[Evaluation of treatment adaptation for low response to ASA in vascular surgery]

Hintergrund

Eine verminderte antithrombozytäre Prophylaxe („Low-Response [LR]“/„high on-treatment platelet reactivity [HPR]“) mit Acetylsalicylsäure (ASS) ist mit einem erhöhten Risiko für thrombembolische Ereignisse assoziiert. Die Prävalenz einer Low-Response ist mit ca. 20 % häufig und ein Therapieregime wurde bisher noch nicht etabliert. Das Ziel dieser prospektiven Studie war es, die Effektivität eines Therapieschemas zur Therapieanpassung bei detektierter LR/HPR bei gefäßchirurgischen Patienten zu evaluieren.

Methodik

Insgesamt wurden 36 gefäßchirurgischen Patienten mit einer antithrombozytären Dauermedikation mit ASS 100 mg/Tag und einer nachgewiesenen ASS-Low-Response (ALR) in die Studie eingeschlossen. Entsprechend dem festgelegten Therapieplan wurde bei diesen Patienten eine Therapieanpassung durchgeführt und eine Kontrollaggregometrie zur Erfolgskontrolle durchgeführt. Das verwendete Therapieschema folgte dem Test-and-treat-Prinzip. Zur Beurteilung der Wirkung von ASS diente die Impedanzaggregometrie mittels Mehrelektrodenaggregometer (Multiplate).

Ergebnisse

Insgesamt konnten alle 36 Patienten erfolgreich in eine Response überführt werden. Bei 32 (88,89 %) Patienten erfolgte eine Dosiserhöhung auf 300 mg ASS, 2 (5,56 %) Patienten wurden von ASS auf Clopidogrel umgestellt. Bei weiteren 2 (5,56 %) Patienten wurde auf eine orale Antikoagulation mit Phenprocoumon aufgrund anderer Indikationen umgestellt. Blutungskomplikationen oder Nebenwirkungen traten nicht auf.

Schlussfolgerung

Das gewählte Therapieschema zur Behandlung einer Low-Response erwies sich als effektiv und sicher bei gefäßchirurgischen Patienten. Überwiegend führte eine leitliniengerechte Dosiserhöhung der Prophylaxe von 100 mg auf 300 mg ASS zu einer effektiven Thrombozytenaggregationshemmung in der Aggregometrie.

[Prevalence of acetylsalicylic acid (ASA) - low response in vascular surgery]

BACKGROUND

Research has revealed that a decreased antiplatelet effect (low response [LR]/high on-treatment platelet reactivity [HPR]) of acetylsalicylic acid (ASA) and clopidogrel is associated with an increased risk of thromboembolic events. There are extensive ASA low response (ALR) and clopidogrel low response (CLR) prevalence data in the literature, but there are only a few studies concerning vascular surgical patients. The aim of this study was to examine the prevalence and risk factors of ALR and CLR in vascular surgical patients.

MATERIALS AND METHODS

We examined n = 154 patients with an antiplatelet long-term therapy, who were treated due to peripheral artery occlusive disease (PAD) and/or arteria carotis interna stenosis (CVD). To detect an ALR or CLR, we examined full blood probes with impedance aggregometry (ChronoLog® Aggregometer model 590). Risk factors were examined by acquisition of concomitant disease, severity of vascular disease, laboratory test results and medication.

RESULTS

We found a prevalence of 19.3 % in the ALR group and of 21.1 % in the CLR group. Risk factors for ALR were an increased platelet and leucocyte count and co-medication with pantoprazole. We found no significant risk factors for a decreased antiplatelet effect of clopidogrel treatment.

CONCLUSION

The investigated prevalence for ALR and CLR are in the range of other studies, particularly based on cardiological patients. More investigations are needed to gain a better evaluation of the risk factors for HPR and to develop an effective antiplatelet therapy regime to prevent cardiovascular complications.

Pelvine Insuffizienz und Varikosis der unteren Extremität

Ziel: Patienten mit symptomatischer Varikosis, die zusätzlich klinische und/oder duplexsonographische Zeichen einer pelvinen venösen Insuffizienz (PVI) aufwiesen, erhielten eine selektive retrograde Katheter-Phlebographie der Beckenvenen. Patienten, Methode: Bei 101 Patienten (Frauen im mittleren Alter von 49,3 Jahre) wurden zwischen Oktober 1999 und Dezember 2003 die Beckenvenen selektiv dargestellt. Die rechte Femoralvene wurde unter örtlicher Betäubung punktiert, von dort aus erfolgte mit Hilfe von Angiographie-Kathetern die selektive Darstellung der Ovarialvenen sowie der Vv. iliacae internae. Das Vorhandensein und die Ausdehnung eines etwaigen Refluxes wurden erfasst und die vom Reflux betroffenen Venenabschnitte aufgezeichnet. Ergebnisse: Die retrograde selektive Phlebographie zeigte eine PVI bei 75 Patientinnen (74,2%). Die linke V. ovarica sowie die rechte V. iliaca interna waren am häufigsten von Reflux betroffen (je n = 41; 54,6%). Eine insuffiziente linke V. iliaca interna fand sich in 35 Fällen (46,6%) und eine Insuffizienz der rechten V. ovarica in drei Fällen (4%). Bei der Hälfte der Patientinnen mit einer PVI konnte ein Reflux in mehr als einem der Beckenvenen-Hauptstämme nachgewiesen werden (n = 38; 50,6%). Eine Verbindung des pelvinen Refluxes zu varikösen epifaszialen Venen in der Leistenregion oder an den Beinen war in 44 Fällen (58,6%) vorhanden. Schlussfolgerungen: Die selektive, retrograde Katheter-Phlebographie stellt eine sichere und effektive Untersuchungsmethode dar, um Reflux in den Beckenvenen nachzuweisen. Solch ein Reflux fand sich bei 75% der Patientinnen in unserem Studienkollektiv. Eine kombinierte Insuffizienz mit Reflux in mehr als einem der Beckenvenenstämme war ein häufiger Befund und in etwa 60% der Fälle wurden Varizen an den Beinen von dem pelvinen Reflux gespeist.

High ligation of the saphenofemoral junction is necessary!

Neovascularisation can compromise the success of high ligation and resection of the greater saphenous vein. Studies using duplexultrasound to classify recurrent groin veins have described rates of neovascularisation as high as 60% and raised the question whether high ligation is actually able to prevent groin recurrences. In the present study, recurrent groin veins were excised and examined histologically in order to prove whether neovascularisation is the main cause for sapheno-femoral recurrences. Patients, methods: 419 patients accounting for 458 legs with clinically symptomatic groin recurrences were included in a country-wide multicenter study. The recurrent groin veins were excised in a standardized fashion and subsequently divided into the different types of recurrence based on histopathological criteria. Results: 427 specimen (93%) were available for histopathological examination. In 69 cases (16.2%) a neovascularisation was found to be the cause of recurrence. 311 specimen (72.8%) contained a long residual stump of the greater saphenous vein, out of which 32 (7.5%) showed additional neovascularisation at the site of the ligation. In 29 cases (6.8%) a venous side branch was found to be the recurrent groin vein. 11 specimen (2.6%) did not contain any evidence of venous material and in another 7 cases (1.6%) it was not possible to clearly identify the cause of recurrence during the histo pathological workup. Conclusion: The high rates of neovascularisation described in several duplex ultrasound studies could not be confirmed in our investigation. Recurrences seem to be mainly caused by a technically incorrect initial operation which leaves a long residual stump of the saphenous vein in place. Following a technically correct high ligation, clinically relevant recurrences appear to be rare. This finding underlines the necessity of a high ligation of the saphenous vein according to current guidelines.

Extraluminale Valvuloplastie bei Stamminsuffizienz der V. saphena magna

Die extraluminale Valvuloplastie der Vena-saphenamagna- Mündungsklappe ist eine venenerhaltende operative Therapie, die bei ausgewählten Patienten mit Stamminsuffizienz der Vena saphena magna angewendet werden kann. Die Operation kann über einen kleinen Leistenschnitt durchgeführt werden. Patienten, Methoden: 50 Patienten (54 Beine), bei denen eine extraluminale Valvuloplastie der V. saphena magna-Mündungsklappe durchgeführt worden war, wurden im Schnitt 54 Monate nach dem Eingriff nachuntersucht. Die subjektiven Symptome, die Zufriedenheit mit dem Eingriff wurden erfragt und die Beine mittels Duplexsonographie und Photoplethysmographie untersucht. Ergebnisse: 85% der Patienten waren mit dem Ergebnis des Eingriffes zufrieden. Die subjektiven Beschwerden waren bei der Nachuntersuchung in allen Symptomkategorien signifikant geringer als präoperativ. Die venöse Wiederauffüllzeit war im Schnitt um 5 s verlängert, der Venendurchmesser im Mittel um 3 mm verringert. Eine inkompetente Valvuloplastie fand sich in 6 Fällen (11,1%), eine behandlungsbedürftige Rezidivvarikosis in 10 Fällen (18,5%). Schlussfolgerung: Die extraluminale Valvuloplastie liefert auch nach 5 Jahren gute Ergebnisse in Bezug auf Patientenzufriedenheit, Vermeidung der varikösen Degeneration sowie der Rate an Rezidiven. Obwohl der Langzeiterfolg dieses Verfahrens noch nicht beurteilt werden kann, könnte es bei ausgewählten Patienten eine venenerhaltende Alternative zur klassischen Strippingoperation sein.

Saphenofemorales Leistenrezidiv nach Stripping der Vena saphena magna: technischer Fehler oder Neovaskularisation?

Ziel und Methoden: In einer prospektiven Studie sollte bei Reoperationen saphenofemoraler Leistenrezidive überprüft werden, ob die Rezidive auf technische Fehler beim Ersteingriff oder auf Neovaskularisationen zurückzuführen waren. Bei 41 konsekutiven Patienten wurden an 50 Extremitäten die Leistenrezidive reseziert. Der Nachweis eines technischen Fehlers beim Ersteingriff basierte auf histologischer und immunhistochemischer Begutachtung des Resektats. Bei Darstellung genuiner Venenwand wurde von einer beim Ersteingriff unzureichend weit proximal abgesetzten Vena saphena magna ausgegangen. Ergebnis: In 32 Fällen (64%) waren technische Fehler beim Ersteingriff ursächlich für das Leistenrezidiv. Die sichere Diagnose einer Neovaskularisation ergab sich an 12 Resektaten (24%). Bei 6 weiteren Resektaten (12%) war die Neovaskularisation nicht sicher nachweisbar, aber doch wahrscheinlich. Schlussfolgerung: Saphenofemorale Leistenrezidive werden überwiegend durch vermeidbare technische Fehler beim Ersteingriff hervorgerufen. Derartige Qualitätsmängel verursachen in Deutschland alljährlich Kosten in zweistelliger Millionenhöhe.

Der lang belassene Saphenastumpf

Ziel: Nach endovenöser Hitzeablation der V. saphena magna verbleibt im Bereich der Krosse nahezu regelhaft bis zu 5 cm langer Venenstumpf unverschlossen. Aufgrund fehlender Langzeiterfahrungen ist unklar, ob sich aus dem zurückgelassenen Stumpf im Spätverlauf ein Leistenrezidiv entwickelt. Um Anhaltspunkte für den potenziellen Zeitpunkt der Rezidiventwicklung zu gewinnen, sollte bei Pat. mit histologisch gesichertem Saphenastumpfrezidiv geklärt werden, wie lange es dauerte, bis nach dem Ersteingriff Rezidiv klinisch apperent wird. Methoden: Im Rahmen einer an sieben Zentren durchgeführten Multizenterstudie wurden operativ exstirpierte Leistenrezidive histologisch klassifiziert. Die Pat. mit eindeutigem Saphenastumpfrezidiv wurden anhand eines standardisierten Fragebogens nach den ersten Rezidivzeichen befragt. Anhand der Angaben wurde das beschwerdefreie Intervall ermittelt, das Zeitraum zwischen dem Ersteingriff und dem ersten Auftreten von Rezidivzeichen kennzeichnet. Ergebnisse: Bei 251 Pat. wurde an 278 Extremitäten ein lang belassener Saphenastumpf als Ursache des Leistenrezidivs ermittelt. den meisten Pat. bestand nach dem Ersteingriff ein beschwerdefreies Intervall, das im Durchschnitt 7,4 ± 5,70 Jahre betrug. Rezidivvarizen kündigten nach durchschnittlich 6,3 ± 5,68 Jahre und Stauungsbeschwerden nach durchschnittlich 8,5 ± 5,71 Jahre das Rezidiv an. Schlussfolgerungen: Überträgt man die Erfahrungen aus operativen Therapie auf die unverschlossenen Krossestümpfe nach endovenöser Therapie, so ist frühestens nach 7–8 Jahren mit den klinischen Zeichen eines Leistenrezidivs zu rechnen. Die gegenwärtig vorhandenen Nachbeobachtungszeiten reichen nicht aus, um den Langzeitverlauf nach endovenöser Therapie beurteilen zu können.

Kontrollierte Vergleichsstudien zur endovenösen Therapie der Varikosis

Hintergrund: Die endovenösen Therapieverfahren werden von Seiten der Industrie und zum Teil von ärztlicher Seite als minimal invasive Alternative zur Stripping-Operation dargestellt. Im Zeitalter der Evidenzbasierten Me-dizin müssen derartige Bewertungen mit kontrollierten Vergleichsstudien (RCT) abgesichert sein. Ziel unserer Studie war die Überprüfung des vorhandenen Datenmaterials mit der Fragestellung, ob die Stripping-Operation tatsächlich in validen Vergleichsstudien unterlegen ist.

Methode: Die in einer Datenbank-Recherche identifizierten RCTs zur Laser- oder Radiofrequenztherapie vs. Stripping-Operation wur-den einer Qualitätsbewertung unterzogen. Darüber hinaus wurden die Parameter Schmerzhaftigkeit und Rekonvaleszenz verglichen.

Ergebnisse: Die Qualität der RCTs zur endovenösen Therapie ist schlecht. Fehlende Multi-zentrizität (83 %), zu geringe Fallzahl (83 %) und fehlender Unabhängigkeit (33 %) waren die häufigsten Qualitätsmängel. Bei den Para-metern Schmerzhaftigkeit und Rekonvaleszenz zeigten sich für die Lasertherapie keine eindeutigen Vorteile gegenüber der Stripping-Operation. Dagegen schnitt die Radiofrequenztherapie bei diesen Parametern eindeutig besser ab als die Operation.

Schlussfolgerungen: Einen validen Methodenvergleich läßt das überwiegend mangelhafte Datenmaterial derzeit nicht zu. Nach wie vor fehlen unabhängige und fallzahlstarke Studien mit multizentrischer Datenerhebung, die für die endovenösen Therapieverfahren einen eindeutigen Vorteil gegenüber der Stripping-Operation belegen können.

Validität der makroskopischen Identifikation von Neovaskulaten durch den Operateur

Die ätiologische Zuordnung saphenofemoraler Leistenrezidive erfolgt in der intraoperativen Situation anhand makroskopischer Kriterien durch den Operateur. Die Validität der makroskopischen Identifikation von Neovaskulaten wurde im Vergleich mit dem histologischen und immunhistochemischen Goldstandard ermittelt. Patienten, Methode: Bei 47 konsekutiven Patienten (Alter 57,0 ± 10,9 Jahre) wurde im Durchschnitt 12,0 ± 7,9 Jahre nach Krossektomie und Stripping der V. saphena magna an 58 Extremitäten eine Rekrossektomie vorgenommen. Anhand des intraoperativen Befundes wurde am Ende des Eingriffes die ätiologische Zuordnung des Rezidivs vorgenommen. Der Operateur unterschied zwischen: Neovaskulat (Gruppe A), kein Neovaskulat (Gruppe B) und unklar, ob A oder B (Gruppe C). Die Präparate wurden anschließend histologisch und immunhistochemisch untersucht. Die ätiologische Zuordnung erfolgte analog der makroskopischen Beurteilung in die Gruppen a, b und c. Ergebnisse: 7 der 12 (58%) histologisch/immunhistochemisch nachgewiesenen Neovaskulate wurden vom Operateur richtig erkannt. 5 (42%) wurden falsch negativ bewertet. Dagegen wurden von den 38 Rezidiven ohne Neovaskularisation 32 (84%) richtig erkannt. Falsch positiv beurteilt wurden 4 (11%) Rezidive. In 2 Fällen (5%) war die Beurteilung nicht möglich. Die Sensitivität der makroskopischen Identifikation von Neovaskulaten betrug 58,3%, die Spezifität 88,9%. Der positive prädiktive Wert betrug 63,6%, der negative prädiktive Wert 86,4%. Schlussfolgerungen: Die Validität der makroskopischen Identifikation von Neovaskulaten ist gering. Dagegen gelingt dem Operateur die Beurteilung von Nicht-Neovaskulaten mit hoher Treffsicherheit. Die ätiologische Zuordnung von saphenofemoralen Rezidiven sollte nicht allein von der makroskopischen Beurteilung durch den Operateur abhängen.

Videoskopische Ligatur der linken Vena ovarica bei pelviner venöser Insuffizienz

Bei einer 39-jährigen, mehrgebärenden Patientin mit Rezidivvarikosis an beiden Beinen wurde bei Angabe von zyklusabhängigen Becken- und Beinschmerzen unter dem Verdacht auf eine pelvine venöse Insuffizienz eine retrograde Phlebographie der Ovarial- und Beckenvenen durchgeführt. Hierbei konnte eine isolierte Insuffizienz der linken Vena ovarica nachgewiesen werden. Zur Unterbrechung des pathologischen Refluxes wurde eine videoskopische Ligatur der linken Vena ovarica durchgeführt. Postoperativ bildeten sich die Unterleibsbeschwerden und die Stauungssymptomatik an den Beinen zurück.

External valvuloplasty in the treatment of greater saphenous vein insufficiency: a five-year follow up

Objective: To present the results of external valvuloplasty of the saphenofemoral junction in selected patients with insufficiency of the greater saphenous vein after a mean follow up of 54 months.

Methods: A total of 54 legs were prospectively studied and re-examined a mean of 54 months after the operation. The severity of the patients' symptoms and their satisfaction with the procedure were recorded. Furthermore, the venous refill time, the severity of reflux and the diameter of the greater saphenous vein were recorded preoperatively and again at follow up.

Results: In 46 cases (85%) the patients were satisfied with the outcome of the procedure. At follow up, the mean severity of symptoms was significantly lower in every symptom category. The venous refill time was reduced by a mean of 5 seconds and the diameter of the greater saphenous vein was reduced by a mean of 3 mm. Reflux in the saphenofemoral junction despite the valvuloplasty was demonstrated in six legs (11.1%), and reflux in the distal saphenous trunk despite a competent valvuloplasty was seen in 18 cases (33.3%). When reflux was present at the follow-up examination, it affected a significantly shorter segment of the greater saphenous vein than preoperatively. Treatment for recurrent symptoms was necessary in 10 (18.5%) limbs.

Conclusions: External valvuloplasty of the saphenofemoral junction offers good results in terms of patient satisfaction, relief of symptoms and recurrence rate. With long-term results still pending, this vein-sparing operation might be an alternative to stripping in selected patients.

[Recanalisation therapy of deep leg and pelvic vein thrombosis]

The conservative treatment of deep leg and pelvic vein thrombosis leads to permanent damage of recanalised veins, which in cases of long distance clots as well as involvement of the pelvic level, increase the risk of developing a postthrombotic syndrome. Such subsequent damage of the deep veins can only be avoided if occluded veins are rapidly recanalised and the function of the valves is successfully reestablished. Recanalisation may consist of surgical, fibrolytic and interventional methods and aims to minimize any subsequent damage; however no potential benefit of recanalisation versus standard treatment has yet been proven by means of methodologically adequate comparative studies. Thus, the indications for recanalisation must remain strict and be founded on a thorough risk-benefit assessment.

Histopathological findings in varicose veins following bipolar radiofrequency-induced thermotherapy – results of an ex vivo experiment

Objective

To describe the histopathological changes of the vein wall caused by bipolar radiofrequency-induced thermotherapy (RFITT), and to examine influence of power and application time on the histopathological changes.

Material and methods

Twenty vein specimens atraumatically extracted near the saphenofemoral junction were treated by RFITT ex vivo. RFITT was applied with fixed (2 seconds) and varied (up to an impedance of 400 Ω) application time and increasing power (5, 10, 15, 20, 25 W). Specimens were processed histologically.

Results

RFITT induced coagulation of collagen bundles, shrinking of muscles, splitting and necrosis of the vein wall. Circumferential necrosis of intima and media was reached by a power of 20–25 W and an application time up to an impedance of 400 Ω. Only heterogeneous necrosis of intima and media in parts of the vessel was reached by lower power with long application time.

Conclusion

A homogeneous necrosis of the circumferential vein wall needs high power and sufficient application time.

Pelvic vein incompetence influences pain levels in patients with lower limb varicosity

Purpose

To detect the influence of pelvic vein incompetence (PVI) on pain levels in patients with varicosity of the lower limb.

Materials and methods

Women of child-bearing age with symptomatic primary or recurrent varicosity of the greater saphenous vein (GSV) were prospectively included in two groups depending on the presence or absence of phlebographic signs of PVI. Pain assessment was carried out with the help of a visual analogue scale (VAS).

Results

Forty women were included in the study. Nineteen of them had phlebographic evidence of PVI (group A), whereas 21 were included in the control group (group B). Patients of group A reported a higher median total pain level than patients of group B (group A median 62, range 25–100; group B median 32, range 0–100; P = 0.001). In group A, patients experienced a median level of pain of 67.2 at the lower limb in the standing position (range 40–100) versus a median of 50.3 (range 36–81) in patients of group B ( P = NS). The median level of leg pain in the sitting position was 41.2 (range 0–67) in patients of group A and 38.1 (range 0–46) in women of group B ( P = NS). Pelvic pain level in the standing position was higher ( P = NS) in patients of group A (median 72.2, range 50–91), than in women of group B (median 20.1, range 0–41). In patients of group A, statistically significant ( P = 0.0001) higher VAS scores for pelvic pain level in sitting (group = A median 67.2, range 59–71; group B median 18.1 range 0–35) were reported.

Conclusions

In a small population of patients with GSV varicosity, overall pain levels were significantly higher in a subgroup of patients with phlebographic signs of PVI. This finding suggests that the presence of PVI might influence the intensity of varicosity symptoms.

Salvage of a dialysis angioaccess by bypassing a central venous obstruction to the common femoral vein

We describe the case of a 71 year-old male patient undergoing haemodialysis who presented with severe symptoms of venous hypertension at the left upper extremity due to subclavian and innominate vein obstruction. The patient had a well functioning ispilateral angioaccess. The pain and disabling swelling of the upper extremity developed 12 months after having a radio-cephalic arteriovenous fistula performed and progressively worsened in the last two months. The patient underwent extraanatomic axillo-femoral venous bypass grafting with a 8 mm polytetrafluoroethylene graft to the ispilateral common femoral vein. The postoperative recovery was regular and the patient was discharged 6 days after surgery with a functioning bypass and relief from the venous hypertension symptoms. In this case, surgical bypassing of a central venous obstruction through an extra-anatomical pathway relieved the symptoms of venous hypertension and prolonged the use of the haemodialysis access.

Deep vein thrombosis, vena cava inferior stenosis in combination with May-Thurner syndrome

We report a case of a patient with deep vein thrombosis including the iliac vessels, after conservative therapy of the same disease at the contralateral leg in the past. Due to a beginning compartment syndrome an operative therapy was preferred. Because of a renal insufficiency a preoperative imaging could not be performed. After venous thrombectomy we found causal for the thrombosis a high grade vena cava and vena iliaca communis stenosis. We performed an interventionel therapy. The follow-up examination showed a complete asymptomatic leg, which undervent operative treatment, by unchanged continuous symptomatic contralateral leg, which undervent conservative therapy. The high grade vena cava stenosis is probably based on a unknown ascensation of the deep vein thrombosis of the contralateral leg.

Deep venous thrombosis in a patient with large uterine myomata. Case report

A 42-year-old woman was admitted with a painful swelling of the left lower limb. Computed tomography revealed an inhomogenous uterine enlargement due to multiple myomata producing a thrombotic occlusion of the left iliac veins. Surgical treatment consisted of isolated hysterectomy. During the same operation, transfemoral thrombectomy and stent implantation in the iliac vein were performed. Hysto-logic examination revealed numerous leiomyomata as well as an endometriosis. The patient recovered well and is pain-free six months after surgery. The deep venous system is still patent at follow-up. Uterine myomata rarely cause acute iliac vein thrombosis due to direct compression. This case represents an example of successful therapy using an interdisciplinary approach.

MR venography in the detection of pelvic venous congestion

PURPOSE

To investigate the feasibility of using magnetic resonance venography (MRV) to detect pelvic venous congestion (PVC).

METHODS

A prospective study of 23 female patients with signs and symptoms of PVC, who underwent duplex sonography, MRV and phlebography (P). Examinations were interpreted in a blinded fashion. Visualization of venous anatomy, presence of venous incompetence and congestion grade were evaluated. Sensitivity and specificity of MRV using P as reference were calculated.

RESULTS

MRV agreed with P in 96% (Cohen-K-value 0.646) and in 70% (K 0.555) of the cases respectively in the venous anatomy and congestion grade. Sensitivity and specificity of MRV were 88% and 67% for ovarian veins, 100% and 38% for hypogastric veins and 91% and 42% for the pelvic plexus.

CONCLUSIONS

In this prospective study MRV showed high sensitivity in the evaluation of patients with suspected PVC. Routine use of this diagnostic method requires further studies in larger patient cohorts.

Acute iliofemoral deep venous thrombosis due to giant ovarian tumor: report of a hybrid treatment

Ovarian tumors rarely cause acute iliofemoral thrombosis due to direct compression. This case represents an example of successful therapy using an interdisciplinary approach. A 37-year-old woman was admitted with a painful swelling of the left lower limb. Computed tomography revealed a giant abdominal mass originating from the left ovary producing a thrombotic occlusion of the left iliofemoral veins. Surgical treatment consisted of complete tumor removal, adnexectomy and appendectomy. During the same operation, transfemoral thrombectomy and stent implantation in the iliac vein were performed, followed by creation of an arteriovenous fistula in the left groin. Hystologic examination revealed a well-differentiated mucinous ovarian adenocarcinoma. The patient recovered well and is tumor-free 6 months after surgery. The deep venous system is still patent at follow-up. In this case, minimal surgical trauma and complete tumor as well as thrombus removal succeeded through a positive complementary interdisciplinary approach.

Symptomatisches epidurales Hämatom unter therapeutischer Heparinisierung

A 55-year-old patient with severe arterial occlusive disease underwent a femoral artery bypass operation under combined spinal-epidural anaesthesia. Platelet count and coagulation tests were normal after phenprocoumon had been discontinued. The epidural catheter was removed on day 1 while the patient was under therapeutic dose heparin. On day 2 he complained about lower back pain going down both legs and tendon reflexes were absent on the left side. Computed tomography and magnetic resonance imaging showed a lumbar epidural haematoma, which together with a previously existing protrusion of the fourth lumbar disc, compressed the cauda equina. A neurosurgical consultation recommended a conservative approach. The symptoms resolved spontaneously and the patient was discharged in good condition 12 days after the operation.

Is initial success of thrombolytic therapy with rt-PA in patients with lower limb ischemia durable? A long-term follow-up series

Background: Catheter-directed intraarterial thrombolytic therapy with rt-PA has been established as an alternative to surgery in selected patients with lower limb ischemia. The purpose of this study is to evaluate its long-term results and to try to identify patient variables influencing outcome. Patients and methods: The results of thrombolytic treatment for acute or subacute lower limb ischemia in 82 patients (51 male, 31 female) were retrospectively analysed. Clinical data (time of symptoms onset, clinical stage, type of affected vessel, anatomical localisation) as well as comorbidities were recorded. The success rate of thrombolysis as well as the incidence of adverse events was evaluated. Patients with initial success were followed up after a median of 52,5 months. Results: Thrombolytic therapy was successful in 67 cases (82%). An additional endovascular or surgical procedure was necessary in 39 of these patients (48%). The overall bleeding rate was 18% and the mortality and major amputation rate was 1%. 42 patients with early clinical success were available for follow-up. 34 of them (81%) were free of ischemic symptoms and the overall limb salvage rate was 96%. We could not identify factors significantly influencing early or long-term results, although there was a trend towards better results in patients with acute ischemia and in patients with occluded native arteries. Conclusions: Intraarterial local thrombolytic therapy has a relatively high initial success rate in selected patients with lower limb ischemia, but is associated with a significant number of bleeding complications. Furthermore, additional procedures are required in almost half the patients. Initial success is durable at the long-term in the majority of cases. Better selection of patients and refinements of the thrombolytic therapy might help to further improve results and lower the bleeding complications.

Dacron Patch Infection After Carotid Angioplasty. A Report of 6 Cases

OBJECTIVE

We describe our experience with Dacron patch infections after carotid endarterectomy (CEA).

REPORT

From 633 patients undergoing carotid endarterectomy with Dacron patching, six re-presented with prosthetic infections. In 3 of the 6 cases a neck haematoma had necessitated surgical revision after the original carotid surgery. Five patients underwent interposition vein grafting and 1 vein patch angioplasty. Postoperatively, 2 patients developed a repeat infection including the 1 patient with patch angioplasty. All patients were free of infection and neurological symptoms after a maximum follow-up of 56.5 months.

CONCLUSION

Following the development of haemorrhage or wound complications careful clinical surveillance should be carried out after carotid reconstruction.

Distal revascularization-interval ligation for the treatment of angioaccess-induced ischemia. Case report

Two cases of upper extremity ischemia due to a steal phenomenon occurring after the creation of an arterio-venous fistula (AVF) for hemodialysis access are described. A successful treatment with a brachial to brachial artery vein bypass and a ligation of the artery distal to the AVF origin (DRIL-Procedure) was performed in both cases. Complete disappearance of symptoms and healing of the ischemic lesions with maintaining of the angioaccess patency 6 months after the repair reveal that this procedure corrected the stealing.

[Clinical and functional results after transfemoral thrombectomy for iliofemoral deep venous thrombosis: a 5-year-follow-up]

PURPOSE

The optimal therapy of deep pelvic and leg venous thrombosis is still a matter of debate. The purpose of our study was to evaluate early and late results of iliofemoral thrombectomy with regard to the prevention of the development of a postthrombotic syndrome.

METHODS

Between 1996 and 2000, 57 patients underwent transfemoral venous thrombectomy for acute iliofemoral thrombosis. 30 patients were reexamined after a mean of 60.4 months. At follow-up, the patency of the venous segments as well as the development of reflux was investigated by duplex-ultrasound. Furthermore, clinical signs and symptoms of chronic venous insufficiency as well as the subjective satisfaction of the patients with the operation were recorded.

RESULTS

Postoperatively the veins of the lower leg were completely recanalized in 25 % of the cases, those of the thigh in 52.3 %. The patency rate at the level of the groin, the pelvis and the caval vein were 92.5, 86 and 100 %, respectively. At follow-up, the veins of the lower limb, the thigh and the pelvis were patent in 76.7 % each and in 73.3 % at groin-level. The caval vein was completely recanalized in all cases. Reflux occurred in 12 patients. 26.7 % of the patients showed no signs of a postthrombotic syndrome. 63.3 % had mild changes including dilated superficial veins and swelling tendency, and only in 10 % trophic skin changes were apparent. A healed or active ulceration did not occur in any case. Except one, all patients were satisfied with the results of the thrombectomy.

CONCLUSIONS

Transfemoral thrombectomy for acute iliofemoral venous thrombosis offers good early and late results in terms of preserving venous function and reducing symptoms of venous insufficiency. In our patient population, the development of a severe postthrombotic syndrome could be reduced effectively.

Laparoscopic ligation of the infrarenal vena cava in combination with transfemoral thrombin infusion: a new animal model of chronic deep venous thrombosis

OBJECTIVE

We describe a new technique to create an animal model of chronic venous thrombosis. The morphological and histological properties of the resulting thrombi are described.

METHODS

Thirteen pigs underwent laparoscopic ligation of the infrarenal vena cava in combination with transfemoral thrombin infusion. After 1, 3, 6, 9, 12 and 15 days, respectively, two animals were killed and the thrombosed vein segments were explanted. After recording their weight and dimensions, the thrombi underwent histological examination by light microscopy.

RESULTS

In all 13 cases, the procedure was completed laparoscopically and all 13 animals survived the procedure. While 12 pigs (92%) had an uneventful postoperative course, one animal died on the first postoperative night of an unknown cause. Autopsy revealed correct placing of the ligature with occlusive thrombosis of the inferior vena cava and the iliac veins in 12 animals, in one animal the ligature had been incorrectly placed around the origin of the right iliac vein with thrombosis limited to that vessel. Histological evaluation demonstrated mixed thrombi that showed increasing signs of organisation with advancing age.

CONCLUSIONS

Laparoscopic ligation of the infrarenal vena cava in combination with transfemoral thrombin infusion is a safe and reliable way to produce chronic venous thrombosis in an animal model. The resulting thrombi are comparable to human deep venous thrombosis in terms of extent, size and organisation process.

Assessment of the temperature distribution during hyperthermia treatment by isolated extremity perfusion

A finite-element model of the human leg is developed for the assessment of temperature distribution during hyperthermia treatment by isolated extremity perfusion with a heart-lung-machine. The simulation comprises the true geometry, adequate perfusion models for the different parts of the extremity circulation in normal and tumour tissue, and the numerical procedure for the solution of the partial differential heat balance equation used. The simulation is validated using both experimental physiological and clinical data, and predicts temperature distributions and courses for various modifications of the hyperthermia procedure. It is concluded that the homogeneous temperature required in combination with chemotherapy can be achieved by isolated extremity perfusion, if a good thermal insulation is applied. If temperatures >42 degrees C are required, an additional external heat source (microwaves or ultrasound) is necessary. Although these sources may produce high absorption rates, combination with extremity perfusion is useful in reducing higher temperature gradients and the danger of locally lower temperatures.

[Clinical experiences with 43 cases of laparoscopic reconstruction in aortoiliac occlusive diseases: analysis of morbidity, effectiveness and treatment results]

Between October 1995 and April 2000 we performed 30 aortic laparoscopic reconstructions and 13 procedures on the iliac vessels. Severe aortic calcifications, poor cardiac and pulmonary status, and extensive intraabdominal adhesions were considered as contraindications for the laparoscopic procedure. Operative time, conversion rate, surgical and cardiopulmonary complications were recorded for an intention- to treat-analysis. Clinical criteria and Duplex ultrasound scans were used to document the patency of the grafts. The duration of analgetic therapy, nursing care, and hospital stay characterized the postoperative recovery. Mean surgical time was 302 minutes (min) in the aortic group (Ao) and 251 min in the iliac group (Ia). Seven conversions (5 in the aortic and 2 in the iliac group) occurred for clamping problems (n = 3), aortic lesion (n = 1), iliac vein lesion (n = 1), time consuming dissection (n = 1), and suturing failure (n = 1). Cardiac morbidity rate was 6.6% (Ao) and 7.7% (Ia). Two patients suffered pulmonary complications after aortic surgery (6.6%). Mean duration of analgetic therapy was 2.4 d (Ao) and 2.5 d (Ia). Nursing care was necessary for 4.4 d (Ao) and 3.1 d (Ia). At discharge the reconstructions were patent and ischemia symptoms subsided in all cases. Mean hospital stay was 9.1 d (Ao) and 6.7 d (Ia). At follow-up after a mean interval of 5.2 months (Ao) and 8.3 mo (Ia) patency was documented in all cases. Disease progression in the adjacent native vessels (n = 3) and beyond the graft (n = 1) was revealed by ultrasound scan, requiring a further vascular procedure. In our laparoscopic experience cardiac and pulmonary morbidity proved similar to traditional vascular surgery. The advantage of the minimally invasive approach seemed to be a more comfortable recovery. However, operative time and conversion rate emphasize the technical challenge of the procedure, which should be performed only in highly selected cases.

[Intraoperative and early postoperative results after laparoscopic implantation of aortofemoral bifurcation prostheses]

PURPOSE

The evaluation of multiple intra- and early postoperative parameters in patients undergoing laparoscopic aortobifemoral bypass grafting.

METHODS

The charts of 22 patients who underwent laparoscopic aortobifemoral grafting between February 2nd, 1996 and April 30th, 1999 were retrospectively reviewed.

RESULTS

All patients were men. The mean age was 54 +/- 7.2 years with the mean body weight being 76.3 +/- 10.9 kg and the Body-Mass-Index (BMI) 23 +/- 2.8. Claudication was present in 20 patients; one patient had rest pain and one patient suffered from tissue loss. The mean Ankle-Brachial-Index (ABI) was 0.57 +/- 0.1. In four cases conversion to open technique became necessary. The mean operation time was 316 +/- 73 min and the mean aortic cross-clamp time was 73 +/- 20 min. The mean intraoperative blood-loss reached 689 +/- 461 ml. The mean duration of postoperative ventilator support was 6.0 +/- 5.8 hours and the patients left the ICU after 2.2 +/- 3.2 days. Oral intake was allowed after a mean of 2.6 +/- 2.9 days and the central venous lines were removed after 3.8 +/- 3.9 days. The administration of analgetic drugs was required for 2.9 +/- 3.9 days. The mean length of stay in the hospital was 9.6 +/- 5.5 days.

CONCLUSIONS

Laparoscopic aortobifemoral bypass grafting is feasible in a selected group of patients. Despite relatively long operation times and the use of a pneumoperitoneum, we did not encounter significant cardiopulmonary adverse effects.

[Laparoscopic aortic surgery in a swine model using a newly designed intestine retraction system]

BACKGROUND

Recently, the feasibility of laparoscopic surgery for aortic occlusive and aneurysmal disease has been demonstrated in clinical studies. However, aortic access is compromised by poor exposure of the operative field from uncontrolled bowel. Currently available retractors are inadequate. The development of new retracting instruments therefore may facilitate laparoscopic aortic surgery.

METHODS

Two paddles inserted in a polyester bilayer (mobile device, group A) or a mesh net fixed to the abdominal wall (fixed device, group B) were used to retain the bowel. Six female piglets (28-30 kg) in each group underwent laparoscopic aortic surgery.

RESULTS

Mean time to deploy the device was 22 +/- 12 min in group A and 36 +/- 34 min in group B (n.s.). Vascular surgery time averaged 60 +/- 24 min in group A and 68 +/- 16 min in group B (n.s.), the time to withdraw the nets was respectively 3.6 +/- 1.2 min and 13.5 +/- 8.2 min (p < 0.05). Total surgery time was 155 +/- 41 min vs. 174 +/- 49 min (n.s.). Two retraction failures have been registered (1 in group A and 1 in group B). No major complications were documented.

CONCLUSIONS

Both nets provided adequate exposure of the infrarenal aorta. Vascular surgery time and blood loss were similar in both groups. Nevertheless, the handling of the mobile device (group A) seemed to be more comfortable in direct comparison. The newly developed retraction devices might facilitate the performance of laparoscopic aortic surgery.

Pharmacokinetics of tissue plasminogen activator in an isolated extracorporeal circuit

PURPOSE

The aim of this study was to investigate the pharmacokinetics of tissue plasminogen activator (tPA) under the conditions of an isolated extracorporeal circuit.

METHODS

Plasma levels of tPA were measured in the perfusion solution and in central venous blood before, during, and after the perfusion in seven patients undergoing regional hyperthermic fibrinolytic perfusion with tPA in addition to surgical thrombectomy for extended deep venous thrombosis.

RESULTS

After 15 minutes of fibrinolytic perfusion, the level of tPA in the perfusion solution was 10,427 +/- 4432 ng/mL, and after 30 minutes the maximum level of 19,726 +/- 5630 ng/mL was reached. After 60 minutes when the perfusion was discontinued, tPA concentrations dropped to 15,931 +/- 4818 ng/mL. In central venous blood, tPA levels increased to a maximum of 230.7 +/- 89.6 ng/mL after 60 minutes of perfusion, which represented 1.4% of the concentration measured in the perfusion solution at the same time. With disconnection of the extracorporeal circuit, the tPA levels in central venous blood decreased rapidly and reached a level of 24.1 +/- 8.7 ng/mL after 120 minutes.

CONCLUSION

The use of regional hyperthermic fibrinolytic perfusion in the treatment of extended deep venous thrombosis makes it possible to achieve extremely high concentrations of tPA in the perfusion solution. At the same time, the entry of the fibrinolytic agent into the systemic circulation is minimized.

Newly designed retraction devices for intestine control during laparoscopic aortic surgery: a comparative study in an animal model

BACKGROUND

Recent clinical studies have demonstrated the feasibility of laparoscopic surgery for aortic occlusive and aneurysmal disease. However, transperitoneal aortic access is compromised by poor exposure in the operative field from uncontrolled bowel. The retractors that are currently available are inadequate for this task. The development of new retractors would help to facilitate laparoscopic aortic surgery.

METHODS

Six female piglets (28-30 kg) in each group underwent laparoscopy with pneumoperitoneum (12 mmHg). Exposure of the infrarenal aorta and cross-clamping were undertaken through a transperitoneal approach. Two paddles inserted in a polyester bilayer (mobile device, group A) or a mesh net fixed to the abdominal wall (fixed device, group B) were used to retain the bowel. Aortotomy and suturing were performed to mimic a vascular procedure. After bleeding was controlled, the intraabdominal pressure (IAP) was lowered to 6 mmHg, and retraction was assessed for 30 min. The main outcome measures were time to deploy the retractors, time to perform the vascular procedure, time to withdraw the devices, and total procedural time. Blood loss and frequency of retraction failure were also recorded.

RESULTS

Mean time to deploy the device was 22 +/- 12 min in group A and 36 +/- 34 min in group B (n.s.). Vascular surgery time averaged 60 +/- 24 min in group A and 68 +/- 16 min in group B (n.s.). The times to withdraw the nets were 3.6 +/- 1.2 min and 13.5 +/- 8.2 min, respectively (p < 0.05). Total surgery time was 155 +/- 41 min vs 174 +/- 49 min (n.s.). There were six retraction failures, five in group A and one in group B. When lower IAP was used, there was only one failure in each study group. Mean blood loss was <150 ml in both groups. There were no major complications.

CONCLUSIONS

Both methods provided adequate exposure of the infrarenal aorta. Vascular surgery time and blood loss were similar for both groups. The movable device proved more usable and, at lower IAP, more effective. The results of this study demonstrate effective bowel retraction for laparoscopic aortic surgery.

Laparoscopic thrombendarterectomy of the infrarenal aorta

The aim was to perform a totally laparoscopic thrombendarterectomy (TEA) of the infrarenal aorta to reduce the trauma connected to the surgical approach. A 52-year-old man was referred to our institution with severe claudication. Angiography revealed a subtotal stenosis of the infrarenal aorta. Because the lesion was not suitable for an interventional procedure, a TEA was planned. The surgery was performed through six ports using a transperitoneal approach with pneumoperitoneum. The laparoscopic TEA was carried out according to the standards of open vascular surgery. The surgery time was 285 minutes, the crossclamping lasted 105 minutes, and the blood loss was 100 mL. The angiographic and functional results were excellent. The patient experienced a rapid recovery and was discharged after 6 days. This case report shows the feasibility of totally laparoscopic TEA of the infrarenal aorta. The well-known advantages of minimally invasive techniques in abdominal surgery with regard to the decrease of surgical trauma may also be valid in aortic surgery for occlusive disease.