Redo Pedal Bypass Surgery after Pedal Graft Failure: Gain or Gadget?
Article Outline
Pedal bypass failure is not always associated with limb loss. Management of critical limb ischemia after failure is controversial. The aim of this study is to evaluate the results of redo bypass procedures to foot arteries in the absence of alternative tibial outflow arteries. Data of patients undergoing redo pedal bypass within a 14-year period were reviewed. The outcome after redo pedal bypass in patients whose original pedal bypass failed within 30 days versus those in patients whose original pedal bypass failed more than 30 days after the original pedal bypass were reviewed. Society for Vascular Surgery reporting standards were applied. Out of 335 pedal bypass grafts, 22 (6.6%) pedal redo bypass procedures were identified in 20 patients performed after previous pedal graft failure: 64% were male, mean age 67.7 ± 9.5 years, diabetes 90.9%, hypertension 90.9%, coronary disease 68.2%, renal disease 18.2%. Seven patients were operated for early failure and 15 for late failure (median 193 days). The graft conduit at the first operation was ipsilateral greater saphenous vein (GSV) in 18 (81.8%), alternative vein in three (13.6%), and one expanded polytetrafluoroethylene. Redo graft conduits were as follows: ipsilateral GSV in nine (40.9%), arm vein in six (27.3%), contralateral GSV in two (9.1%), “other veins” in two (9.1%), and homologous artery in three (13.6%). The same target artery was used in 81.8%, at the initial site in 54.5% and more distally in 27.3%. Redo revascularization for early failure was successful only once. Median follow-up after late redo was 23.7 months. Seven redo grafts performed after late pedal graft failure failed after a median of 115 days. The availability of adequate autologous conduit is the limiting factor for redo procedures. Lack of alternative outflow sites adds to the difficulty of target artery dissection. Redo pedal bypass surgery after early pedal bypass failure is associated with very poor patency and limb salvage. Acceptable patency and extension of limb salvage can be achieved with redo procedures for late pedal bypass failure.
Introduction
Pedal bypass surgery is a valuable and well-established treatment for ischemic foot complications, especially in diabetic patients.1, 2, 3 Pedal bypass procedures have been performed with excellent long-term results with regard to graft patency and limb salvage and low perioperative morbidity and mortality.3, 4 Early pedal bypass graft failure is associated with a high probability of limb loss, and take-back attempts appear to be unsuccessful in most circumstances.5 The outcome after late pedal bypass failure is different from that after early pedal bypass failure, and patients with no symptoms are best observed. Patients with recurrent symptoms after late pedal bypass failure may undergo redo arterial reconstruction to pedal target arteries or another tibial artery with acceptable results with regard to limb salvage.5 The outcome after redo pedal bypass is unclear. A few reports on the outcome after redo bypasses after failure of bypasses to more proximal target arteries indicate inferior outcome with regard to graft patency and limb salvage after redo arterial reconstruction.6, 7 The aim of this study was to review our experience with patients in whom a bypass to a pedal target artery failed and redo pedal bypass surgery was performed. The following study reports on the outcome after redo pedal bypass surgery performed after previous pedal bypass failure.
Methods
This study was undertaken at a university-based tertiary-care center.
Data from all patients undergoing vascular procedures at the Division of Vascular Surgery at the Vienna General Hospital were prospectively entered into a computerized vascular registry. Demographic data, indications for surgery, procedure-related details, and follow-up data were entered prospectively into the registry and reviewed in a retrospective manner. The database from January 1992 through August 2006 was reviewed. We identified 22 redo pedal bypass procedures, forming the basis for this report. The indications for redo pedal bypass surgery were related to ischemia-associated symptoms and ischemic tissue loss after failed pedal bypass surgery. The indications for the initial pedal bypass surgery and procedural details have been described previously.3 Indications for redo pedal bypass surgery were related to ischemic tissue loss after the initial pedal bypass had failed. In detail, the indication for redo pedal bypass surgery was met when (1) the initial pedal bypass had failed before complete healing of ischemic ulcers had occurred or (2) ulcers reoccurred in a stable foot any later after pedal bypass failure that was well tolerated initially. Graft patency was assessed by the attending surgeon. Limb salvage was defined as preservation of all or part of the foot, allowing patient ambulation without the need of a prosthetic aid. Each procedure was considered separately for the purpose of analysis in those patients who underwent bilateral redo procedures. All data are presented according to the revised reporting standards of the Joint Council of the Society for Vascular Surgery.8
All redo pedal bypasses were performed after a pedal bypass graft had failed, for purpose of analysis the redo pedal bypasses were devided into 2 groups: i) redo pedal bypass surgery after early pedal bypass failure, ii) redo pedal bypass surgery after late pedal bypass failure.
Early graft failure was defined as loss of graft patency at any time within 30 days. Late graft failure was defined as loss of graft patency at any time later than 30 days after surgery. The terms “early” and “late” graft failure refer to the primary pedal bypass procedure.
Follow-up
After discharge, patients were followed closely until complete healing of all surgical wounds and foot ulcers was achieved. Patients were seen every 3 months during the first year and every 6 months thereafter. During each office visit graft patency was assessed by the presence of a palpable pulse over the graft; in addition, a continuous hand-held Doppler probe was used for assessment. Routine follow-up with duplex ultrasound was performed at 6 months after redo pedal bypass surgery and annually thereafter; if a failing graft was suspected, duplex ultrasound was performed immediately. The median follow-up was 21.4 months (range 1-80.9).
Statistical Analysis
All statistical analyses were performed using the statistical software package SPSS 13.0 (SPSS Inc., Chicago, IL).
Patency and limb salvage rates were calculated using the Kaplan-Meier product limit method. Due to the small sample size, no valid statistical comparisons could be made since the standard error of the mean exceeded 10% at almost all time points.
Results
Patient Demographics
From January 1992 through August 2006, a total of 335 pedal bypass grafts were performed at the Division of Vascular Surgery at Vienna General Hospital. From our vascular registry we identified 22 (6.6%) redo arterial reconstructions to the pedal level that were performed in 20 patients after a previous pedal bypass graft had failed. These 22 redo pedal arterial reconstructions form the basis of this report.
The mean age at operation was 67.7 ± 9.5 years; 64% of the patients were male. Ninety-one percent of the study population presented with diabetes mellitus. Evidence or history of coronary artery disease was present in 68% of patients. Forty-one percent were smokers or had a history of smoking (Table I). The indications for redo pedal bypass surgery were related to ischemic tissue loss in all patients. Seven procedures (31.8%) were performed after early pedal graft failure, and 15 procedures (68.2%) were performed after late pedal graft failure. The median time to redo surgery after the initial pedal bypass procedure was 6.3 months (range 2 days to 89 months).
Table I. Clinical characteristics
| n = 22 | |
| Age (mean, years) | 67.7 ± 9.5 |
| Male gender | 63.6% (14) |
| DM | 90.9% (20) |
| HTN | 90.9% (20) |
| CAD | 68.2% (15) |
| CHF | 9.1% (2) |
| PMI | 22.7% (5) |
| CABG | 13.6% (3) |
| PTCA | 22.7% (5) |
| COPD | 13.6% (3) |
| PVS | 100% (22) |
| Renal disease | 18.2% (4) |
| On dialysis | 9.1% (2) |
| Dyslipidemia | 59.1% (13) |
| Nicotine | 40.9% (9) |
Procedure-Related Details
The inflow sites, outflow sites, and conduits used for redo pedal bypass surgery are depicted in Table II. In 11 cases (50%) a more distal inflow site (superficial femoral artery, deep femoral artery, popliteal artery) was used for redo surgery. In 54.5% (n = 12) the distal anastomosis was placed at the same anatomical site on the dorsalis pedis artery. Alternative conduits (contralateral greater saphenous vein [GSV], arm vein, lesser saphenous vein, arterial transplants) were used in 13 cases (59%). When short grafts (below-knee popliteal to pedal bypass) were performed at the initial bypass procedure, use of the ipsilateral GSV remnant was attempted (n = 9, 40.9%).9
Table II. Inflow arteries, outflow arteries, conduit
| Early failure 31.8% (n = 7) | Late failure 68.2% (n = 15) | |
|---|---|---|
| Inflow artery (same/distal/proximal) | 3/4/0 | 6/7/2 |
| Outflow artery (SS/SSdist/plantar/tarsal) | 3/2/2/0 | 9/4/1/1 |
| Conduit (iGSV/cGSV/arm/other) | 4/1/0/2a | 5/1/6/3b |
aLesser saphenous vein 1, accessory saphenous vein 1. |
bHomologous arterial transplants. |
The primary graft conduit at the initial pedal bypass procedure was ipsilateral GSV in 18 (81.8%), alternative vein in three (13.6%), and expanded polytetrafluoroethylene (ePTFE) in one (4.6%). Graft conduits for redo pedal bypass surgery included ipsilateral GSV in nine (40.9%), arm vein in six (27.3%), contralateral GSV in two (9.1%), “other veins” in two (9.1%), and homologous arterial transplants in three (13.6%).
Patency, Limb Salvage, and Patient Survival
Primary patency, limb salvage, and patient survival were calculated according to the Kaplan-Meier product limit method; since the standard error of the mean exceeded 10% at early time points, no statistical comparison of groups was made. Primary patency, limb salvage, and patient survival after early (n = 7, 31.8%) and late (n = 15, 68.2%) pedal bypass failure are presented in Fig. 1, Fig. 2, Fig. 3. The depiction of the Kaplan-Meier plots was limited to 2 years after redo pedal bypass surgery.
Fig. 1
Kaplan-Meier plot demonstrating cumulative primary patency after redo pedal bypass surgery performed after early and late pedal bypass failure (standard error of the mean >10% indicated by dashed lines).
Fig. 2
Kaplan-Meier plot demonstrating cumulative limb salvage after redo pedal bypass surgery performed after early and late pedal bypass failure (standard error of the mean >10% indicated by dashed lines).
Fig. 3
Kaplan-Meier plot demonstrating cumulative patient survival after redo pedal bypass surgery performed after early and late pedal bypass failure (standard error of the mean >10% indicated by dashed lines).
All seven redo pedal bypasses performed after early pedal bypass failure failed within 30 days. Limb salvage at 30 days was 42%; however, all patients experienced limb loss and none of the patients who underwent redo pedal bypass after early pedal graft failure kept the extremity longer than 1 year. Patient survival at 2 years was 100%. Median follow-up of this patient population was 12.5 months.
Outcome after redo pedal bypass surgery after late pedal bypass failurePrimary patency, limb salvage, and patient survival after 15 redo pedal bypasses for late pedal bypass failure were 100%, 100%, and 100% at 30 days; 51.8%, 86.7%, and 93.3% at 1 year; and 43.2%, 67.4%, and 81.6% at 2 years. Seven redo pedal grafts failed after a median of 115 days, requiring amputation in four (57.1%). Due to the small number of patients, no detailed statistical analysis could be undertaken.
Postoperative Pharmacotherapy
After pedal bypass surgery, all patients were put on aspirin, phenprocoumon Marcoumar® (Roche Pharma, Basel, Switzerland) or a combination of both drugs. The decision as to which therapeutic regimen was used was left to the discretion of the operating surgeon. After redo pedal bypass for early graft failure (n = 7), the therapeutic regimen in two (28.6%) patients was intensified; after redo pedal bypass for late graft failure (n = 15), the therapeutic regimen in nine (60%) patients was intensified. The therapeutic regimen was intensified so that either aspirin or warfarin was added to a monotherapy consisting of one of the aforementioned drugs. Due to the small number of individuals, no statistical analysis investigating the impact of the therapeutic regimen was undertaken.
Discussion
We reviewed our experience with redo pedal bypass surgery after pedal bypass graft failure. Attempts at redo pedal bypass after early pedal bypass graft failure (within 30 days after surgery) resulted in poor outcome; all seven redo pedal grafts failed within 30 days, and all limbs were lost within 1 year after redo arterial reconstruction. In our series the results after redo pedal bypass surgery performed after late pedal bypass graft failure were acceptable, with a limb salvage rate of 66.6% at 3 years. Redo procedures following distal arterial reconstructive surgery are associated with poorer results with regard to graft patency and limb salvage in general. Toursarkissian and coworkers10 reported a 50% amputation rate after late distal graft failure; their report included redo procedures to other target tibial arteries, and they found a worse outcome in diabetic patients. In our small series of 22 patients, 91% were diabetic, which is not surprising since pedal bypass surgery is performed in a predominantly diabetic patient population.3 Redo bypass grafts have been reported to have worse patency rates compared to primary bypass grafts that have not lost patency.11 Overall, the humbling results with regard to graft patency and limb salvage after redo pedal bypass surgery emphasize the importance of proper patient selection and avoidance of technical errors at the initial surgery.
A critical issue in redo distal arterial reconstructive surgery is the availability of adequate autologous conduit. We were able to use ipsilateral GSV remnants in 43% of cases, mostly after failed below-knee popliteal to pedal bypass.9 For all other procedures, alternative conduits, as depicted in Table II, were used. In more than half of our patients we had to make a compromise in the choice of conduit for the redo procedure; in three patients who underwent multiple surgeries homologous arterial transplants from cadaveric organ donors had to be used for pedal redo surgery.12
The use of arm vein as a conduit in patients with renal insufficiency is another issue of controversy since arm veins may not be available as graft material due to previous arteriovenous fistula creation. In our series two patients with dialysis-dependent renal disease underwent redo surgery. In both cases a remnant of the GSV was used successfully and arm veins could be saved for access surgery. In our experience the use of lesser saphenous vein as a conduit is not advisable in redo pedal bypass surgery in severely ischemic calves as severe wound healing problems from the vein harvest site may occur. Pedal bypass surgery is probably one of the most extreme forms of distal arterial reconstruction. Redo surgery after pedal bypass failure adds another level to the technical difficulty of the procedure; redo dissection of distal target arteries can be especially challenging (Fig. 4). Hughes and coworkers13 demonstrated in their series of 98 patients that bypasses to the plantar and tarsal arteries can be performed with acceptable patency and limb salvage rates; however, early graft failure occurs more frequently and patency and limb salvage rates are lower compared with bypasses to the dorsalis pedis artery.
Fig. 4
Completion arteriogram after redo pedal bypass to the dorsalis pedis artery; the anastomosis was placed at the same anatomical location as during the initial pedal bypass surgery. During dissection of the dorsalis pedis artery a laceration of the posterior aspect of the dorsalis pedis occurred; the defect was repaired using vein patch angioplasty.
The use of the tourniquet occlusion technique may be a helpful adjunctive measure in certain cases.14 In our experience vascular control of the popliteal artery was difficult to obtain in redo cases due to severe calcification.
The antithrombotic regimen was modified in 50% (n = 11) of our patients. Although we found no hard proof in the reviewed literature, we suggest it may be beneficial to intensify the postoperative antithrombotic regimen after redo pedal bypass surgery to improve postoperative outcome with regard to graft patency.
Attempts at redo surgery after early pedal bypass failure appear to be unsuccessful in most instances. Even if we do not present enough data to support this, we believe a poor runoff situation at initial pedal bypass surgery is responsible for the inferior results of redo pedal bypass surgery after early pedal bypass failure. From our experience, late pedal bypass failure is mostly associated with late graft degeneration and may be treated successfully with redo pedal bypass surgery.
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Presented at the Seventeenth Annual Winter Meeting of the Peripheral Vascular Surgery Society, Steamboat Springs, CO, January 26-28, 2007.
PII: S0890-5096(07)00281-6
doi:10.1016/j.avsg.2007.07.010
© 2007 Annals of Vascular Surgery Inc. Published by Elsevier Inc All rights reserved.
