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Comparative outcome of patch angioplasty versus balloon
angioplasty after surgical thrombectomy of thrombosed
arteriovenous hemodialysis graft: 18-month results
Ahmed K. Allam
a
, Atef A.H. Desouki
b
, Abd E. Mohammed
b
a
Vascular Surgery Unit, Department of General
Surgery, Banha University, Banha,
b
Department of Vascular Surgery, Ain Shams
University, Cairo, Egypt
Correspondence to Ahmed K. Allam, MD,
Mohammed Atteiyia Mansour St., Khairy Allam
Building, Benha, 13512, Egypt.
Tel: +20 122 338 3639;
e-mail: ahmed.allam01@fmed.bu.edu.eg
Received: 25 June 2019
Accepted: 20 August 2019
Published: 14 February 2020
The Egyptian Journal of Surgery 2020,
39:60–72
Background
Repeated interventions to keep the well-functioning dialysis vascular access
represent the Achilles heel for hemodialysis patients. Thrombosed permanent
dialysis access, either arteriovenous fistula or arteriovenous graft (AVG)
remains one of the most common and debatable complications regarding
frequency of occurrence and how to manage.
Objective
Our study aims to evaluate mid-term outcomes of surgical thrombectomy of clotted
AVG with adjunctive venous outflow procedures mainly patch angioplasty versus
balloon dilatation to restore their function regarding patency as primary endpoint
and safety as secondary endpoint.
Patients and methods
Between May 2016 and April 2019, 96 of 125 patients with first-time thrombosed
dialysis AVGs were prospectively evaluated after block randomization for surgical
patch angioplasty (group A) versus balloon angioplasty (group B) for venous
anastomotic side after surgical thrombectomy in four tertiary referral hospitals in
Egypt.
Results
Over 18-month follow-up period of our enrolled patients, immediate technical
success was 100% with regaining graft functionality in 100% of 45 patients in
group A patients versus 89.6% (P=0.056) in group B with achieving optimum graft
functionality in 100% of technically successful declotting procedures (43 patients) in
group B. The primary patency at 6, 9, 12 and 18 months in group A was 66, 63.6,
52.3 and 31.8%, respectively, versus 48.8, 48.8, 37.2 and 18.6%, respectively, in
group B. The secondary patency in group A at 6, 9, 12 and 18 months was 86.4,
100, 88.6 and 77.3%, respectively, versus 72.1, 90.7, 79.1 and 69.8%, respectively,
that was not statistically significant except 12-month primary patency (P=0.014).
Conclusion
Our study found no statistically significant difference in 18-month outcomes
between patients treated with surgical thrombectomy with patch angioplasty and
surgical thrombectomy with balloon angioplasty for thrombosed AVGs regarding
regaining functionality and patency, however patients treated with balloon
angioplasty required more additional secondary interventions and most of them
were to manage graft venous anastomotic site restenosis.
Keywords:
angioplasty, arteriovenous graft, thrombectomy thrombosis
Egyptian J Surgery 39:60–72
©2020 The Egyptian Journal of Surgery
1110-1121
Introduction
Polytetrafluoroethylene (PTFE) synthetic grafts are
commonly used as an alternative hemodialysis (HD)
access to native arteriovenous fistula (AVF), it may be
utilized as a secondary option in patients with
exhausted access or as a primary option in patients
with unsuitable native veins, those requiring urgent
dialysis and cannot tolerate waiting for maturation of
native AVF with bridging temporary catheter, elderly
patients with limited life expectancy. One privilege of
synthetic graft over the native fistula is the possibility to
be utilized within 24 h to 15 days of implantation for
dialysis according to its type, this allows patients to
bypass the 45–60-day waiting period for native fistula
to mature [1]. On the other side, lower survival and
higher complication rates are considered the main
drawbacks of this type of dialysis access. Lower
survival rate is mostly due to stenosis and subsequent
thrombosis [2]. Stenosis of synthetic dialysis graft
occurs mostly at venous anastomosis or close to it
due to secondary intimal hyperplasia caused by flow
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60 Original article
©2020 The Egyptian Journal of Surgery | Published by Wolters Kluwer - Medknow DOI: 10.4103/ejs.ejs_126_19
turbulence at the prosthesis-vein interface [3]. Once
graft is thrombosed, access salvage procedure should be
attempted as early as possible according to The
National Kidney Foundation-Kidney Disease
Outcomes Quality Initiative guidelines. It also states
that thrombectomy can be effective after several days
[4]. Owing to the debate concerning how to treat
thrombosed dialysis access and when with the lack
of published evidence, we conducted our study to
evaluate the outcome of surgical thrombectomy with
adjunctive venous anastomosis remodeling either by
patch angioplasty or balloon angioplasty.
Patients and methods
Study design
Our study is a prospective randomized study conducted
between May 2016 to April 2019 at four Tertiary
Referral Hospitals in Egypt (Benha University
Hospital, Ain Shams University Hospital, Nile
Insurance Hospital and Ain Shams Specialized
Hospital). After institutional review committee
approved the study protocol, 96 of 125 patients who
were admitted to vascular surgery department with
first-time thrombosed arteriovenous graft (AVG) of
multiple patterns were randomly divided into two
groups using 1 : 1 block randomization method. All
enrolled patients provided signed informed consent.
Our inclusion criteria were all patients with recently
thrombosed dialysis graft (1–15 days) and AVG
implantation was done by the vascular surgeons of
the registered hospitals. Exclusion criteria were
patients who were operated upon for AVG
implantation outside the registered hospitals,
patients with previous graft interventions either
surgical or endovascular procedure, patients with
evidence of thrombophilia, persistent hypotension
that mandates vasopressor drugs or intravenous fluid
or blood transfusion with dialysis session, patients who
developed heart failure on dialysis, patients with needle
puncture site pseudoaneurysm or infection and lastly
patients with evidence central venous obstruction
diagnosed clinically or documented by computed
tomography venography.
Patient selection
For this analysis we predefined two patient groups:
(1) Group A (n=48) surgical thrombectomy with
adjunctive remodeling of venous anastomotic
side with patch angioplasty.
(2) Group B (n=48) surgical thrombectomy with
adjunctive remodeling of venous anastomotic
side with balloon angioplasty.
All patients referred to vascular surgery departments of
study hospitals due to difficulties during HD or due to
loss of thrill along the AVG. All patients were
investigated by duplex ultrasound. After
confirmation of AVG thrombosis the decision was
surgical declotting of thrombosed grafts with
investigating the venous anastomosis by conventional
venography. All patients underwent graft surgical
thrombectomy using Fogarty catheter.
Methods
All patients were known to have a straight pattern of
brachio-axillary AVG or a loop pattern of arm or chest
wall axillary–axillary 6 mm PTFE AVG with known end
to side reconstruction of venous anastomosis. All
procedures were performed under local anesthesia or
ultrasound guided supraclavicular nerve block in supine
position with patients arm in fully abduction position.
For group A patients, surgical thrombectomy was
performed through longitudinal graftotomy incision
just 2 cm proximal and extended to the hood of
venous anastomosis including at least 2 cm of
apparently healthy distal native vein, we utilized the
same skin incision used to implant the graft. Once
patch angioplasty was decided after on-table
completion venography (Fig. 1a), using Fogarty
thrombectomy catheter 5 and 6 mm (Edwards
Lifesciences LLC, Irvine, California, USA). After
thrombectomy of AVG, regional heparinization
together with diagnostic fistulogram were performed
to evaluate arterial anastomosis and central veins
(axillary vein, subclavian vein and innominate vein) for
any stenosis or segmental occlusion (Fig. 1c).
Remodeling of venous anastomosis and closure of
graftotomy incision using PTFE patch with 5/0 or 6/
0 polypropylenesuture (Fig. 1d). Completion angiogram
was performed through 16 F cannula inserted more
proximally in graft body near arterial anastomotic site.
For group B patients, thrombectomy was performed
through transverse graftotomy incision that located just
3cmdistaltothehoodofarterialanastomosisinstraight
pattern of brachio-axillaryAVG or at the apex of the loop
pattern AVG (Fig. 3a) midway between arterial and
venous anastomosis (Figs 3b and 4a). Following
declotting (Fig. 3b) and regional heparinization of the
thrombosed graft, fistulogramwasaccomplishedthrough
6 or 8 F sheath evaluating both arterial and venous
anastomosis side (Figs 2a and 3d and 4c). Over 0.035
hydrophilic standard terumo wire, balloon dilatation of
venous anastomosis was performed gradually using
Mustang high-pressure balloon (Boston Scientific,
Natick, Massachusetts, USA) and Dorado high-
Patch vs balloon angioplasty after declotting of thrombosed AVG Allam et al. 61
pressure balloon (Bard Peripheral Vascular, Tempe,
Arizona, USA) starting with 8 mm diameter initial
dilatation and finally with 10 mm diameter balloon if
there is residual stenosis (Figs 2b and c and 3e and f and 4d
and e). Completion angiography was done to confirm no
residual stenosis nor rupture of anastomotic suture line
(Figs 2d and 3g and 4f). Closure of graftotomy incision
with interrupted 5/0 or 6/0 polypropylene suture.
Adjunctive graft body and inflow angioplasty was
required some cases of both groups (Fig. 3h and i)
utilizing Mustang 6 mm diameter high-pressure
balloon (Boston Scientific).
Follow-up
All patients were prescribed low molecular weight
heparin in therapeutic renal adjusted dose for 14
days before shifting to oral anticoagulant therapy.
One-day postoperative duplex ultrasound was done
to ensure graft patency before discharge. All patients
were allowed to use recanalized grafts for regular HD as
early as possible to avoid temporary catheter
complications. Follow-up visits were scheduled at 1,
3, 6, 12 and 18-month visit to evaluate graft patency
and dialysis efficacy by palpable thrill and duplex
surveillance, or urgent visits were arranged once graft
functional problem was reported.
Definitions and study outcome measures
The primary endpoints of our study were postprocedural
primary and secondary patency of declotted AVGs after
treatment of venous anastomotic lesion of first-time
thrombosed prosthetic HD grafts. The secondary
endpoints were procedure-related complications and
patient survival within 18 months after
thrombectomy. According to the guideline published
bytheSocietyofInterventionalRadiology[5]we defined
procedural technical success as restoration of flow in the
thrombosed dialysis graft with a palpable thrill along the
course of AVG. Additionally, we included regaining
grafts functionality for both group A and B and less than
Figure 1
(a) Venous anastomosis longitudinal graftotomy. (b) Closure of venous outflow with polytetrafluoroethylene patch after thrombectomy. (c) Dye
injection to confirm central venous system patency (d) patch angioplasty of venous anastomotic side.
62 The Egyptian Journal of Surgery, Vol. 39 No. 1, January-March 2020
a 30% residual diameter stenosis in group B (balloon
angioplasty) as a criterion for technical success. Primary
patency was defined as the time interval after the
procedure until the next access thrombosis or first
subsequent intervention. Postintervention secondary
access patency was defined as the interval following
the index surgical intervention until the access was
surgically declotted, revised or abandoned of the
access circuit. Graft functionality was defined as
ability to deliver a flow rate of at least 350–400 ml/
min without access recirculation to maintain
treatment time of less than 4 h [6]. Major
complications were defined as complications that
required additional treatment or resulted in
permanent sequelae or death. Minor complications
were defined as periprocedural problems requiring no
or nominal therapy with no sequelae [7].
Statistical analysis
We evaluated data for all endpoints in an intention-to-
treat analysis. The initial data entry used Microsoft
Excel (office 365) (2015 Microsoft, Redmond, USA)
for logical proofreading and analysis. We expressed
continuous data as mean±SD and compared
continuous variables using two-sided Student’st-
tests. We estimated primary and secondary patency
Figure 2
(a) Post-thrombectomy stenosis of venous (b) balloon angioplasty with 8 mm high pressure balloon anastomotic site and needle puncture site (c)
balloon angioplasty with 10 mm high pressure balloon (d) completion angiogram with residual stenosis less than 30%.
Patch vs balloon angioplasty after declotting of thrombosed AVG Allam et al. 63
using Kaplan–Meier method. We considered Pvalue
less than 0.05 to be statistically significant. Statistical
analysis was performed by using IBM statistical
package for the social sciences (SPSS) software
(version 22 for Windows program package; SPSS
Inc., Chicago, Illinois, USA).
Results
From 125 patients with first-time thrombosed AVG
presented to the vascular surgery departments
enrolled in our study only 96 patients (59 male
patients 61.5% and 37 females 38.5%) with average
age (49.27±7.67) (Table 1) and with various patterns
of thrombosed AVG (arm straight brachio-axillary
pattern in 70 (73%) patients, chest wall axillo-axillary
loop graft in 13 (13.5%) patients and axillo-axillary
arm loop pattern in 13 (13.5%) patients were eligible
to our inclusion criteria (Table 2). Patients were
randomly divided into two groups using 1 : 1
block randomization method. Group A (n=48)
underwent surgical thrombectomy with adjunctive
Figure 3
(a) Axillo-axillary arm loop arteriovenous graft (AVG) (b) thrombectomy with Fogarty catheter (c) sheath insertion through graftotomy incision (d)
sever stenosis at AVG venous anastomotic (e) marked balloon waisting during angioplasty (f) successful angioplasty site. (g) Completion
venography with no (h) balloon angioplasty of stenotic inflow (i) completion angiography with optimum residual significant stenosis lesion with
axillary artery inflow through AVG.
64 The Egyptian Journal of Surgery, Vol. 39 No. 1, January-March 2020
remodeling of venous anastomotic side with patch
angioplasty and group B (n=48) underwent surgical
thrombectomy with adjunctive remodeling of venous
anastomotic side with balloon angioplasty, patients’
characteristics of both groups are shown in Table 2.
All thrombosed AVG in both groups were found to
have stenosis at venous anastomotic side that was
suggested to be the main etiology of graft failure. The
average number of previously done dialysis access in
group A was three with average years on HD 4.5
versus 4 (P=0.56) and 5.5 (P=0.30), respectively, in
group B (Figs 5 and 6). The mean duration of access
Figure 4
(a) Transverse graftotomy at apex of loop (b) fluoroscopic guided thrombectomy using pattern arteriovenous graft with sheath 8 F through it.
6 mm Fogarty catheter. (c) Residual stenosis at venous anastomosis (d) sever waisting of 8mm high pressure balloon (e) balloon angioplasty
with 10 mm high pressure (f) completion angiogram with optimum outflow balloon.
Patch vs balloon angioplasty after declotting of thrombosed AVG Allam et al. 65
thrombosis in days was 4.5 (2–8) in group A versus 4
(2–6.75) (P=0.55; Fig. 7). Immediate technical
success after surgical declotting was 100% in group
Apatientsversus89.6%ingroupBwithrequired
adjunctive procedure in6.3%ingroupAversus
10.4% in group B (P=0.014). Three (6.3%)
patients of group A required adjunctive central
vein balloon angioplasty due to axillary vein,
subclavian vein and innominate vein significant
stenosis and they were excluded from our study
follow-up protocol. In addition to one (2.1%)
patient whose AVG was ligated postoperatively
due to procedure related infection. In group B, five
(10.4%) patients showed residual outflow significant
stenosis that was not resolved by repeated balloon
angioplasty and required bailout stenting at graft
outflow anastomosis. Those patients were excluded
from our follow-up protocol. Adjunctive inflow
arterial anastomosis angioplasty was done in five
(10.4%) patients in group A versus eight (16.7%)
patients in group B (P=0.35). Intragraft stenosis was
detected in three (6.25%) patients in group B
(P=0.07). Regarding declotted AVG functionality,
all patients of both groups showed successful
postprocedure dialysis session with graft flow rate
more than 400 ml/min proved by duplex. Primary
patency at 6, 9, 12 and 18 months in group A was 66,
63.6, 52.3 and 31.8%, respectively, versus 48.8, 48.8,
37.2 and 18.6%, respectively, in group B with
nonstatistically significant Pvalue except for 12-
month primary patency (P=0.014; Fig. 8)
(Table 3). Secondary patency in group A at 6, 9,
12 and 18 months was 86.4, 100, 88.6 and 77.3%,
respectively, versus 72.1, 90.7, 79.1 and 69.8%,
respectively, in group B with nonstatistically
Table 2 Patients characteristics of the studied groups
Angioplasty Patch (48) [N(%)] Balloon (48) [N(%)] Pvalue
Sex
Male 30 (62.5) 29 (60.4) 0.83
Female 18 (37.5) 19 (39.6)
Age (mean±SD) (years) 49.13±8.85 49.42±6.37 0.85
DM 0 48 (100) <0.001**
HTN 28 (58.3) 24 (50.0) 0.41
IHD 20 (41.7) 21 (43.8) 0.84
Smoking 22 (45.8) 17 (35.4) 0.30
Hemodialysis [median (IQR)] (years) 4.5 (3.25–6) 5.5 (4–6) 0.30
Type of access
Axillo-axillary 11 (22.9) 14 (29.2) 0.49
Brachio-axillary 37 (77.1) 34 (70.8)
Pattern of access
Arm loop 7 (14.6) 6 (12.5) 0.66
Arm straight 36 (75.0) 34 (70.8)
Chest wall loop 5 (10.4) 8 (16.7)
Technical success
Yes 48 (100) 43 (89.6) 0.056
No 0 5 (10.4)
Number of previously done access [median (IQR)] 3 (2–4) 4 (2–5) 0.056
Duration of access/month [median (IQR)] 14.5 (12–17.75) 15.5 (13.25–17) 0.55
Adjunctive procedure
Subclavian vein angioplasty 3 (6.2) 0 0.014*
Stenting 0 5 (10.4)
−45 (93.8) 43 (89.6)
Immediate postprocedure regaining graft functionality 45 (93.8) 43 (89.6) 0.71
Infection
Yes 1 (2.1) 0 0.71
Excluded 3 (6.2) 5 (10.4)
−44 (91.7) 43 (89.6)
Duration of thrombosis [median (IQR)] 4.5 (2–8) 4 (2–6.75) 0.55
Number of add procedure [median (IQR)] 1 (0–1.75) 2 (1–2) 0.007**
*P<0.05 is statistically significant. **P<0.001 is highly significant.
Table 1 Age and sex distribution of the studied group
The studied group (96) [N(%)]
Sex
Male 59 (61.5)
Female 37 (38.5)
Age [mean±SD (range)] (years) 49.27±7.67 (35–69)
66 The Egyptian Journal of Surgery, Vol. 39 No. 1, January-March 2020
significant Pvalue except for 9-month secondary
patency (P=0.04; Fig. 9). Through 18-month
follow-up period six (6.9%) AVGs were ligated;
two in group A and four in group B (Table 3).
Puncture site related infection was the cause of
ligation in four of six (66.7%) AVGs while the
other two grafts were ligated after renal
transplantation. Four (4.6%) patients died during
Table 3 Results of the studied groups
Angioplasty Patch (44) [N(%)] Balloon (43) [N(%)] ZPvalue
Six months follow-up
Primary patency 29 (66.0) 21 (48.8) 1.62 0.11
Secondary patency 38 (86.4) 31 (72.1) 1.65 0.10
Malfunction 2 (4.5) 4 (9.3) 0.88 0.38
Thrombosed 4 (9.1) 8 (18.6) 1.28 0.20
Nine months follow-up
Primary patency 28 (63.6) 21 (48.8) 1.39 1.65
Secondary patency 44 (100) 39 (90.7) 2.07 0.04*
Malfunction 0 3 (7.0) 1.79 0.07
Thrombosed 0 1 (2.3) 1.01 0.31
Twelve months follow-up
Primary patency 23 (63.6) 16 (37.2) 2.46 0.014*
Secondary patency 39 (88.6) 34 (79.1) 1.21 0.23
Malfunction 0 1 (2.3) 1.01 0.31
Thrombosed 2 (4.5) 4 (9.3) 0.88 0.38
Ligated 2 (4.5) 3 (7.0) 0.50 0.62
Died 1 (2.3) 1 (2.3) 0.0 1.0
Eighteen months follow-up
Primary patency 14 (31.8) 8 (18.6) 1.42 0.16
Secondary patency 34 (77.3) 30 (69.8) 0.79 0.43
Thrombosed 5 (11.4) 8 (18.6) 0.94 0.35
Ligated 2 (4.5) 4 (9.3) 0.88 0.38
Died 3 (6.8) 1 (2.3) 1.0 0.32
Mortality
Alive 41 (83.2) 42 (87.7) 0.59 0.56
Died 3 (6.8) 1 (2.3) 1.0 0.32
Ztest of proportion. *Pvalue <0.05 is statistically significant. Pvalue <0.001is highly significant.
Figure 5
Average years of hemodialysis in patients treated with patch angioplasty versus balloon angioplasty.
Patch vs balloon angioplasty after declotting of thrombosed AVG Allam et al. 67
follow-up due to cardiovascular comorbidities and
dialysis related problems; three (6.8%) of which in
group A and one (2.3%) in group B. Totally, 39
additional secondary procedures were performed to
preserve graft patency in group A, central vein
angioplasty was the most secondary procedure
performed (n=21, 53.8%) with median IQR 1.
While in group B, 59 secondary interventions were
performed in form of outflow procedures including
repeated angioplasty, stenting where patch
angioplasty was the most commonly done (n=38,
64.4%) with median IQR 2 (P=0.007; Fig. 10).
Discussion
HD vascular access thrombosis is one of the most
frequent complications encountered by vascular access
surgeons during everyday practice. It represents a
Figure 7
Average thrombosis duration in days in patients treated with patch angioplasty versus balloon angioplasty.
Figure 6
Number of previous dialysis access done in patients treated with patch angioplasty versus balloon angioplasty.
68 The Egyptian Journal of Surgery, Vol. 39 No. 1, January-March 2020
debatable issue for surgeons regarding how to manage
either with surgical declotting or creation of a new
vascular access. As for the patients, it is considered a
major burden to establish a temporary access for dialysis
until construction of a new access, which is difficult in
most of patients especially those with AVG that
indicates exhaustion of most native veins. Therefore,
salvage of thrombosed vascular access is also important
and should be attempted due to the limited native viable
veins and arteries allowing creation of new vascular
access. AVG which is an artificial vascular prosthesis
is used as HD vascular access in the case of failure or
Figure 8
Average thrombosis duration in days in patients treated with patch angioplasty versus balloon angioplasty.
Figure 9
Kaplan–Meire survival curve for primary patency of patch angioplasty versus balloon angioplasty..
Patch vs balloon angioplasty after declotting of thrombosed AVG Allam et al. 69
inability to create native AVF, their crushing
disadvantage is their propensity for venous outflow
stenosis caused by endothelial hyperplasia leading to
thrombosis and graft failure [8]. Neointimal
hyperplasia formation is the main pathogenesis that
results in progressive luminal narrowing causing
thrombosis and graft failure, it mostly occurs at
venous anastomosis (58–90%) [9]. Inflow arterial
anastomotic site and outflow central veins stenosis are
also another anatomical location for this culprit
pathology, unlike the main pathology of outflow and
inflow anastomotic sites, stenosis occurs within the main
graft body remote from anastomotic sites is related to the
development of peri-graft scar and fibroblastic in growth
through needle puncture tracts at the access cannulation
sites [10]. Unlike the USA, in European countries, AVG
is used as the last preference for providing access to HD
before central venous catheter [8]. AVG function is
limited; the primary patency at 6 months is 58% and
at 18 months 33%, secondary patency is 76 and 55%,
respectively [11]. The secondary patency of the AVG is
usually 50% at 3 years and is typically associated with
repeated additional secondary interventions to keep it
patent [12]. Stenoses in venous anastomotic site of graft
(VAG) can be surgically and endovascularly treated.
According to the National Kidney Foundation-
Kidney Disease Outcomes Quality Initiative
guidelines AVG stenoses greater than 50% are
indicated for angioplasty or surgery [13]. Surgical
therapy is open surgical revision-VAG stenosis either
by patch angioplasty to widen the graft outflow or with
jump graft to distal healthy venous segment.
Percutaneous interventions are less invasive than
surgery. The predominant endovascular methods used
are stenosis angioplasty percutaneous transluminal
angioplasty (PTA) [14] and angioplasty with stenting
(PTA+stent) [15]. Surgery should be reserved for
patients in whom balloon angioplasty has failed and
stent implantation is indicated. After three
angioplasties, the patient should be offered surgical
correction as an option [16]. The aim of our study is
to evaluate the outcome of surgically declotted AVG
with remodeling of venous anastomotic site either
surgically with patch angioplasty or balloon
angioplasty, regarding regaining graft functionality
and patency. Regarding clinical characteristics of
patients treated with the surgical and hybrid
procedures including age, sex, risk factors and
duration on HD, no significant differences were
found between the two groups, except for diabetes
mellitus, hypertension was the dominant risk factor in
52 (54.1%) patients of both groups. flow arteries were
mostly brachial artery in 71 (74%) patients and the
outflow veins were axillary vein in all patients (100%).
Regarding the index procedure characteristics including
type, pattern of dialysis access and functionality of index
procedure were comparable between both groups of our
study. Ko et al. [17] compared outcomes of hybrid and
Figure 10
Kaplan–Meire survival curve for secondary patency of patch angioplasty versus balloon angioplasty.
70 The Egyptian Journal of Surgery, Vol. 39 No. 1, January-March 2020
surgical correction for de novo AVG occlusion their
patients and procedure characteristics are comparable
except for age, hypertension was the dominant risk factor
in overall 49 (83.1%) patients. The outflow vein was the
basilic vein in their study. Kao et al. [18] study reported
that the two groups (balloon angioplasty group and
surgical revision group) were similar in age, sex
distribution, and medical comorbidity, hypertension
was the dominant risk factor in both groups 155
(53.1%) patients. The pattern of declotted AVG in
our study 13 (13.5%) arm loop, 70 (73%) arm straight
and 13 (13.5%) chest wall. In Ko et al. [17] study forearm
loop graft was the dominant pattern 54 (91.5%) and
upper arm straight graft five (8.5%). Our study technical
success and regaining graft functionality were
comparable in both groups with nonstatistically
significant difference in both primary and secondary
patency except for 12-month primary patency and 9-
month secondary patency. The Kaplan–Meier estimates
of 12-month primary patency rates were 63.6% in the
patch angioplasty group and 37.2% in the hybrid group.
Ko et al. [17] 12-month primary patency were
comparable to our results, their 12-month primary
patency rates were 47 and 30% but were not different
between the hybrid and surgery groups (P=0.73). This
may be explained by their small number of the studied
patients (59 patients). Ko [16] compared the outcome of
four adjunctive treatment modalities after surgical
declotting of thrombosed AVG. Compared to our
study and according to Kaplan–Meier analysis, the
survival curve for primary patency in the group treated
with thrombectomy and intraoperative angioplasty,
group treated with thrombectomy and sequential
angioplasty and group treated with thrombectomy and
patch angioplasty did not statistically differ in graft
patency. Kao et al. [18] compared balloon angioplasty
versus surgical revision for thrombosed dialysis graft
outlet stenosis after thrombectomy in 289 thrombosed
graft and their findings regarding primary patency
showed no difference between both groups. Dapunt
et al. [19] reported 1 week, 1 month, 1 year and 15
months. patencyrates of 95, 72, 31 and 27%, respectively,
for 22 PTA patients and 78, 64, 19 and 19%, respectively,
for 22 surgical patients with no significant difference
betweenbothgroups. Theoverallinfection ratewasthree
of 44 (6.8%) patients in group A versus two of 43 (4.6%)
patients. The cause of infection was mainly puncture site
infection except one patient in group A was infected
immediately postoperative. Our study showed that
surgical revision allows direct evaluation of the lesion
and precise anatomic correction of the outlet stricture,
but balloon angioplasty can offer more therapeutic
options. According to our findings and the
comparative results of this study, the surgical revision
group apparently exhibited a higher graft survival,
although the difference was not statistically
significant. Intraoperative adjuvant angioplasty for
thrombosed grafts in a single procedure is simpler and
faster but associated with a highly statistically significant
number of additional secondary interventions mainly on
graft outlet due to restenosis. It has been recently shown
that utilization of stent grafts to treat VAG of HD access
appears to provide longer patency when compared with
PTA alone [15]. The stent is coated with ePTFE inside
and this material is identical to material from which
AVGs are manufactured. This endovascular approach
converts the initial surgical end-to-side venous
anastomosis into an end-to-end anastomosis
providing more laminar in line flow [20]. Graft outlet
stenosis was found in all studied patients of both groups
in association with other different locations like central
venous outflow, puncture site and graft inflow, these
finding may necessitate using intraoperative fistulogram
to identify possible graft stenotic sites and may indicate
that surgical thrombectomy alone does not ensure the
optimum outcome in dialysis graft thrombosis.
Conclusion
Our study found no statistically significant difference
in mid-term outcomes between patients treated with
surgical thrombectomy with patch angioplasty and
surgical thrombectomy with balloon angioplasty for
thrombosed AVGs regarding regaining functionality
and patency, however patients treated with balloon
angioplasty required more additional secondary
interventions and most of them were to manage
graft venous anastomotic site restenosis. This may
encourage future utilization of stent graft to decrease
restenosis rate but also will be associated with increase
procedure expenses.
Financial support and sponsorship
Nil.
Conflicts of interest
There are no conflicts of interest.
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