoplication.
In summary, we were able to successfully control acute bleeding from the descending
thoracic aorta due to ABF and AEF in a series of nine patients applying endovascular
treatment techniques (TEVAR). Our results with 0% perioperative mortality for the
ABF-group compare well the literature and our follow-up of 82.6 months is the longest
published so far. Consequently, TEVAR can be seen as safe, reliable, and durable treatment
of ABF without the actual need for secondary conversion (removal of stent graft).[21 ] In our experience, even for recurrent hemoptysis (because of material fatigue),
redo TEVAR seems justified. For AEF, TEVAR also provides a straightforward method
to achieve bleeding control by aortic sealing. However, the accompanying esophageal
lesion is limiting the long-term prognosis by recurrent sepsis and therefore, TEVAR
and esophageal stenting should be considered a bridging procedure to open surgery
in those patients. However, it must be subjected to further evaluation, if an aortic
conversion operation (e.g., endograft replacement by homograft,[1 ] or pericardium[22 ]) indeed is necessary, or if the endograft can remain in situ and only the esophageal
lesion is targeted.
