Outflow Vessels Research Articles

0370: Live Scanning Workshop: Leg Arteries/Bypass

Vascular surgeons are able to perform an extensive range of arterial bypass procedures to restore circulation to the lower extremity. Bypass grafts can be made of synthetic materials such as polytetrafluoroethylene (PTFE), however autogenous grafts are the best conduits currently in use as they offer the best long term patency rates. Approximately 15 to 20% of vein grafts fail within the first 5 years of implantation. Identification of vein defects prior to thrombus formation in the graft is critical, as meaningful long-term graft salvage is often not possible when thrombosis occurs. The surveillance of synthetic grafts remains debatable, however these grafts are more likely to become infected, and may lead to serious complications and graft failure. Duplex surveillance of infrainguinal arterial bypass grafts, has emerged as the technique of choice for evaluating bypass grafts, and coupled with ankle-brachial indices (ABIs) provides a crucial element to the vascular surgeon's clinical evaluation. The first evaluation of the graft should be performed within the first month of graft implantation. Subsequent examinations are carried out at 3, 6, 12 and 18 months after implantation, then if no abnormality is detected annually thereafter. An initial baseline examination includes the native inflow vessel, proximal and distal anastomosis sites, the body of the graft and native outflow vessel. Doppler provides hemodynamic information, while colour and b-mode imaging provide morphology and structural detail. During this workshop I will provide participants with a practical protocol that is used at Queensland Vascular Diagnostics. Hints, tips, criteria, pitfalls and accurate analysis will all be discussed, and detailed handouts will be available on request.

Lower-extremity Arteriovenous Access for Haemodialysis: A Systematic Review

The lower extremity is increasingly used as an access site in end-stage renal disease patients. However, reports present conflicting results, creating confusion regarding the feasibility and outcomes. Our objective is to review the available literature and analyse the patency rates and complications of various types of lower-extremity arteriovenous access. An Internet-based literature search was performed using MEDLINE to identify all published reports on lower-extremity vascular access. The analysis involved studies comprising at least 10 arteriovenous accesses with both inflow and outflow vessels in the lower extremity, and reporting on patency rates and access-related complications. The weighted mean patency rates were calculated, and the chi-square (chi(2)) test was used to evaluate the differences in the complication rates in the subgroups of patients identified. Three main types of lower-extremity vascular access were identified: the upper thigh prosthetic, the mid-thigh prosthetic and the femoral vein transposition arteriovenous access. There are limited data on saphenous vein loop grafts, which report poor results. The weighted mean primary patency rates at 12 months were 48%, 43% and 83%, respectively. The weighted mean secondary patency rates at 12 months were 69%, 67% and 93%, respectively. Access loss as a result of infection was more common in upper thigh and mid-thigh grafts than femoral vein transposition arteriovenous access (18.40%, 18.33% vs. 1.61%; P<0.05). Ischaemic complications rates were higher in autologous than prosthetic arteriovenous access (20.97% vs. 7.18%, P<0.05). Lower-extremity vascular access has acceptable results in terms of patency, with femoral vein transposition having better patency rates than femoral grafts. Autologous access is associated with less infective complications, however, at the expense of increased ischaemic complications rates. Further research with randomised trials is required to assess the outcomes of lower-extremity vascular access.

Persistent sciatic artery aneurysm treated with concomitant tibial bypass and vascular plug embolization

The presence of a persistent sciatic artery is a rare congenital vascular malformation. Complications associated with aneurysmal degeneration of this aberrant vessel include rupture, thrombosis, and embolization with obliteration of outflow vessels. We describe the case of an 82-year-old female presenting with critical limb ischemia due to embolization from a partially thrombosed persistent sciatic artery aneurysm. Successful treatment was achieved via a common femoral to posterior tibial artery bypass with the great saphenous vein and vascular plug embolization of the aneurysm.

Landmarks and Lineages in the Developing Heart

See related article, pages 1267–1274 One of the overarching concepts underpinning mammalian embryonic development is that of “regulation.” This implies that the lineage potential of a particular cell is broader than its actual fate. Although the influential experiments in this area performed by Hans Driesch in the late 1800s concerned the fate of individual embryonic blastomeres, the concept of regulative development has pervaded all aspects of embryology, overlapping with the concept of regenerative fields. In the context of the heart, a good example is that of frog embryo cells fated to form the dorsal mesocardium and dorsal pericardial (splanchnic) mesoderm but which can “regulate” and form myocardial tissue if the normal heart is injured or extirpated.1 As we delve into the molecular mechanisms of developmental processes, we understand that limitations to cell fate are often set, particularly in the embryo, by geographical or environmental parameters, such as the source and strength of a secreted inductive signal, and these may change with time. Anatomic patterns or landmarks provide vital clues to how we should think about development and indeed disease. For example, segmentation of the embryonic paraxial mesoderm into repetitive units called somites, which bear one of the main progenitor populations for the musculoskeletal system, has been widely studied and it is known that somite segmentation is controlled by a network of synchronized molecular oscillators coupled by the Delta-Notch intercellular signaling system.2 The heart has also long been considered to have a segmental prepattern based, in part, on the series of swellings and constrictions that become evident during early heart tube formation and early fate-mapping experiments suggesting that these were the precursor structures of the chambers and their flanking regions, including the atrioventricular canal (AVC). This notion has been perpetuated as fact in embryology and medical textbooks with …

Glue Embolization of a Ruptured Celiac Trunk Aneurysm

The purpose of this article is to report a case of ruptured celiac trunk aneurysm treated with glue embolization. A 39-year-old man presented with abdominal pain. Abdominal computed tomography (CT) depicted the presence of hemoperitoneum, and CT angiography revealed an aneurysm in the celiac trunk. The endovascular access into the aneurysm's outflow vessel was unattainable. N-butyl cyanoacrylate (NBCA) embolization was performed. However, untargeted distal embolizations via the left gastric, splenic, and common hepatic arteries formed. Postembolization angiography showed total occlusion of the aneurysmal cavity and left gastric artery but regular retrograde filling of the stomach, liver, and spleen by branches originating from the superior mesenteric artery. After discharge on day 6, the patient was doing well, without complications at the 11-month follow-up. The operative mortality of ruptured celiac trunk aneurysm is very high. Glue embolization was successfully used as a treatment option and should be considered when there are no other options.

Acute Limb Ischemia Due to Popliteal Artery Aneurysm: A Continuing Surgical Challenge

Up to 50% of all popliteal artery aneurysms (PAA) present with acute limb ischemia (ALI). ALI due to PAA is a difficult surgical problem, with a 20% to 60% incidence of limb loss and up to 12% mortality reported in the literature in the last three decades. Imminent limb threat requires emergency infrainguinal reconstruction, preferably with autogenous conduit. ALI due to PAA is limb-threatening, often due to obliteration of the tibial vessels in addition to thrombosis of the PAA itself. Arteriography is needed to define inflow vessel and outflow vessel anatomy followed by thrombectomy of the run-off vasculature to establish an appropriate target for bypass. Patients without evidence of neurologic deficit are best served by formal arteriography. Intraarterial thrombolysis is used to establish an outflow vessel for bypass if no runoff vessels are visible. In general, emergency operations are associated with inferior patency and limb salvage compared to elective procedures. Endovascular exclusion of PAA with covered stent graft is used increasingly in the elective setting and has been reported in patients presenting with limb ischemia. The following discussion outlines our algorithm in managing ALI from PAA and reviews management decisions and results of treatment.

Stage-Specific Control of Neural Crest Stem Cell Proliferation by the Small Rho GTPases Cdc42 and Rac1

The neural crest (NC) generates a variety of neural and non-neural tissues during vertebrate development. Both migratory NC cells and their target structures contain cells with stem cell features. Here we show that these populations of neural crest-derived stem cells (NCSCs) are differentially regulated by small Rho GTPases. Deletion of either Cdc42 or Rac1 in the NC results in size reduction of multiple NC target structures because of increased cell-cycle exit, while NC cells emigrating from the neural tube are not affected. Consistently, Cdc42 or Rac1 inactivation reduces self-renewal and proliferation of later stage, but not early migratory NCSCs. This stage-specific requirement for small Rho GTPases is due to changes in NCSCs that, during development, acquire responsiveness to mitogenic EGF acting upstream of both Cdc42 and Rac1. Thus, our data reveal distinct mechanisms for growth control of NCSCs from different developmental stages.

Atherosclerotic Peripheral Vascular Disease Symposium II

Percutaneous intervention for peripheral artery disease has evolved from balloon angioplasty for simple focal lesions to multimodality techniques that enable treatment of severe arterial insufficiency. This technological expansion comes without a standard approach or algorithm, which makes the decision-making process more subjective than objective. Nevertheless, clinical tools are available that can have a favorable effect on patient care, and these promote usage. So, when are standard endovascular techniques (such as balloon and stents) good enough, and when are the latest advances (eg, atherectomy, drug-eluting stents) more appropriate? This section will address these questions for acute limb ischemia (ALI) and chronic critical limb ischemia (CLI). It will also delineate the problem of restenosis, particularly of the superficial femoral artery (SFA), and describe treatment alternatives. The discussion will review the role of drug-eluting stents, atherectomy devices, reentry catheters, and brachytherapy, as well as their potential complications and appropriate remedies. Treatment algorithms for aortoiliac and infrainguinal disease are provided in Figures 1 through 3⇓⇓. Figure 1. Treatment algorithm for acute lower-limb ischemia. *Short infusion of thrombolytic therapy proximal to occlusion can be used to facilitate wire traversal. Figure 2. Simplified treatment algorithm for symptomatic aortoiliac disease in patients deemed candidates for revascularization. In patients with multilevel disease, the aortoiliac segment should be addressed first. TASC indicates TransAtlantic Inter-Society Consensus; AI, aortoiliac; PTA, percutaneous transluminal angioplasty; PE, physical examination; ABI, ankle-brachial index; and U/S, ultrasound. Figure 3. Simplified treatment algorithm for symptomatic infrainguinal peripheral arterial disease, assuming concomitant aortoiliac disease has been treated and the patient is an acceptable candidate for revascularization. *Alternative therapies to PTA include cryotherapy, atherectomy (directional, rotational, ablative), and cutting balloon. †Alternative stent options include stent (graft, balloon expanding, and self expanding) and drug-eluting stent. PTA indicates percutaneous transluminal angioplasty; TASC, TransAtlantic Inter-Society Consensus; PE, physical examination; …

Pushable springcoil embolization of pseudoaneurysms caused by gluteal stab injuries

Purpose To retrospectively review the outcomes of 21 patients with stab wounds to the gluteal region who underwent embolization for pseudoaneurysms causing active bleeding. Materials and methods Between 1997 and 2007, 3 superior gluteal artery, 2 inferior gluteal artery and 16 deep femoral artery muscular branch pseudoaneurysms detected by digital subtraction angiography were selectively catheterized with diagnostic catheters with hydrophilic coating and embolized with pushable springcoils. 17 of the 21 pseudoaneurysms were located in a distal end of an artery where outflow vessels could not be depicted. The other 4 lesions were side wall injuries which required the placement of coils distal and proximal to the injury site. Results Embolization was successful in controlling the bleeding in all of the patients. 16 patients required 1 or 2 coils, 4 patients required 3 coils and 1 patient required 5 coils. 2 patients had femoral puncture site hematomas which resolved spontaneously. 2 patients required surgical evacuation of large gluteal hematomas following the embolization because of symptoms second to mass effect. There were no procedure related major complications or mortality. Conclusions Our experience demonstrates that pushable coil embolization is a relatively simple, effective and economic method for the embolization of pseudoaneurysms caused by penetrating gluteal injuries. Experimenting with other embolization materials does not seem to be justified.

Genetic interaction between Bmp2 and Bmp4 reveals shared functions during multiple aspects of mouse organogenesis

Vertebrate Bmp2 and Bmp4 diverged from a common ancestral gene and encode closely related proteins. Mice homozygous for null mutations in either gene show early embryonic lethality, thereby precluding analysis of shared functions. In the current studies, we present phenotypic analysis of compound mutant mice heterozygous for a null allele of Bmp2 in combination with null or hypomorphic alleles of Bmp4. Whereas mice lacking a single copy of Bmp2 or Bmp4 are viable and have subtle developmental defects, compound mutants show embryonic and postnatal lethality due to defects in multiple organ systems including the allantois, placental vasculature, ventral body wall, skeleton, eye and heart. Within the heart, BMP2 and BMP4 function coordinately to direct normal lengthening of the outflow tract, proper positioning of the outflow vessels, and septation of the atria, ventricle and atrioventricular canal. Our results identify numerous BMP4-dependent developmental processes that are also very sensitive to BMP2 dosage, thus revealing novel functions of Bmp2.

Retrograde catheterization of haemodialysis fistulae and grafts: angiographic depiction of the entire vascular access tree and stenosis treatment

The European Best Practice Guidelines on Vascular Access propose magnetic resonance angiography (MRA) of dysfunctional dialysis fistulae and grafts if visualization of the complete arterial inflow and outflow vessels is needed. In a prospective multi-centre study we determined the technical success rate of complete vascular access tree depiction by digital subtraction angiography (DSA) as an alternative to MRA. Instead of a more invasive brachial artery of femoral artery approach, we performed a retrograde catheterization of the venous outflow or graft, and stenoses were treated in connection with DSA. A catheter was advanced into the central arterial inflow after retrograde puncture of the venous outflow or graft for depiction of the complete inflow, access region and complete outflow. Access DSA through femoral artery puncture was done if the retrograde approach failed to depict the complete vascular access tree. Stenoses with a luminal diameter reduction >or=50% were treated, if possible, in connection with DSA. A total of 116 dysfunctional haemodialysis fistulae and 50 grafts were included. Retrograde DSA depicted the complete vascular tree in 162 patients (97.6%). The arteriovenous anastomosis of four fistulae could not be negotiated by a catheter. DSA demonstrated 247 significant stenoses: 30, 128 and 89 were located in the arterial inflow (12.1%), AV anastomosis and graft region (51.8%) and venous outflow (36.0%), respectively. Ten patients (6.0%) had no stenosis. Eight (4.8%), 55 (33.1%) and 33 (19.9%) patients demonstrated stenoses in only inflow, access region or outflow, respectively. Stenoses in two or three vascular territories were present in 53 (31.9%) and 7 (4.2%) patients, respectively. A technically successful endovascular intervention was obtained in 135 of the 139 patients (97.1%) who underwent angioplasty and/or stent placement. Additional sheath insertion by antegrade outflow puncture was needed in 46 patients (33.1%) for the treatment of coexisting venous outflow stenoses, located downstream from the retrograde positioned sheath. Two minor complications were observed at DSA/angioplasty. As an alternative to MRA, full retrograde DSA is safe and effective for stenosis detection and stenosis treatment. However, access evaluation by a non-invasive imaging modality such as colour duplex ultrasound will be sufficient in most cases as proximal inflow stenoses are encountered in a minority of patients. Full retrograde DSA, including complete arterial inflow depiction, may then be reserved for cases with an unsuccessful outcome following endovascular intervention of stenoses depicted at ultrasound.

Vascular actions of the prostacyclin receptor antagonist BAY 73-1449 in the portal hypertensive rat

We have investigated the actions of the postacyclin receptor antagonist BAY 73-1449 on shunt vessel development and shunt flow in the portal vein ligated portal hypertensive Wistar rat in vivo. BAY 73-1449 (0.1–1 mg/kg), given intravenously, did not significantly reduce mesenteric inflow, but significantly reduced splenic shunt vessel outflow, compared to the effects of vehicle, in anaesthetized portal vein ligated rats as measured by shunt vessel conductance. There were no differences between portal vein ligated animals treated, beginning just before portal vein ligation, with vehicle for 7 days and animals treated for 7 days with BAY 73-1449 (1–5 mg/kg, s.c.) in the degree of porto-systemic shunting, as measured by the radioactive microsphere technique in anaesthetized rats. Portal pressure was similar in animals treated with vehicle or BAY 73-1449. It is concluded that the prostacyclin receptor antagonist BAY 73-1449 can acutely reduce shunt vessel blood flow in portal hypertensive rats.

Nonoperative Active Management of Critical Limb Ischemia: Initial Experience Using a Sequential Compression Biomechanical Device for Limb Salvage

Critical limb ischemia (CLI) patients are at high risk of primary amputation. Using a sequential compression biomechanical device (SCBD) represents a nonoperative option in threatened limbs. We aimed to determine the outcome of using SCBD in amputation-bound nonreconstructable CLI patients regarding limb salvage and 90-day mortality. Thirty-five patients with 39 critically ischemic limbs (rest pain = 12, tissue loss = 27) presented over 24 months. Thirty patients had nonreconstructable arterial outflow vessels, and five were inoperable owing to severe comorbidity scores. All were Rutherford classification 4 or 5 with multilevel disease. All underwent a 12-week treatment protocol and received the best medical treatment. The mean follow-up was 10 months (SD +/- 6 months). There were four amputations, with an 18-month cumulative limb salvage rate of 88% (standard error [SE] +/- 7.62%). Ninety-day mortality was zero. Mean toe pressures increased from 38.2 to 67 mm Hg (SD +/- 33.7, 95% confidence interval [CI] 55-79). Popliteal artery flow velocity increased from 45 to 47.9 cm/s (95% CI 35.9-59.7). Cumulative survival at 12 months was 81.2% (SE +/- 11.1) for SCBD, compared with 69.2% in the control group (SE +/- 12.8%) (p = .4, hazards ratio = 0.58, 95% CI 0.15-2.32). The mean total cost of primary amputation per patient is euro29,815 ($44,000) in comparison with euro13,900 ($20,515) for SCBD patients. SCBD enhances limb salvage and reduces length of hospital stay, nonoperatively, in patients with nonreconstructable vessels.

Modeling of Antegrade and Retrograde Flow Into a Branch Artery of the Aorta:Implications for Endovascular Stent-Grafting and Extra-Anatomical Visceral Bypass

To compare antegrade and retrograde flow characteristics in a branch of a conduit under typical pulsatile pressure and flows, seeking an answer to the question: "Does it matter whether inflow to a branch vessel is antegrade or retrograde?" A model was built to simulate an abdominal aorta with a branch designed to approximate a typical renal artery. Experiments were conducted to measure the flow rates from 40- and 200-mm-long inflow conduit tubes simulating a branch with antegrade and retrograde inflow configurations. For the base case with a flush origin of the branch, the pressure difference between the main conduit and branch vessel was adjusted so that the average branch flow rate was 1.22 L/min, representing average renal artery flow. A pump produced a pulsatile 5-L/min flow of a glycerol/water solution through a tube to mimic blood flow through the aorta at a mean inlet pressure of 97 mmHg, with systolic and diastolic pressures of 121 and 78 mmHg, respectively. Computational fluid dynamics (CFD) simulations were performed for the flush, antegrade inflow, and retrograde inflow cases. The CFD-predicted flow rates at the branch vessel outlet for all 3 geometries were compared with the experiments. From the experiments, the mean time-average branch vessel outflow rate through a 40-mm conduit for the antegrade case was 1.22+/-0.01 L/min, which was the same as the retrograde case (1.21+/-0.01 L/min; within the experimental error). However, the branch vessel outflow flow rate through a 200-mm conduit for the retrograde case was 0.07 L/min lower than the antegrade. The results from the CFD model were in good agreement with the experiments. The experiments and CFD results suggest that there is negligible difference in the outflow rates to a branch vessel in antegrade and retrograde directions for 40-mm-long conduits. However, for a 200-mm conduit, the flow to a branch vessel through the retrograde path is lower than for the antegrade direction, which has implications for the insertion of branches to stent-grafts and extra-anatomical surgical bypass for visceral revascularization.

Effect of Duplex Arteriography in the Management of Acute Limb-Threatening Ischemia From Thrombosed Popliteal Aneurysms.

The role of routine use of duplex arteriography to diagnose thrombosis of popliteal artery aneurysm as a cause of acute lower extremity ischemia is investigated. In all, 109 patients (group 1) from 1994 to 1997 and 201 patients from 1998 to 2001(group 2) presenting with acute limb-threatening ischemia were studied. None of the group 1 patients underwent preoperative duplex arteriography, and no diagnosis of acute popliteal artery aneurysm thrombosis was made. Ten patients with acute ischemia due to thrombosed popliteal artery aneurysm were identified in group 2 when preoperative duplex arteriography was routinely performed. Urgent revascularization was performed based on the results of duplex arteriography. Six patients had functioning bypasses with a mean follow-up of 15.6 months. There were 3 deaths, 2 within 30 days and 1 after 2(1/2) years with functioning grafts. One patient was lost to follow-up. Routine use of duplex arteriography may provide the diagnosis and may identify the available outflow vessels for popliteal artery aneurysm.

Infrapopliteal arterial revascularization for critical limb ischemia: Is the peroneal artery at the distal third a suitable outflow vessel?

Though the peroneal artery (PA) often remains patent despite disease or occlusion of other infrapopliteal arteries, there is skepticism about using the terminal PA as the outflow tract in distal revascularizations for limb salvage, especially when a patent inframalleolar artery is available. We analyzed our experience of using the distal PA and inframalleolar or pedal branches arteries as outflow tracts in revascularizations for critical limb ischemia. Over a decade, among 651 infrapopliteal arterial reconstructions performed in 597 patients, the PA was the outflow vessel in 214, its distal third being involved in 69 vein revascularizations (study group). During the same period, 187 vein bypass grafts were performed to 179 inframalleolar and 8 pedal branches arteries (control group). Patency, limb salvage and survival rates were assessed using Kaplan-Meier life-table analysis. Complete follow-up (range, 0.1-10.2 years; mean, 5.8 years) was obtained in 245 (95.7%) patients (66 were in the study group). The distal PA was chosen as the target vessel: (1) because the proximal, mid-PA was occluded or severely diseased and no other adequate inframalleolar or pedal branches arteries were identified preoperatively (n = 30; 43.5%); (2) because an alternative inframalleolar target vessel was present but severely diseased (n = 9; 13%); (3) because of the length limitations of the available vein (n = 12; 17.4%; or (4) because of the presence of invasive infection or necrosis overlying the dorsalis pedis or posterior tibial arteries (n = 18; 26.1%). The study group was significantly younger than the control group (68 +/- 7 years vs 70 +/- 6 years, P = .039), and included significantly more patients with diabetes mellitus (65.2% vs 50.2%, P = .033) and insulin dependence (52.2% vs 37.9%, P = .041), dialysis-dependent chronic kidney disease (5.8% vs 1.1%, P = .047), and history of smoking (75.3% vs 58.2%, P = .012). None of the patients died in the perioperative period. Although the overall need for minor amputation was statistically higher in the PA group (78.2% vs 63.1%, P = .022), especially as concerns partial calcanectomy (8.7% vs 2.1%, P = .026), the proportion of wounds completely healed during the follow-up and the mean time to wound healing were comparable in the two groups. Kaplan-Meier analysis showed comparable long-term patency, limb salvage, and survival rates in the two groups. Revascularization to the distal third of the PA can achieve much the same outcome in terms of patency and limb salvage rates, wound healing rate and timing, as when other inframalleolar or pedal branches are used. The skepticism surrounding use of the terminal PA as an outflow vessel appears to be unwarranted.

Salvage of Fibular Osteocutaneous Flap With Creation of Arteriovenous Fistula

In utilizing free-tissue transfers to reconstruct complex wounds, occasionally a mismatch exists between the donor-flap inflow and the recipient vessel outflow. This occurs more often with fasciocutaneous flaps as opposed to muscle flaps due to their higher resistance. The result of this may be microvascular thrombosis within the system and ultimately flap failure. The creation of an arteriovenous fistula at the distal aspect of the flap may improve the flow dynamics and ultimately salvage the flap. We submit a case of a free osteocutaneous fibular flap used for reconstruction of an ulnar forearm defect. Due to intraoperative thrombosis as a result of flow mismatch, we were able to salvage the flap using a distal arteriovenous fistula. This fistula improved the flow dynamics of the flap by bypassing the high intraflap resistance. An arteriovenous fistula should be kept in the repertoire of the microvascular surgeon as a potential option for flap salvage.

Blood Flow in the Circle of Willis: Modeling and Calibration

A numerical model based on one-dimensional balance laws and ad hoc zero-dimensional boundary conditions is tested against experimental data. The study concentrates on the circle of Willis, a vital subnetwork of the cerebral vasculature. The main goal is to obtain efficient and reliable numerical tools with predictive capabilities. The flow is assumed to obey the Navier-Stokes equations, while the mechanical reactions of the arterial walls follow a viscoelastic model. Like many previous studies, a dimension reduction is performed through averaging. Unlike most previous work, the resulting model is both calibrated and validated against in vivo data, more precisely transcranial Doppler data of cerebral blood velocity. The network considered has three inflow vessels and six outflow vessels. Inflow conditions come from the data, while outflow conditions are modeled. Parameters in the outflow conditions are calibrated using a subset of the data through ensemble Kalman filtering techniques. The rest of the data is used for validation. The results demonstrate the viability of the proposed approach.

The basilic vein: An alternative drainage of DIEP flap in severe venous congestion

The deep inferior epigastric perforator (DIEP) flap has become a major advance in autologous breast reconstruction, offering all the advantages of free TRAM flap with less donor-site morbidity and postoperative pain. The major drawback threatening the DIEP flap procedure is venous congestion, with potential partial or complete flap loss. Many authors reported different surgical tips aiming to solve this setback, including secondary anastomosis of deep inferior superficial epigastric vein with alternative venous outflow vessels. We present a case report of a DIEP flap salvaged by an alternative venous anastomosis, after comitant veins of the primary anastomosis widely thrombosed a few hours postoperatively. A venous bypass using ipsilateral basilica vein and superficial inferior epigastric vein was fashioned.

The Role of Thrombolysis in Acute Infrainguinal Bypass Occlusion: A Prospective Nonrandomized Controlled Study

Current treatment of acute infrainguinal bypass occlusion consists of either surgical revascularization or catheter-guided intra-arterial thrombolysis with adjunctive correction of the underlying flow-limiting lesion. In maintaining long-term patency, improving the number of outflow vessels could be of utmost importance. To compare the efficiency of both thrombolysis and primary surgical revascularization and to study the effect of thrombolysis on the number of patent outflow vessels, a prospective nonrandomized study was performed. Between February 2002 and August 2003, 54 patients with 56 occluded bypasses were included. Thirty bypasses were treated with thrombolysis, 26 primarily with surgery. Thrombolysis was successful in 80% of cases, with restoration of patency of the bypass but also with doubling of the amount of patent outflow vessels; surgery was successful in 85.71% of cases. However, in only 60% of the successfully lysed bypasses no adjunctive major surgery was needed. Amputation-free survival was 87.5% 1 year after surgery and 82.6% 1 year after thrombolysis. One year after thrombolysis without adjunctive major surgery, the amputation-free survival was only 39.7%. Therefore, a strategy could be to start with thrombolysis to improve outflow followed by a new bypass, whatever the underlying causative lesions are.