ABSTRACT
Objective: To
report our experience with supra-genicular femoropopliteal bypass performed for
critical limb ischemia.
Methods: This is a retrospective review
of supra-genicular femoropopliteal bypass were performed at our vascular
surgery unit in King Hussein Medical
Center, Amman, Jordan,
between March 2008 and March 2010. Sixty three patients (49 male, 14 female)
had 67 procedures (bilateral in 4 patients). Fifty seven procedures done in 53
patients for critical limb ischemia were followed up for twelve months. During
this period eight patients were lost to follow-up and were also excluded from
the analysis. Records of the remaining 45 patients (35 male, 10 female) with 49
procedures were analyzed for operative details, patient risk factors, primary
patency rates, complications, limb salvage rates. The surgical technique was
uniform. Follow-up was clinical and by duplex scanning at six weeks, three and
six months, and one year. Graft patency was considered terminated if the
patient had an occluded graft or needed further procedures to keep the graft
patent.
Results:
In 31 (63.3%) limbs the indication for the procedure was tissue loss,
while in 18 (36.7%) it was rest pain. The primary end point was primary graft
patency calculated as 69.4% (reversed long saphenous vein 83.3%, prosthetic
61.3%). The limb salvage rate was 83.7% (reversed long saphenous vein 88.9%,
prosthetic 80.6%). Five major limb amputations were done for non-healing wounds
and three for prosthetic graft infections. Procedure related complications
included surgical wound problems,(5) and nerve injuries.(4) The most ominous complication was prosthetic graft infection as three out
of four resulted in graft occlusion and removal and eventual limb loss while
one was replaced by saphenous vein. Perioperative 30 day mortality was two
(3.8%) patients while another six (11.3%) died during the one year follow up
period.
Conclusion: Supra-genicular
femoropopliteal bypass performed for critical ischemia has an acceptable
patency rate at one year and is an effective mean of limb salvage. Prosthetic
graft infections are a main cause of limb loss. The use of vein conduits should
be aggressively pursued.
Key words: Bypass, Critical, Femoropopliteal, Ischemia, Supra-Genicular
JRMS
June 2012; 19(2): 25-29
We report our experience in the specific subset of patients
who had supra-genicular femoropopliteal bypass for critical ischemia. We aim to
show the short term results that impacted our practice as to the use of the
procedure and best conduit.
Methods
Sixty-three patients (49 males, 14 females) with a
median age 61 (41-83) underwent 67 supra-genicular femoropopliteal bypass operations
at the vascular surgery unit in King Hussein Medical
Center, Amman, Jordan
between March 2008 and March 2010. In 53 patients, with 57 procedures, the
indication was critical leg ischemia defined as rest pain or tissue loss. A
further eight patients were excluded from our analysis due to loss to follow up
during the study period. Data relating
to 45 patients (35 males, 10 females) who underwent 49 procedures (bilateral in
4 patients) was analyzed for outcome and complications.
Data
was collected retrospectively from patient charts, operative records and duplex
surveillance records in our vascular laboratory. Patient characteristics and
anatomical risk factors including degree of ischemia and vessel run-off status
were collected. Procedure related data
including type of conduit, occlusion rates, primary patency rates, and
complications were also collected. A diagrammatic presentation of the procedure
is shown in Fig. 1. The surgical technique followed is classically described in
the literature. The types of bypass grafts placed were reversed long saphenous
vein (RLSV; n=18) and expanded polytetrafluoroethylene (ePTFE) grafts of 6–8-mm
diameter with external support (n =31).
Intravenous
second generation cephalosporin and the appropriate dose of unfractionated
heparin were given perioperatively. All patients had regular follow-up which was
started pre-discharge with ankle brachial index measurement supplemented by duplex
scan for those with no
improvement in ABPI. Further follow-up was according
to our surveillance program which includes
duplex scans at 6 weeks, 3 months, 6 months, then annually post operatively.
The frequencies
of clinic visits for wound healing and symptomatic improvement were tailored to
each individual case. The primary end points were primary graft patency rates,
while the secondary end points were limb salvage and graft infection rates. Graft
failure was determined by clinical examination and confirmed by duplex scan. Graft
patency was considered terminated when thrombosis occurred or when revision surgery
was performed for failing graft. Patients who died before discharge or those
with inadequate records were excluded from the analysis of graft patency and long-term
outcomes because of absence of follow-up data. The perioperative factors
studied included gender, diabetes mellitus, hypertension, smoking, hyperlipidemia,
ischemic heart disease, status of distal run-off, preoperative ankle–brachial
index, and the type of graft material used.
Results are summarized as means and range for
continuous variables while categorical data are summarized as counts or
percentages.
Results
Patient demographics are presented in Table I. The indication for surgery was rest pain in
18 (36.7%) procedures and tissue loss in 31 (63.3%). The mean ABPI was 0.3 (0.1-0.6)
pre-operatively and 0.5 (0.4-1.0) post-operatively.
All patients were followed up for a minimum of 12
months. The overall primary graft patency rate at one year was (69.4%) where 15
grafts (3 RLSV, 12 prosthetic) occluded during the study period.
RLSV grafts had better primary patency at 83.3%
compared to 61.3% for prosthetic grafts. The cumulative limb salvage rate was 83.7%
at one year. RLSV grafts also had better limb salvage rate at 88.9% compared to
80.6%. Eight major limb amputations were done: five for non- healing wounds and
three for prosthetic graft infection. Inflow source was 45 native common
femoral artery, two aortofemoral bypasses, one axillofemoral bypass, and one
femorofemoral bypass. The run off was a patent popliteal in 48 procedures, a
blind popliteal segment in one procedure, one tibial vessel in 21 and two
tibial vessels in 28 procedures. Procedure related complications are detailed in
Table II.
Adjuncts measures used to aid healing included surgical
wound care, applications of vacuum assisted dressings and
skin grafts.
Perioperative
30 day mortality was two (3.8%) patients (both due to cardiac ischemic events)
while another six (11.3%) died during the follow-up period.
Discussion
Since Kunlin performed the first bypass with an
autologous saphenous vein in 1949, bypass grafting has proved to be an
effective form of treatment for peripheral arterial occlusive disease and
became one of the commonest vascular procedures performed.(3,4) In the current era of interventional non-surgical options first, the
indication for the procedure is being constantly updated. As a matter of policy
we treat the majority of our claudicant population conservatively as we ascribe
to the point of view that intermittent claudication is a life style disease
rather than limb threatening condition.
In addition, limb loss following revascularization is a concern in
patients presenting with intermittent claudication which makes infrequently
justified procedure.(1,4)
The above policy in our unit meant that the vast
majority of our supra-genicular femoro-popliteal procedures are done for
critical leg ischemia. This is defined according to Fontaine classification of
leg ischemia (stage 1:
asymptomatic, stage 2: claudication, stage 3: rest pain, stage 4:
ulceration or gangrene) as Fontaine stages three and four.(5) Toe pressure measurements are unfortunately not available in our unit and
such are not used in the definition. Adequate and immediate revascularisation
in critical ischemia is a great advantage of the procedure in terms of limb
salvage. It is our view that critical leg ischemia is a more justifiable
indication for the procedure. Another good reasoning for performing the
procedure in patients with critical ischemia is the great difference it makes
in terms of life quality for the rest of those patients anticipated limited
survival. Interventional therapies with balloon
angioplasty and stenting are always used first line in our unit. This is especially
true when vein conduits are not available. The non feasibility or failure of
interventional therapy warrants surgical intervention. The mean survival of
patients who undergo femoropopliteal bypass for limb salvage is significantly
shorter than those for claudication (57% versus 82% five-year survival rate) as
limb-threatening ischemia is a manifestation of advanced generalized
atherosclerosis.(1,6,7)
Aggressive management of these patients’ risk
factors is warranted. The small sample size in our study makes it difficult to
draw any conclusions regarding these risk factors, however the multitude of
these factors especially coronary artery disease and tobacco use is noticeable.
The one year graft patency and limb salvage rates at
69.4% and 83.7% in our series is comparable to those in the published
literature. The difference between graft patency and limb salvage rates is
explained by the fact that once the ulcer or ischemic injury has healed, the
limb-threatening condition might not recur on graft blockage.(1,5,7,8) There has been a lot of debate in the
medical literature regarding the best type of conduit for primary use in these
patients. None of the studies showed PTFE to be superior or even equivalent to
saphenous vein as graft material for above-knee femoropopliteal bypasses. The
mean difference in 5-year patency was 20%, which is clinically relevant. Indeed, a significant
difference in patency is already observed at one year.(3)
The above mentioned studies however do not on the
whole differentiate between critical limb ischaemia and claudication as an
indication. This is the main theme discussed in our paper. In a recent meta-analysis,
which dealt with critical ischemia, the difference between the vein graft
series and the prosthetic graft series was readily apparent and significant at
most yearly intervals. The paucity of above knee vein graft series was evident
and possibly reflected a more extensive popliteal involvement above the knee than
below it, a better opportunity for using below knee vein grafts in situ, or
both. The validity of the vein-sparing approach in terms of graft patency was
denied even more emphatically than for claudicant patients. Because patients
with critical ischemia deserve the best operation on the first occasion, an
above knee prosthetic bypass should not be recommended in the presence of a
usable saphenous vein.(9,10) When the operative indication is chronic
critical ischemia, data strongly support the preferential use of vein over
prosthetic conduits for femoropopliteal bypass grafting.(11,12)
The noticeable high rate of prosthetic use in our
series is multifactorial. Some of the reasons are: non-availability of vein
grafts, anticipated short life expectancy, and compromised patient condition.
However, some are done for lack of staff and theatre time availability or as an
emergency procedure in a poorly patient. We do realize the weakness of this
justification and have recently, following the analysis of our results, moved
to a vein only policy when possible. The mechanisms of graft failure between
prosthetic and vein grafts differ. There is more sudden thrombosis in
prosthetic grafts and greater myointimal hyperplasia in vein grafts — this is
better identified by using a postoperative duplex surveillance program—as well
as a greater need for urgent reoperation or a repeat bypass after prosthetic
bypass which on the whole less successful.(12,13,14) Sparing a saphenous vein is also unreasonable because the rate of use of
a saved vein in a late bypass has been consistently low, alternative autologous
veins are often available for secondary bypass, and a failing vein graft can be
treated with no further bypass. Hence, a smaller number of graft failures,
together with less severe consequences of failed or complicated grafts,
strengthen the argument for the use of a saphenous vein in primary
femoropopliteal bypass.(9,10,15)
Prosthetic graft infection is one of the main
reasons for limb loss in our series and adds to the argument for primary use of
vein grafts when available. We have moved recently to a vein first policy for
all our bypasses and hope this will be reflected in a better outcome in the
future. Infection of prosthetic grafts may not be as rare as the frequency of
1-2 % suggested in some studies. Indeed, Pedersen et al. reported a
graft infection rate of 12% in 141 supra-genicular prosthetic grafts for
claudication.(10,15,16)
Complications
of the procedure add to its morbidity in terms of nerve injuries and wound
problems but are offset by the benefit of limb salvage.
Conclusion
Supra-genicular femoropopliteal bypass performed for
critical ischemia has an acceptable patency rate at one year and is an effective
mean of limb salvage. Prosthetic graft infections are a main cause of limb
loss. The use of vein conduits should be aggressively pursued.
References
1.Lau H, Cheng SW. Long-term prognosis of femoropopliteal bypass: an analysis of 349
consecutive revascularizations. ANZ J Surg. 2001 Jun; 71(6):335-40.
2.Koscielny A, Pütz U, Willinek W, et
al. Case-control comparison of profundaplasty and
femoropopliteal supragenicular bypass for peripheral arterial disease. Br J
Surg. 2010 Mar; 97(3):344-348.
3.Klinkert P, Post PN, Breslau PJ, et
al. Saphenous vein versus PTFE for above-knee
femoropopliteal bypass. A review of the literature. Eur J Vasc Endovasc
Surg. 2004 Apr; 27(4):357-362. Review.
4.Pullatt R, Brothers TE, Robison
JG, et al. Compromised bypass graft outcomes after
minimal-incision vein harvest. J Vasc Surg. 2006 Aug; 44(2):289-294.
5.Dieter RS, Chu
WW, Pacanowski JP Jr, et al.
The significance of lower extremity peripheral arterial disease. Clin
Cardiol. 2002 Jan; 25(1):3-10. Review.
6.Dawson I, van Bockel JH, Brand R. Late nonfatal and fatal cardiac events after infrainguinal bypass for
femoropopliteal occlusive disease during a thirty-one-year period. J. Vasc.
Surg. 1993; 18: 249–260.
7.Nicoloff AD, Taylor LM Jr, McLafferty RB, et al. Patient recovery after infrainguinal bypass grafting for limb salvage. J.
Vasc. Surg. 1998; 27: 256–263.
8. Abou-Zamzam AM Jr, Lee RW, Moneta
GL et al. Functional outcome after infrainguinal bypass for
limb salvage. J. Vasc. Surg. 1997; 25: 287–297.
9.Archie JP Jr. Femoropopliteal bypass with either adequate ipsilateral reversed saphenous
vein or obligatory polytetrafluoroethylene.
Ann Vasc Surg
1994; 8:475-484.
10.Pereira CE, Albers M, Romiti M, et
al. Meta-analysis
of femoropopliteal bypass grafts for lower extremity arterial insufficiency. J
Vasc Surg 2006 Sep;44(3):510-517.
11.Jackson MR, Belott TP, Dickason
T, et al.
The consequences of a failed femoropopliteal bypass grafting: comparison
of saphenous vein and PTFE grafts. J Vasc Surg. 2000 Sep; 32(3):498-504;
504-5.
12.Klinkert P, Schepers A, Burger
DH, et al.
Vein versus polytetrafluoroethylene
in above-knee femoropopliteal bypass grafting: five-year results of a
randomized controlled trial. J
Vasc Surg 2003;37(1):149-55.
13. John TG, Stonebridge PA, Kelman
J, et al. Above-knee femoropopliteal bypass grafts and
the consequences of graft failure. Ann R Coll Surg Engl 1993; 75:257-260.
14.El-Kayali AA. Polytetrafluoroethylene use for above-knee femoropopliteal bypass in
critical limb ischemia. Saudi Med J 2003; 24:669-671.
15.Albers M, Romiti M, Brochado-Neto
FC, et al.
Meta-analysis of alternate autologous vein bypass grafts to
infrapopliteal arteries. J Vasc Surg 2005; 42:449-455.
16.Pedersen G, Laxdal E, Hagala M, et
al. Local
infections after above knee prosthetic femoropopliteal bypass for intermittent
claudication. Surg Infect 2004; 5:174-179.