Distal Revascularization And Interval Ligation Research Articles

Proximalization of arterial inflow for treatment of hemodialysis access-induced distal ischemia

ObjectiveHemodialysis access-induced distal ischemia (HAIDI) is a known complication of hemodialysis (HD) access. Distal revascularization and interval ligation (DRIL) is the preferred treatment for HAIDI by many surgeons. Proximalization of arterial inflow (PAI) is a promising alternative technique that, unlike DRIL, preserves the native arterial inflow. The purpose of this study is to report our experience with PAI on a series of 64 patients. MethodsThis is a single-center, retrospective cohort study of patients with both arteriovenous (AV) fistulas and grafts who underwent PAI for HAIDI from 2017 to 2023. A 4 × 7 tapered polytetrafluoroethylene (PTFE) graft was used to connect HD access inflow to the axillary artery in the majority of cases. The primary outcome of the study is resolution of HAIDI (complete, partial, or no resolution). Secondary outcomes include functional patency (primary and secondary) and 30-day complications following PAI. ResultsOf the 71 patients identified to have had PAI between May 2017 to August 2023, seven were lost to follow-up. In total, 64 patients were included, with an average age of 65 years (standard deviation, 15 years), 59.4% (38/64) female, and 37.5% (24/64) African American. The study population was notable for numerous comorbid conditions including 95.3% (61/64) hypertension; 50% (32/64) coronary artery disease; 79.7% (51/64) diabetes; and 43.8% (28/64) smoking history. Following PAI intervention for HAIDI, 55 of 64 patients (85.9%) experienced complete resolution of ischemic symptoms; five of 64 patients (7.8%) had partial resolution; two of 64 patients (3.1%) had no resolution, and two of 64 patients (3.1%) had unknown resolution. Primary patency at 1, 12, and 24 months was 94%, 81%, and 71%, respectively. Secondary patency at 1, 12, and 24 months was 97%, 87%, and 84%, respectively. The 30-day complication rate was 10.9% (7/64), with five of 64 (7.8%) thromboses, one of 64 (1.6%) thrombosis and infection, and one of 64 (1.6%) upper extremity swelling secondary to central venous stenosis (resolved with angioplasty of central venous system). Failure rate due to thrombosis at 12 and 24 months was 14% (9/64) and 15.6% (10/64), respectively. ConclusionsOur study, the largest case series of PAI to date, demonstrates that PAI is a reliable option for HAIDI intervention and has comparable safety and efficacy results to DRIL, despite the use of a synthetic graft. Furthermore, PAI has the added benefit of maintaining the native arterial pathway. Further investigation of PAI is warranted as a promising alternative to DRIL for HAIDI management.

Expected Duplex Ultrasound Results in Distal Revascularization and Interval Ligation Conduits

There are no published standards for the expected findings on noninvasive testing following distal revascularization and interval ligation (DRIL). This study evaluated the hemodynamic results and duplex ultrasound characteristics of DRIL. A retrospective chart review of patients who underwent DRIL using autogenous vein between 2008-2019 was performed. Patients with both preoperative and follow-up noninvasive testing were included. 38 patients were included in the study. Median time to first follow-up (fFU) was 30 days (range 1-226d) where 12 had complete resolution of their symptoms and 26 had partial resolution. Of the 27 patients that had pre- and post-operative testing, the wrist brachial index improved from 0.56 to 0.90 with the median finger pressure improving from 56 to 73 (p<0.001). 17 patients had a second follow-up (sFU) at a median time from DRIL of 196d (range 106-843d). There was no significant difference in WBI or FP between fFU and sFU. Duplex ultrasound of the DRIL conduits (n=32) showed a very consistent pattern with elevated median velocities proximally (inflow 235cm/s, proximal anastomosis 217.7cm/s) and distinctly slower median velocities distally (mid-conduit 46.4cm/s, distal anastomosis 78.3cm/s, outflow 59.3cm/s). The same pattern of velocities held constant at the sFU (n=16). In this study, velocities at the proximal anastomosis were significantly higher than velocities more distal in the DRIL bypass without evidence of stenosis. This may be due to hemodynamic changes in the brachial artery associated with presence of a fistula. Elevated velocities at the proximal anastomosis do not necessarily warrant further evaluation or intervention without other evidence of conduit compromise.

Expected Postoperative Duplex Ultrasound Characteristics Of Distal Revascularization And Interval Ligation

There are no published standards for the expected findings on noninvasive testing following distal revascularization and interval ligation (DRIL). This study evaluated the hemodynamic RESULTS and duplex ultrasound characteristics of DRIL.

POS-562 ISCHEMIC DISTAL HAND STEAL SYNDROME : A RARE COMPLICATION OF AVF

Ischemic steal syndrome is a rare complication of arteriovenous fistula creation due to high blood flow in a low resistance vein and reversal of flow away from the higher resistance distal arterial bed into the vein. Several options including ligation of arteriovenous fistula, banding, proximalization of arterial inflow and distal revascularization and interval ligation (DRIL).

Distal Revascularization and Interval Ligation for Dialysis Access-Related Ischemia Is Best Performed Using Arm Vein Conduit

Distal Revascularization and Interval Ligation for Dialysis Access-Related Ischemia Is Best Performed Using Arm Vein Conduit

Operative Techniques to Prevent Dialysis Access-associated Steal Syndrome in High-risk Patients Undergoing Surgery for Hemodialysis Access: A Systematic Review.

Up to 10% of patients suffer from various degrees of dialysis access-associated steal syndrome (DASS) after surgery for hemodialysis access. This systematic review was conducted to find out optimal intra-operative techniques to prevent DASS in high-risk patients.This systematic review is registered with PROSPERO (2017:CRD42017060804). It was conducted at Department of Surgery, Aga Khan University Hospital, Karachi. All types of studies conducted on intra-operative techniques to prevent DASS in high-risk population (Age > 60 years, female gender, diabetes mellitus, peripheral arterial disease and previous DASS) undergoing access creation from January 1990 till April 2019 were included in the systematic review. Thorough search was conducted on Pubmed, Google Scholar and Cochrane databases to identify relevant articles. Included studies reviewed for success of various techniques to prevent dialysis access steal syndrome are summarized.Out of 125 studies in the initial search, six met the inclusion criteria. Five were retrospective case series while one was a case report. The largest study sample size was 32. All but one study had arterio-venous access creation on an arm. “Proximalization of arterial inflow” was described in three and “prophylactic distal revascularization and interval ligation (DRIL) procedure” in two studies to prevent DASS. Only one patient out of these studies developed DASS at an overall follow-up of 7-42 months.Proximalization of inflow has been reported as the most common procedure performed to prevent DASS followed by extension technique and DRIL procedure. All three procedures have satisfactory outcome with no clear superiority of one over the other.

Distal Revascularization and Interval Ligation as a Useful Option for Steal Syndrome.

Distal revascularization and interval ligation (DRIL) is considered a useful option to relieve haemodialysis access-related steal syndrome. The results of this procedure are not known in the local setup. This is a case series of patients who underwent DRIL between January 2005 and December 2015. A total of ten patients (9 females) were included in the study. All the patients presented with grade 3 steal syndrome. Seven patients had rest pain while three had tissue loss. Polytetrafluoroethylene was used in all patients as the brachio-brachial bypass graft. All patients had smooth recovery except one patient who had postoperative brachio-brachial graft thrombosis and required thrombectomy. In all the cases, access was preserved. Steal symptoms resolved completely in all patients except for two, who had partial relief of rest pain and neurological symptoms. DRIL is a safe and effective procedure for resolution of steal syndrome and in preserving access at the same time.

Distal revascularization and interval ligation (DRIL) procedure requires a long bypass for optimal inflow

Distal revascularization and interval ligation (DRIL) is commonly used to treat ischemic steal syndrome caused by arteriovenous hemodialysis access and has been associated with good outcomes. However, the literature lacks technical details of a successful intervention. We tested the hypothesis that a brachial-level arteriovenous fistula (AVF) generates a zone of low arterial blood pressure in the brachial artery near the AVF origin. We identified patients with ischemic steal syndrome caused by an AVF originating from the brachial artery level who were eligible for the DRIL procedure. All patients were studied with invasive pressure monitoring in the brachial artery at the time of digital subtraction angiography. We measured systolic, diastolic and mean arterial blood pressure at 5 cm intervals from a point in the arterial circulation 5 cm distal to the origin of the AVF and continuing proximally into the subclavian artery. Our series involved 10 patients with a mean age of 66.5 (range 53-81) years. Four patients were women and 8 had diabetes. All patients had grade 3 ischemic steal syndrome with ischemic rest pain and/or ischemic tissue loss. Mean systolic, diastolic and arterial pressures increased from the level of the AVF until central pressures were reached. Systolic blood pressure was significantly lower than central blood pressure until a level 20-25 cm proximal to the AVF. The benefits of the DRIL procedure in alleviating ischemic steal syndrome associated with hemodialysis access are best achieved with a DRIL bypass for which inflow originates at least 20-25 cm proximal to the origin of the AVF.

In vitro hemodynamic model of the arm arteriovenous circulation to study hemodynamics of native arteriovenous fistula and the distal revascularization and interval ligation procedure

Experimental modeling of arteriovenous hemodialysis fistula (AVF) hemodynamics is challenging. Mathematical modeling struggles to accurately represent the capillary bed and venous circulation. In vivo animal models are expensive and labor intensive. We hypothesized that an in vitro, physiologic model of the extremity arteriovenous circulation with provisions for AVF and distal revascularization and interval ligation (DRIL) configurations could be created as a platform for hemodynamic modeling and testing. An anatomic, upper extremity arteriovenous model was constructed of tubing focusing on the circulation from the subclavian artery to subclavian vein. Tubing material, length, diameter, and wall thickness were selected to match vessel compliance and morphology. All branch points were constructed at physiologic angles. The venous system and capillary bed were modeled using tubing and one-way valves and compliance chambers. A glycerin/water solution was created to match blood viscosity. The system was connected to a heart simulator. Pressure waveforms and flows were recorded at multiple sites along the model for the native circulation, brachiocephalic AVF configuration, and the AVF with DR without and with IL (DR no IL and DRIL). A preset mean cardiac output of 4.2 L/min from the heart simulator yielded a subclavian artery pressure of 125/55 mm Hg and a brachial artery pressure of 121/54 mm Hg with physiologic arterial waveforms. Mean capillary bed perfusion pressure was 41 mm Hg, and mean venous pressure in the distal brachial vein was 17 mm Hg with physiologic waveforms. AVF configuration resulted in a 15% decrease in distal pressure and a 65% decrease in distal flow to the hand. DR no IL had no change in distal pressure with a 27% increase in distal flow. DRIL resulted in a 3% increase in distal pressure and a 15% increase in distal flow to the hand above that of DR no IL. Flow through the DR bypass decreased from 329 mL/min to 55 mL/min with the addition of IL. Flow through the AVF for both DR no IL and DRIL was preserved. Through the construction and validation of an in vitro, pulsatile arteriovenous model, the intricate hemodynamics of AVF and treatments for ischemic steal can be studied. DR with or without IL improved distal blood flow in addition to preserving AVF flow. IL decreased the blood flow through the DR bypass itself. The findings of the AVF as a pressure sink and the relative role of IL with DR bypass has allowed this model to provide hemodynamic insight difficult or impossible to obtain in animal or human models. Further study of these phenomena with this model should allow for more effective AVF placement and maturation while personalizing treatment for associated ischemic steal. The complications of arteriovenous fistula (AVF)-associated steal with its concurrent surgical treatments have been clinically described but have relatively little published, concrete hemodynamic data. A further understanding of the underlying hemodynamics is necessary to prevent the occurrence of steal and improve treatment when it occurs. Specific objectives are to study the blood flow through an AVF with varying anatomic and physiologic parameters, determine what factors contribute to the development of arterial steal distal to an AVF, and create optimal interventions to treat arterial steal from an AVF when it occurs. The long-term goal is creation of AVF tailored to patient-specific parameters, resulting in higher rates of functional fistulas with decreases in fistula-related complications. The ability to study fluid dynamics using a unique, in vitro, upper extremity pulsatile arteriovenous circulation simulator creates the ideal platform for this work.

Prophylactic Distal Revascularization and Interval Ligation Procedure During Femoral Vein Transposition Fistula Creation in Patients at High Risk for Ischemic Complications

Femoral vein transposition arteriovenous fistula (FVt AVF) is a viable autologous option when upper extremity dialysis access sites have become compromised. High volume flow through the AVF can lead to ischemic complications, including steal syndrome (SS), and may threaten access and limb viability. Risk factors for SS include: age >60 years, female sex, diabetes, atherosclerosis, hypertension, and previous limb procedures. Two dialysis patients, who were at high risk for SS in their lower extremities as assessed during the preoperative evaluation for an elective FVt AVF, had a distal revascularization and interval ligation (DRIL) procedure concurrently performed. At 42 and 24 months from their respective surgeries, both patients are reliably using their lower extremity autologous access sites and have not developed any signs or symptoms of ischemia. DRIL may represent an effective surgical strategy that can prophylactically be used to minimize the incidence of ischemic complications during FVt AVF in carefully selected, high-risk patients.

Prediction of graft patency and mortality after distal revascularization and interval ligation for hemodialysis access-related hand ischemia

The treatment goals of access-related hand ischemia (ARHI) are to reverse symptoms and salvage the access. Many procedures have been described, but the optimal treatment strategy remains unresolved. In an effort to guide clinical decision making, this study was undertaken to document our outcomes for distal revascularization and interval ligation (DRIL) and to identify predictors of bypass patency and patient mortality. A retrospective review was performed of all patients who underwent DRIL at the University of Florida from 2002 to 2011. Diagnosis of ARHI was based primarily upon clinical symptoms with noninvasive studies used to corroborate in equivocal cases. Patient demographics, procedure-outcome variables, and reinterventions were recorded. Bypass patency and mortality were estimated using cumulative incidence and Kaplan-Meier methodology, respectively. Cumulative incidence and Cox regression analysis were performed to determine predictors of bypass patency and mortality, respectively. A total of 134 DRILs were performed in 126 patients (mean [standard deviation] age, 57 [12] years) following brachial artery-based access. The postoperative complication rate was 27% (19% wound), and 30-day mortality was 2%. The wrist-brachial index and digital brachial index increased 0.31 (0.25) and 0.25 (0.29), respectively. Symptoms resolved in 82% of patients, and 85% continued to use their access. Cumulative incidences (± standard error of the mean) of loss of primary and primary-assisted patency rates were 5%± 2% and 4%± 2% at 1 year and 22%± 5% and 18%± 5% at 5 years, respectively, with mean follow-up of 14.8 months. Univariate predictors of primary patency failure were DRIL complications (odds ratio [OR], 3.3; 95% confidence interval [CI], 1.2-8.9; P= .02), configuration other than brachiobasilic/brachiocephalic autogenous access (OR, 3.4; 95% CI, 1.4-8.3; P= .009), and two or more prior access attempts (OR, 4.1; 95% CI, 1.6-10.4; P= .004). Brachiocephalic access configuration (OR, 0.2; 95% CI, 0.04-0.8; P=.02) and autogenous vein conduit (OR, 0.2; 95% CI, 0.06-0.58; P= .004) were predictors of improved bypass patency. All-cause mortality was 28% and 79% at 1 and 5 years, respectively. Multivariable predictors of mortality were age >40 (hazard ratio [HR], 8.3; 95% CI, 2.5-33.3; P= .0004), grade 3 ischemia (HR, 2.6; 95% CI, 1.5-4.6; P= .0008), complication from DRIL (HR, 2.4; 95% CI, 1.3-4.5; P= .004), and smoking history (HR, 2.2; 95% CI, 1.3-4; P=.007). Patients with no prior access attempts had lower predicted mortality (HR, 0.5; 95% CI, 0.3-0.9; P= .02). The DRIL procedure effectively improves distal perfusion and reverses the symptoms of ARHI while salvaging the access, but the long-term survival of these patients is poor. Given the poor survival, preoperative risk stratification is critical. Patients at high risk for DRIL failure and mortality may be best served with alternate remedial procedures.

Prediction of Graft Patency and Mortality After Distal Revascularization and Interval Ligation for Hemodialysis Access-Related Hand Ischemia

The goals for management of access-related hand ischemia (ARHI) are to reverse symptoms and salvage the access. Many procedures have been described, but the optimal treatment remains unresolved. In an effort to guide clinical decision making, this study was undertaken to document our outcomes for distal revascularization and interval ligation (DRIL) and identify predictors of bypass patency and patient mortality. A retrospective review was performed of all patients who underwent DRIL (1997-2010). Bypass patency and mortality were determined using life-table analysis, and predictors were determined using univariate and multivariate analyses. A total of 132 DRILs were performed in 126 patients (59% female, 69% diabetic; mean ± SD age, 57 ± 12 years) after brachial artery-based access with a 27% (19% wound) morbidity and a 2% 30-day mortality. Mean follow-up was 15 months. The wrist/brachial and digital/brachial indices increased 0.31 ± 0.25 and 0.25 ± 0.29, respectively. Symptoms resolved in 82% of patients, and 85% were able to continue using their access. Primary and primary-assisted patency was 77% and 79% at 1 year and 68%, 70% at 5 years. Univariate predictors of patency failure were cryopreserved conduit, pre-operative ASA + Coumadin use, a nonbrachial basilic/cephalic access configuration, and two or more prior access attempts. Preoperative statin therapy, saphenous vein conduit, and brachiocephalic access were predictors of improved bypass patency (Table). Mortality was 28% at 1 year and 79% at 5 years. Multivariate predictors of mortality were composite conduit, complication from DRIL, and an indication of grade 3 ischemia. DRIL effectively improves distal perfusion and reverses the symptoms of ARHI while salvaging the access. However, given the high mortality of this patient population, preoperative risk stratification is critical for optimal utilization of this remedial strategy.

Invited commentary

This study from the University of Pittsburgh addresses an important clinical problem after hemodialysis access creation: the ischemic steal syndrome (ISS). It is one of the largest series in the literature.1Gupta N. Yuo T.H. Konig G. Dillavou E. Leers S.A. Chaer R.A. et al.Treatment strategies of arterial steal after arteriovenous access.J Vasc Surg. 2011; 54 (in press)Google Scholar The pathophysiology of ISS is worth reviewing. The magnitude of blood flow through an arteriovenous fistula is a function of the diameter of both the fistula and the donor artery. Fistulas are classified by the fistula diameter relative to that of the donor artery. Small fistulas are defined as having a diameter <75% of the diameter of the inflow artery. In small fistulas, the primary determinant of the magnitude of fistula flow is fistula resistance, which varies with the fourth power of the diameter. The natural history of small fistulas is thrombosis. Large fistulas have a diameter >75% that of the donor artery, and the magnitude of blood flow tends to be independent of fistula resistance and diameter. In large fistulas, flow is determined primarily by the relative resistances of the peripheral vascular bed, the donor artery, and the collateral circulation. Most surgically created fistulas are of the large variety in order to provide sufficient blood flow (approximately 600 ml/minute) for dialysis.2Wixon C.L. Hughes J.D. Mills J.L. Understanding strategies for the treatment of ischemic steal syndrome after hemodialysis access.J Am Coll Surg. 2000; 191: 301-310Abstract Full Text Full Text PDF PubMed Scopus (124) Google Scholar, 3Wixon C.L. Mills J.L. Berman S.S. Distal revascularization-interval ligation for maintenance of dialysis access and restoration of distal perfusion in ischemic steal syndrome.Sem Vasc Surg. 2000; 13: 77-82PubMed Google Scholar Nearly all surgically created fistulas create physiological steal; ISS results when distal arterial perfusion is inadequate to meet tissue metabolic requirements.2Wixon C.L. Hughes J.D. Mills J.L. Understanding strategies for the treatment of ischemic steal syndrome after hemodialysis access.J Am Coll Surg. 2000; 191: 301-310Abstract Full Text Full Text PDF PubMed Scopus (124) Google Scholar Thus, it is no surprise that banding, which increases fistula resistance, is unlikely to achieve the dual goals of ISS treatment (ie, preservation of the access and relief of the ischemia). In this series, banding had poor outcomes. Nineteen percent of fistulas thrombosed after banding, and 48% of patients had persistent ischemia; 73% of reinterventions were performed in patients who underwent banding. Distal revascularization and interval ligation (DRIL) had a statistically better success rate than banding (P ≤ .05) and was effective in resolution of ISS in 90% of patients. DRIL remains the procedure of choice for treatment of ISS.4Knox R.C. Berman S.S. Hughes J.D. Gentile A.T. Mills J.L. Distal revascularization-interval ligation: a durable and effective treatment for ischemic steal syndrome after hemodialysis access.J Vasc Surg. 2002; 36: 250-256Abstract Full Text PDF PubMed Scopus (153) Google Scholar I would urge future investigations of ISS to include hemodynamic data (digital arterial pressure measurements with and without fistula compression), which in my view, are essential to confirm the diagnosis and quantify severity.2Wixon C.L. Hughes J.D. Mills J.L. Understanding strategies for the treatment of ischemic steal syndrome after hemodialysis access.J Am Coll Surg. 2000; 191: 301-310Abstract Full Text Full Text PDF PubMed Scopus (124) Google Scholar While hemodynamic data were not routinely collected in this series, it is interesting to compare pre- and postoperative hemodynamics for those in whom they were available. Following the DRIL procedure, digital pressures increased from 43 to 75 mm Hg; after banding, the corresponding increase was only from 33 to 44 mm Hg. This difference was statistically significant and likely accounts for the failure of a substantial number of banded patients to improve. The authors report some experience with revision using distal inflow (RUDI) and proximalization of arterial inflow (PAI). While the reported results were excellent, patient numbers were low. These procedures likely work in a manner analogous to the DRIL procedure, by altering relative resistances (either by adding length or reducing donor artery diameter) rather than by increasing fistula outflow resistance. Such procedures, based on the physiology of ISS, are most likely to succeed. This is a well-written study of ISS. Hopefully, it will lay banding to rest. Future investigations, especially with the newer RUDI and PAI procedures, should include hemodynamic data and sufficient follow-up to allow comparison with the well-established DRIL procedure. Treatment strategies of arterial steal after arteriovenous accessJournal of Vascular SurgeryVol. 54Issue 1PreviewIschemic steal syndrome (ISS) associated with arteriovenous (AV) access is rare but can result in severe complications. Multiple techniques have been described to treat ISS with varying degrees of success. This study compares the management and success associated with these techniques. Full-Text PDF Open Archive

Huber TS, Brown MP, Seeger JM, Lee WA. Midterm outcome after the distal revascularization and interval ligation (DRIL) procedure. J Vasc Surg. 2008;48: 926-932

Huber TS, Brown MP, Seeger JM, Lee WA. Midterm outcome after the distal revascularization and interval ligation (DRIL) procedure. J Vasc Surg. 2008;48: 926-932

Distal Revascularization and Interval Ligation: A Primer for the Vascular and Interventional Radiologist

Dialysis-associated steal syndrome is a clinically significant complication associated with the creation of dialysis grafts or fistulae. The distal revascularization and interval ligation (DRIL) procedure is a surgical procedure, which has been used to treat patients with hand ischemia secondary to arterial "steal" from dialysis accesses. This article will review the dialysis-associated steal syndrome and the history, anatomy, and clinical results of the DRIL procedure.

Midterm outcome after the distal revascularization and interval ligation (DRIL) procedure

Midterm outcome after the distal revascularization and interval ligation (DRIL) procedure

Midterm outcome after the distal revascularization and interval ligation (DRIL) procedure

The distal revascularization and interval ligation (DRIL) procedure has evolved as the optimal treatment for access-related hand ischemia despite concerns about its durability. This study was designed to review our institutional experience and objectively define its mid-term outcome. A retrospective review of all patients undergoing the DRIL procedure was performed. The diagnosis of severe hand ischemia was made based primarily upon clinical presentation, but confirmed with noninvasive imaging in select cases. The DRIL conduit was selected based upon noninvasive imaging (vein conduit criteria: saphenous > arm; diameter >/=3 mm) and the proximal anastomosis was positioned >/=7 cm from the access anastomosis. The DRIL bypasses were followed in a graft surveillance protocol and remedial procedures performed as dictated by clinical or ultrasound scan findings. Sixty-four DRIL procedures were performed in 61 patients (age - 58 +/- 13 standard deviation [SD], female - 62%, diabetic - 72%). The index access procedures included: autogenous brachiocephalic - 46%, autogenous brachiobasilic - 31%, autogenous brachioaxillary translocated femoral vein - 20%, other -3%. The precipitating symptoms were pain (25%), paresthesia (34%), motor dysfunction (24%), and tissue loss (17%); a pre-emptive DRIL was performed in 5 patients. The timing of the DRIL relative to the index access was dictated by the symptoms: <24 hrs - 19%; 1 day </= DRIL </=7 days - 29%; 7 days </= DRIL </=30 days - 8%; >30 days - 44%. Perioperative mortality rate was 3% and the complication rate was 22% (wound - 14%). The DRIL procedure relieved the ischemic symptoms in 78% of the cases (residual symptoms: paresthesia - 13%; pain - 5%; tissue loss - 4%; motor - 2%). The DRIL also resulted in significant (P < .05) increases in both the wrist/brachial index (WBI) and digital/brachial index (DBI) with the mean increases of 0.34 +/- 0.26 and 0.41 +/- 0.21, respectively. The primary DRIL patency rates (+/- standard error of the mean [SEM]) were 77 +/- 8%, 74 +/- 9%, and 71 +/- 9% at 1 year, 3 years, and 5 years, respectively, while the corresponding secondary patency rates were 81 +/- 7%, 76 +/- 9%, and 76 +/- 9%, and the survival rates were 71 +/- 6%, 59 +/- 7%, and 33 +/- 9%. The index access procedure went on to mature sufficiently for cannulation in 68% of the cases when the DRIL was performed early (ie, <3 months from index access); all accesses functional at the time of the DRIL were used for dialysis throughout the perioperative period. The DRIL procedure safely and effectively relieves the symptoms of severe access-related hand ischemia while preserving the access. The midterm results suggest that the DRIL bypasses are durable, although long-term graft surveillance may be justified given the observed failures.

Intraoperative Flow Measurements Are Helpful in the Treatment of High-Inflow Steal Syndrome on a Predialysis Patient with a Brachiocephalic Fistula: A Case Report

Distal revascularization and interval ligation (DRIL) is currently one of the mainstay treatments for severe steal syndrome. However, when high inflow is the underlying cause, this technique does not fully address the problem. Here, we describe the use of intraoperative flow measurements using transit time ultrasound technology to help identify the cause of steal syndrome in a predialysis patient (no transonic surveillance) with a brachiocephalic fistula, who then was treated successfully by inflow reduction surgery using a bovine ureter graft. We believe that inflow reduction might be superior to DRIL in treating steal syndrome caused by high inflow and that transit time ultrasound might be helpful when transonic treatment is not possible.

Distal Revascularization and Interval Ligation (DRIL) Procedure for the Treatment of Ischemic Steal Syndrome after Arm Arteriovenous Fistula

The objective of this study was to investigate the efficacy of the distal-revascularization-interval ligation (DRIL) technique in alleviating symptoms of ischemic steal syndrome and in preserving hemodialysis access. A retrospective chart review was conducted of all patients receiving the DRIL procedure in a 3-year period. There were 38 DRIL bypass grafts identified in 35 patients, with 36 DRILs with follow-up adequate for analysis. Comparison of preoperative and postoperative digital pulse volume recording (PVR) data was made using the t-test. The majority of patients presented with multiple ischemic symptoms, most commonly coolness, pain, and paresthesias. Six patients presented with frank digital necrosis. The mean interval to DRIL was 4.9 months following fistula construction (range 0.1-24). In 66.7% of patients for whom complete follow-up data were available (24/36), all ischemic symptoms were alleviated by DRIL. Of the remaining 12 patients, 11 experienced partial symptom relief. One patient required digital amputation following DRIL. A comparison of pre- and post-DRIL PVRs illustrated a significant increase in these values following DRIL (P < 0.05). DRIL effectively eliminates ischemic symptoms in the majority of patients and produces a significant increase in flow to the ischemic limb. The data support the usage of DRIL as the procedure of choice in the correction of ischemic steal following arm arteriovenous fistula.