Outcome of patients with pre-existing portal vein thrombosis undergoing arterialization of the portal vein during liver transplantation

Arterialization of the portal vein is being propagated as a technical possibility in liver transplant recipients with pre-existing portal vein thrombosis. In our own small series, portal vein arterialization (PVA) was carried out in four patients undergoing orthotopic liver transplantation. In three of these cases, the portal vein was anastomosed to the aorta via an interposed iliac artery, and in one case, directly to the hepatic artery. After PVA, all transplants showed regular initial function. Two patients died postoperatively after 19 and 50 days, of intra-abdominal haemorrhage and liver necrosis with thrombosis of the portal vein, respectively. A further patient had previously developed fibrosis of the liver, which led to the death of the patient 11 months after PVA. In the remaining patient, chronic rejection requiring re-transplantation developed 24 months after PVA had been performed. These unfavourable results prompt the conclusion that PVA cannot be recommended as a standard clinical procedure.

Aortomonoiliac stent-grafts for abdominal aortic aneurysm repair: association with iliofemoral crossover grafts

PURPOSE

To analyze the outcome of endovascular exclusion of abdominal aortic aneurysm (AAA) using aortomonoiliac stent-grafts.

METHODS

Fifty-seven consecutive patients (49 men; median age 70, range 56-89) with AAA >5 cm were treated in a 6-year period with the conical ELLA stent-graft. Forty-two (73.9%) patients were classified ASA (American Society of Anesthesiologists) IV and 6 as ASA V. In the majority of cases, the implantation procedure featured device delivery through the external iliac artery, transrenal placement of a bare stent in selected cases, and an iliofemoral crossover graft through a prevesical tunnel.

RESULTS

Successful deployment was achieved in 56 (98.2%) patients. Mean time to discharge was 8.7 days (range 2-125). Two patients died in the 30-day period. Nine endoleaks occurred in 8 (14%) patients; 4 required further intervention. Mean follow-up was 35.3 months (range 1-66), during which 5 patients died from unrelated causes. No late endoleak, graft occlusion, device twisting/migration, or aneurysm rupture was observed. No correlation between type I endoleaks and unfavorable proximal neck or iliac artery anatomical characteristics could be found. Primary technical and clinical success rates were 86.0% and 94.7%, respectively.

CONCLUSIONS

In this approach, the crossover graft remains in a retropubic space and consequently does not have all the disadvantages of a subcutaneously placed prosthesis. The results achieved in this group of high-risk patients support recommendation of this technique as a simple and safe alternative to bifurcated systems.

Inferior extension of the groin flap based on the descending branch of the superficial circumflex iliac artery

The authors present a groin flap which was extended inferiorly and included the descending branch of the superficial circumflex iliac artery (SCIA) as a new alternative technique. Little research has been previously done on the descending branch of the SCIA, but the authors found clinically that this small branch was consistently present, and decided to make use of it to extend the groin flap inferiorly. The procedure extending the groin flap was successfully applied in three patients, one with a degloving injury of the leg, and two with progressive hemifacial atrophy. The extended portion was elevated as an island flap based on the descending branch in the patient with the degloving injury. Results revealed that this technique added a new axial portion located on the upper median thigh to the vascular territory of the conventional groin flap, and could be used to make a two-island groin flap.

A novel microvascular approach to treatment of the high undescended testicle

A 9-year-old boy presented for evaluation of bilateral nonpalpable testes. Despite a negative human Chorionic gonadotropin (hCG) simulation test, laparoscopy found high undescended testicles on both sides. The authors report the unusual microvascular approach utilized to accomplish testicular transfer into the scrotum and discuss the diagnostic difficulties experienced in this case.

A new approach for the surgical management of unilateral iliac artery occlusive disease: the iliofemoral crossover transposition

Aortobifemoral bypass remains the standard therapy for aortoiliac occlusive disease. Extraanatomic revascularization has been considered as an acceptable alternative and provides reasonable long-term results. Because some of the causes for its failure are related to the prosthetic material used, a technique that uses autologous material and is applicable in patients with unilateral common iliac lesions was developed. Iliofemoral crossover transposition is a femorofemoral bypass procedure in which the external iliac artery is used as a graft. The procedure is easily performed and avoids the use of prosthetic materials, minimizing the risks of their related complications. Because its biologic behavior, including hemodynamic performance, has proven to be excellent, satisfactory long-term results can be anticipated.

The use of ischaemic vessels as prostheses or tissue engineering scaffolds after cryopreservation

OBJECTIVE

to evaluate the condition of organ donor arteries subjected to prolonged cold-ischaemia followed by cryopreservation, for their possible use as vascular grafts.

MATERIALS AND METHODS

fresh specimens of human iliac artery from organ donors were used as controls. These arteries were divided into two portions, one of which was cryopreserved in an automated freezer. A further group of arteries was immersed in Wisconsin solution and kept for 4 days at 4 degrees C (cold-ischaemia). After this period, the arteries were also cut into two, and one of these portions was cryopreserved. All the cryopreserved arterial segments were stored for a month and then subjected to automated gradual thawing. The thawed specimens were evaluated by light microscopy, scanning and transmission electron microscopy, immunohistochemical analysis (MMPs, elastin, CD31, von Willebrand factor) and the in situ detection of fragmented DNA (TUNEL method).

RESULTS

the most marked changes induced by cryopreservation were partial vessel deendothelialisation and morphological changes in cells of the intima that were in the process of detachment. No significant changes were observed in the medial layer, other than discrete elastic fibre fragmentation. Following cold-ischaemia, the endothelium was the most affected layer, with large denuded areas and exposure of the fibroelastic layer. Increased MMP-2 expression was also noted after cold-ischaemia. When subjected to both cold-ischaemia and cryopreservation, a large proportion of endothelial cells showed positivity for the TUNEL technique, however, no significant difference was observed between the ischaemic and the ischaemic/cryopreserved specimens.

CONCLUSIONS

prolonged cold-ischaemia causes some additional damage to the arterial wall compared to cryopreservation alone. However, the structural component of the ischaemic vessel remains in a condition that is suitable for subsequent cryopreservation and use as a vessel substitute or a scaffold for tissue engineering.

Comparison of small intestinal submucosa-covered and noncovered nitinol stents in sheep iliac arteries: a pilot study

PURPOSE

To compare the biocompatibility and performance of nitinol endografts covered externally or internally with small intestinal submucosa (SIS) with bare nitinol stents in medium-sized arteries.

MATERIALS AND METHODS

Eighteen nitinol Zilver stents were used: six externally SIS-covered endografts (ECEs), six internally SIS-covered endografts (ICEs), and six bare stents (BSs). Devices were implanted in the balloon-injured external iliac arteries (EIAs) of nine female sheep via carotid approach. Arteriograms were obtained before and after implantation and before animal sacrifice at 1, 3, and 6 months. Histologic studies of explanted specimens were performed.

RESULTS

Implantation of all BSs, ECEs, and ICEs was successful, but slight luminal narrowing of 19% +/- 5.3% (range, 12%-28%) was seen in ICEs on postimplantation angiograms. At sacrifice, all six BSs and ECEs were patent, with BSs showing a mean angiographic luminal narrowing of 8.4% +/- 7.2% (range, 0%-18%) and ECEs showing a mean angiographic luminal narrowing of 16% +/- 7.5% (range, 6.5%-26%) as a result of neointimal hyperplasia. Four ICEs showed luminal narrowing of 21% +/- 17% (range, 0%-35%) as a result of marked neointimal hyperplasia and two were occluded, one at 3 months and the other at 6 months. ECEs and BSs showed approximately 80% lumen endothelialization at 1 month, which increased to 100% at 3 and 6 months. ICEs did not show complete endothelialization.

CONCLUSION

The BS had the least vessel wall reaction. ECEs exhibited early endothelialization with early mild to moderate wall reaction decreasing at the late study stages. ICEs showed extensive wall reaction, possibly as a result of technical problems with SIS attachment.

Early results of a prospective randomized trial of spliced vein versus polytetrafluoroethylene graft with a distal vein cuff for limb-threatening ischemia

OBJECTIVE

Single-piece vein remains the conduit of choice in patients who need bypass grafting for limb salvage. When this option is not available, two of the remaining options are prosthetic bypass graft or several segments of vein spliced together. In this study, we compare spliced vein bypass grafting versus polytetrafluoroethylene grafting with a distal vein cuff in patients with limb-threatening ischemia.

METHODS

Between 1996 and 2000, 39 bypass grafting procedures in 36 patients were performed for limb-threatening ischemia. These procedures were prospectively randomized to either spliced vein bypass grafting (spliced group, 19 bypass grafts) or polytetrafluoroethylene grafting with a distal vein cuff (cuff group, 20 bypass grafts). All the patients in the cuff group underwent anticoagulation therapy with warfarin sodium after surgery. The inclusion criteria included: no single-piece vein option for bypass grafting, adequate vein for splice, no composite sequential option, and limb-threatening ischemia. The demographics were similar between the two groups.

RESULTS

The primary patency rate at 2 years was 44% and 49% for the spliced and cuff groups, respectively. In the spliced group, seven of 19 bypass grafts underwent revision in the follow-up period, and two of 20 cuffed bypass grafts were successfully revised. The secondary patency rate was 87% and 59% (P <.05), with limb salvage rates of 94% and 85% for spliced and cuff groups, respectively. Four patients in the spliced vein group needed reoperation for wound complications related to vein harvest. One polytetrafluoroethylene graft needed removal for infection. Two early mortalities occurred in the spliced group, one from myocardial infarction and one from stroke. The overall survival rate at 2 years between the two groups was 67% and 100% for the spliced and cuff groups, respectively (P <.05).

CONCLUSION

Although this is a preliminary report, it appears that both spliced vein bypass grafting and polytetrafluoroethylene bypass grafting with a distal vein cuff produce acceptable limb salvage rates. The secondary patency rate for spliced vein is better, but these bypass grafts more often need revision or reoperation for wound complications.

[Cryopreserved homografts in arterial reconstructions]

The use of cryopreserved homologous vessels (CHV) in arterial reconstructions is indicated in cases when no suitable autologous material is available and the use of prosthetic grafts is contraindicated. In the presentations authors overview their 4 years' experiences with homografts in case of aneurysms and lower limb obliterative arterial disease. Forty four CHV grafts were implanted in 41 patients from May 1997 to May 2001. Following explantation and preparation the grafts are treated in a special preservation solution containing 10% DMSO, antibiotic and antimycotic drugs. Using a cryostat the graft packages get deep frozen and are stored in fluid nitrogen, therefore these grafts are available even after years. Donor and patient data are recorded and processed following strict bacteriological examination. No postoperative immunosuppression therapy was administered. Twenty six greater saphenous veins, 12 superficial femoral arteries, 2 iliac arteries, 3 aortic bifurcations and one thoracic aorta segment were used as graft material--24 grafts were implanted in femoro-crural, 7 in distal femoro-popliteal, 2 in proximal femoro-popliteal, 2 in ilio-femoral, 2 in femoro-femoral crossover, one in aorto-femoral, 3 in bifemoral and one in aorto-aortic position. Successful redo surgery was performed in case of graft occlusion in 6 cases, 11 limbs were amputated because of failed thrombectomy. One patient underwent surgery due to a pseudoaneurysm at the diaphysis of a femoro-crural graft, this case is presented in details. The three year graft and limb patency were 23% and 64% subsequently following infrainguinal reconstructions, graft reocclusion occurred in 17 cases, 11 limbs were amputated. Eight patients died in 30 days following CHV implantations, the causes of death were septic bleeding in 4 cases, acute myocardial infarction in 2 cases and cardiorespiratory insufficiency in 2 cases. According to the authors' results and to the literature based on well defined indication use of cryopreserved homologues vessels are a good choice for vascular reconstruction in cases, when implantation of biologic material is essential for restoring circulation.

Small-bowel herniation under the infrarenal arterial conduit in a liver transplant recipient

We report a case of herniation of the entire small bowel under an infrarenal conduit 8 months after orthotopic liver transplantation. The conduit was compressed by the mesentery and developed a stricture and thrombosis. Liver revascularization was accomplished by an urgent thrombectomy, resection of the stricture, and reanastomosis of the conduit. Suspicion of this serious complication should arise in transplant recipients who present with bowel obstruction associated with liver dysfunction.

Long-term results of cryopreserved arterial allograft reconstruction in infected prosthetic grafts and mycotic aneurysms of the abdominal aorta

PURPOSE

This prospective, observational study determined the long-term outcome in patients with abdominal aortic infection (primary or prosthetic graft) who were treated with simultaneous aortic/graft excision and cryopreserved arterial allograft reconstruction.

METHODS

From April 1992 to March 2000, patients with abdominal aortic infection underwent complete or partial excision of the infected aorta/prosthetic graft and cryopreserved arterial allograft reconstruction. Arterial allografts were harvested from multiple organ donors and cryopreserved at -80 degrees C without rate-controlled freezing. The patients were observed for survival, limb salvage, persistence and/or recurrence of infection, and allograft patency. The results were calculated with life-table methods.

RESULTS

During the 8-year study period, 28 consecutive patients (27 men, 1 woman; mean age, 64 years) underwent treatment for abdominal aortic infection (23 graft infections, including 7 graft-enteric fistulas and 5 primary aortic infections). Allograft reconstruction was performed as an emergency procedure in 13 patients (46%). The mean follow-up period was 35.4 months (range, 6-101 months). The overall treatment-related mortality rate was 17.8% (17% for graft infection, 20% for primary aortic infection). The overall 3-year survival was 67%. There was no early or late amputation. There was no persistent or recurrent infection, and none of the patients received long-term (> 3 months) antibiotic therapy. Reoperation for allograft revision, excision, or replacement was necessary in four patients (17%) who were available for examination, with no reoperative perioperative death. The 3-year primary and secondary allograft patency rates were 81% and 96%, respectively.

CONCLUSION

Our experience with cryopreserved arterial allograft in the management of abdominal aortic infection suggests that this technique seems to be a useful option for treating one of the most dreaded vascular complications.

Experimental autologous substitute vascular graft for transplantation surgery

Vascular complications in liver transplantation are a major cause of graft failure and mortality. The aim of the study was to create autologous vascular graft without risk of rejection. Posterior rectus fascia sheath lined with peritoneum was used for iliac artery replacement in seven mongrel dogs. The patency was followed by palpation and Doppler ultrasound. The grafts were removed after one month. Five grafts remained patent. The Doppler showed good, relatively increased flow (median flow rate: 383 cm/sec) after one month in all of the cases. Slight increase in diameter was present in all cases. By microscopy the five patent grafts showed viable morphology, fibroblasts, smooth muscle cells and thin fibrin layer in the wall. The grafts were lined partially with a neoendothelial monolayer and a thin fibrin layer. In conclusion, this graft presents an acceptable patency rate and low thrombogenicity, and could be useful in transplantation. Further investigations are needed to study the effect of immunosuppression and rejection on long-term morphology and patency of the grafts.

Neurologic injury after endovascular stent-graft and bilateral internal iliac artery embolization for infrarenal abdominal aortic aneurysm

The authors report a rare neurologic complication after the implantation of a bifurcated stent-graft for abdominal aortic aneurysm. The stent-graft was extended to both external iliac arteries after embolization of both internal iliac arteries. The patient subsequently had weakness and numbness of both lower limbs with bowel and bladder incontinence. He probably had ischemic injury to the nerve roots or the lumbosacral plexus, which was related to extensive occlusion of their supplying arteries. The mechanism of spinal cord and neurologic ischemia after aortic stent-graft implantation is discussed.

Bypass graft to the midpopliteal artery with a combined anterior and posterior approach

PURPOSE

The medial supragenicular and infragenicular approaches to the popliteal artery were introduced almost 50 years ago and replaced the posterior approach to the popliteal artery for distal graft implantation. We review a contemporary series of bypass grafts to the midpopliteal artery by use of a combined anterior and posterior approach to evaluate its potential clinical benefits.

TECHNIQUE

After the proximal graft anastomosis is constructed, an incision is made in the popliteal fossa to access the midpopliteal artery, the graft is passed into that incision, and all but the popliteal incision is closed. The patient is turned, the midpopliteal artery dissection is completed, and the graft is anastomosed distally.

METHODS

Fifty-seven bypass grafts, implanted distally on the midpopliteal artery by this technique over a 13-year period, chosen in preference to an infragenicular bypass graft in selected patients when a supragenicular bypass was not feasible, were assessed in terms of indications for surgery, conduit type, complications, length of postoperative hospitalization, and graft patency.

RESULTS

Bypass grafting originated from the axillary artery in two cases, the common iliac artery in one case, and the femoral artery in 54 cases. The procedure was performed in five patients with a popliteal trifurcation anomaly, nine patients with a blind popliteal segment, 20 patients with limited length of autologous vein, and five patients with an above-knee graft infection requiring an alternate path for revascularization. Autologous vein was used in 35 and polytetrafluoroethylene (PTFE) in 19 bypass grafts. Three other patients had a composite sequential femoral-popliteal-tibial bypass graft, with PTFE and autologous vein. Postoperative (30 day) complications include one death (composite sequential), one stroke (PTFE), and one graft thrombosis (saphenous vein). The mean postoperative hospitalization for the last 31 patients was 4.2 +/- 3.7 days. In the autologous vein group, the 1-year primary patency rate was 87%, and the primary assisted patency rate was 94%. In the PTFE group, the 1-year primary patency rate was 72%. Two composite sequential grafts remained patent at 1 year.

CONCLUSIONS

Bypass grafting to the midpopliteal artery with a combined anterior and posterior approach offers a safe and effective option to below-knee bypass grafting when an above-knee bypass grafting is not feasible. Compared with the medial infragenicular incision, the posterior incision results in reduced morbidity rates, rapid mobilization, and early hospital discharge.

The mechanical properties of fresh and cryopreserved arterial homografts

OBJECTIVES

To assess the effect of cryopreservation on the elasticity and compliance of arterial allografts.

MATERIALS AND METHODS

Iliofemoral segments of arteries and veins harvested from multiorgan donors were divided into two groups: fresh-control, tested for 24 hours after harvesting, and cryopreserved in liquid nitrogen after pretreatment with 20% dimethylsulphoxide and stored for an average time of 22 days. Vessel wall elastic properties were evaluated from the stress-strain relationship in a specially designed test cell fixed to the Instron Universal Testing Machine.

RESULTS

The elastic modulus of the artery control group (1.54+/-0.33 MPa, n=20) was not significantly different from the cryopreserved group (1.69+/-0.61 MPa, n=15). Similarly, values for unfrozen veins (3.11+/-0.65 MPa, n=47) were not significantly different from those of frozen samples (2.71+/-0.85 MPa, n=38). Control compliance (6. 86+/-1.79x10(-5)%/Pa, for arteries; 3.84+/-0.81x10(-5)%/Pa, for veins) was similar to that of the cryopreserved group (6.66+/-1. 80x10(-5)%/Pa, for arteries; 4.16+/-1.21x10(-5)%/Pa, for veins).

CONCLUSIONS

Cryopreservation maintains the important elastic properties of arterial and venous allografts during average storage time of 22 days.

Atypical aortic coarctation with resistant hypertension treated with axilloiliac artery bypass

A 68-year-old woman was found to have atypical coarctation of the aorta, accompanied by systolic hypertension of the upper extremities despite administration of five types of antihypertensive drugs. Since the systolic hypertension was resistant to the conventional antihypertensive therapy, axilloiliac artery bypass grafting with a subcutaneous tunnel was performed to alleviate the pressure gradient. Systolic blood pressure was successfully reduced and hypertension was controlled after surgery.

Endovascular treatment of iliac limb stenoses or occlusions in 31 patients treated with the ancure endograft

PURPOSE

The authors report their experience with treatment of iliac limb complications in patients treated with the Ancure endograft with Wallstents to provide additional support and thrombolysis when needed.

MATERIALS AND METHODS

From February 1996 to October 1999, 88 patients were treated for abdominal aortic aneurysm with use of the Ancure endograft. Of the 88 devices used, 20 were tube grafts and the remaining 68 devices had a total of 130 iliac limbs (bifurcated, n = 62; aortoiliac, n = 6). After graft deployment, all patients underwent intraoperative aortography; since July 1997, intravascular ultrasound (IVUS) has also been used.

RESULTS

Thirty-one patients (46%) required treatment of 47 (36%) limbs with Wallstents. Graft narrowing was observed in 41 limbs (27 patients) with IVUS immediately after graft deployment. All were successfully treated with placement of Wallstents. Before routine use of intraoperative IVUS, three patients presented between 2 and 6 weeks postoperatively with iliac limb thrombosis. All three limbs were successfully treated with thrombolysis and Wallstent placement to correct the underlying iliac problem. Additionally, two contralateral limbs in these three patients were also noted to have stenosis and were treated with use of Wallstents. The last patient required placement of a Wallstent to treat stenosis of surgical anastomosis of the iliac limb of an aortoiliac endograft at 3 days. All Wallstent-reinforced Ancure endografts remained patent from 1 to 36 months (mean, 14 months).

CONCLUSION

After placement of an Ancure bifurcated or aortoiliac endograft, iliac limb stenosis is easily detected with use of intraoperative IVUS. Such complications can be safely corrected with Wallstent placement. Postoperative limb occlusion at the authors' institution has been eliminated with such intervention.

Management of infected peripheral bypass by selective partial graft removal and arterial homograft insertion. Two case reports

We present two cases of partial graft removal and cryopreserved arterial homograft insertion for treatment of patent axillobifemoral (AXB) polytetrafluoroethylene (PTFE) prosthesis with infection confined only to a part of the graft. In the first patient, infection was confined to the left inguinal site; in the second, there was a cutaneous fistula in the middle prosthetic thoracic tract. Neither patient presented signs of systemic sepsis and radio immunological tests were positive only in a confined tract. After surgery, both patients showed early recovery and currently (mean follow-up 21-month) they are disease-free. Selective partial graft removal appears to give satisfactory results and may reduce the risk of complications compared with total graft removal Moreover, arterial homograft shows greater resistance to infection compared to alloplastic materials, when autologous veins are not available and/or not suitable.

Implantation of a composite bifurcated cryopreserved aorto-iliac-femoral homograft in a patient with Candida albicans endocarditis

A 35 year old woman, cocaine addict, suffered Candida albicans aortic valve endocarditis complicated with embolisation of infected vegetations in the distal abdominal aorta. She underwent successful staged aortic valve replacement followed by transaortic and transfemoral thrombectomy. One month later an arteriogram disclosed partial occlusion of the left iliac artery, bilateral aneurysmal degeneration of both iliac arteries and right iliac artery-right iliac vein fistula. She was operated again, performing re-laparotomy and re-exploration. A composite bifurcated cryopreserved homograft was implanted end-to-side between the infrarenal abdominal aorta, right external iliac artery and left common femoral artery. The right iliac artery-iliac vein fistula was obliterated with suture. The patient had an uneventful recovery but a relapsing arterio-venous fistula was diagnosed by arteriography. Three months later she underwent percutaneous transluminal closure of the reopened fistula. At present, 17 months after the implantation of the homograft, the patient is symptom-free, on antifungal agents and with arteriographic and clinical evidence of a well-functioning arterial homograft.

The clinical importance and prediction of steal following femoro-femoral cross-over bypass: study of the donor iliac artery by intravascular ultrasound, arteriography, duplex scanning and pressure measurements

OBJECTIVES

to evaluate the clinical significance of the steal phenomenon following femoro-femoral bypass, and whether the addition of intravascular ultrasound (IVUS) to the established examinations of the donor iliac artery can improve the prediction of patients who will develop steal.

DESIGN

prospective study.

MATERIAL AND METHODS

twenty-eight patients, aged 73 (50-81) years, scheduled for femoro-femoral bypass surgery in the period from 1994 to 1997, had the donor iliac artery examined by single-plane arteriography, duplex scanning, IVUS and femoral-artery blood pressure measurements (FABP)+/-papaverine. Three patients were excluded due to simultaneous thromboendarterectomy (TEA) of the donor iliac artery. The clinical stage and the ankle-brachial index (ABPI) were measured pre-, postoperatively and prospectively 1, 6, 12 and 24 months after discharge.

RESULTS

two patients developed clinical steal, while an additional five had a measurable (>0.1) decline in the donor ABPI postoperatively, but no symptoms (subclinical steal). The clinical stage of the donor limb did not deteriorate further during the follow-up period (median 8 months) in these seven patients. The decline in donor ABPI correlated with the FABP and the IVUS measurements, but not to duplex scanning or arteriography. FABP after papaverine injection and IVUS examination showed equal sensitivities and and specificities.

CONCLUSION

a clinical steal phenomenon following femoro-femoral bypass surgery seems relatively uncommon, although a subclinical steal is more frequent. Both can be predicted by FABP or IVUS. Further follow-up is required to evaluate whether subclinical steal has any consequences in the long term.

Deep circumflex iliac artery as a free arterial graft for myocardial revascularization

When complete revascularization cannot be obtained with the internal thoracic artery and the other arterial grafts, the deep circumflex iliac artery (DCIA) may be an excellent alternative conduit. The deep circumflex iliac artery was used as a free graft for direct myocardial revascularization in 4 patients from January to July 1999. We describe our experience with this arterial conduit, review the anatomy of the artery, and present our harvesting technique.

Preserved vascular homograft for revascularization of pediatric liver transplant: a clinical, histological, and bacteriological study

BACKGROUND

Arterial or venous homografts are frequently implanted for vascular reconstruction in orthotopic liver transplantation (OLT). When fresh vascular homografts (VH) from the same donor were not available, VH from another donor preserved at 4 degrees C in Terasaki (Ter) solution (modified lymphocyte culture medium) were used.

METHODS

The clinical results after implantation of Ter-stored VH versus fresh VH in the revascularization of pediatric OLT were studied retrospectively. Short- and long-term follow-up of vascular patency was carried out by doppler ultrasonography in each case. A histological and bacteriological study of nonimplanted VH stored at 4 degrees C in saline (Sal), Ter and University of Wisconsin (UW) solutions for various time periods (days 0-28) was also undertaken.

RESULTS

Between 1989 and 1996, 21 iliac arteries and 21 iliac veins preserved in Ter solution (mean preservation time: 8 days; range 1-26) and 100 fresh VH (68 arteries and 32 veins) (preservation time: 8 hr, range 4-21) were used in pediatric OLT. Thrombosis rates were 0 of 21 for stored arteries vs. 7 of 68 (10%) for fresh arteries (NS) and 3 of 21 (14%) for stored veins vs. 3 of 32 (9%) for fresh veins (NS). Actuarial graft survival rates were similar in both groups. Histological analysis of stored, nonimplanted VH invariably showed endothelial destruction within 24-48 hr after procurement. The bacteriological study showed contamination rates of 14 of 25 (56%) for Sal-stored VH, 5 of 25 (20%) for UW, and 1 of 19 (5%) for Ter (Sal vs. UW and Sal vs. Ter: P<0.01; UW vs. Ter: NS).

CONCLUSIONS

Ter-preserved cadaveric VH could be safely used in OLT despite early destruction of endothelium.

Versatility of the inferior epigastric artery as an interpositional vascular graft in living-related liver transplantation

We have used the recipient inferior epigastric artery as an interpositional vascular graft in living-related liver transplantation cases with hepatic artery obstruction, enabling us to restore the arterial inflow sufficiently to the transplanted liver. The inferior epigastric artery is easy to access during abdominal surgery. Easy to harvest, it is anatomically constant and has a caliber equivalent to that of the hepatic artery. Donor site morbidity is negligible. There is no risk of rejection because of the autograft. There has been no report on the availability of the inferior epigastric artery for hepatic artery reconstruction. We consider this vessel as a good option for an arterial conduit in case of the inadequacy or thrombosis of the hepatic artery in living-related liver transplantation.

[Biomechanical study of the vasomotor system of the arterial smooth muscle after long-term cryopreservation of a human arterial graft at two different temperatures -80 and -150C]

We conducted two parallel studies on cryopreserved arterial homografts: a biomechanical study based on traction tests and a functional study coupled with a histology examination. Twenty-four arterial segments from 6 donors (2 iliac and 2 superficial femoral segments per donor) were cryopreserved at -150 degrees C and -80 degrees C. Cryopreservation lasted at least 6 months. Lengthening at rupture, the Young elasticity module, and rupture stress were calculated from the traction test. Results were significantly different depending on the preservation temperature. The functional properties of the cryopreserved arterial grafts were evaluated by studying the vasomotricity capacity of the vascular smooth muscle (VSM) and the endothelium. The expected results (direct contracture of VSM induced by PHE and endothelial dependent relaxation of VSM induced by ACH) were measured on fresh arteries. Cryopreserved arteries showed no response to physiological doses of PHE and ACH, whatever the preservation temperature. In one-third of the cases, a lower amplitude vasoconstriction was obtained using nonphysiological doses of PHE; there was no relaxation with ACH.