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Intraoperative Ultrasonography for Location of Proximal Limit of Inferior Vena Caval Thrombosis
Intraoperative Ultrasonography for Location of Proximal Limit of Inferior Vena Caval Thrombosis Pierre-Olivier Sarfati, MD, Philippe Bonnichon, MD, Denis Pariente, MD, Yves Chapuis, MD, Paris, France
Appropriate surgical management of inferior vena caval thrombosis is dependent on the proximal limit of the thrombus. Cavograms, computed tomography, or magnetic resonance imaging all have their shortcomings in locating this limit. Intraoperative ultrasonography has allowed us to determine the exact proximal limit of vena caval thrombosis in two patients, one with suprarenal thrombosis, the other with infrarenal thrombosis. In the first patient, caval interruption and clearance of the inferior vena cava was greatly enhanced by the use of this method. Intraoperative sonography is useful in the surgical treatment of thrombosis of the inferior vena cava. (Ann Vasc Surg 1991 ;5:459-461). KEY WORDS: Intraoperative ultrasonography; ultrasound; inferior vena cava thrombosis; thrombosis.
The upper or proximal limit of inferior vena caval thrombosis is often difficult to delineate with accuracy. This limit, however, is of the utmost value as a guide to appropriate surgical treatment. Three investigative techniques are classically used to assess the upper limit of thrombus: cavograms, computed t o m o g r a p h y (CT), or magnetic resonance imaging (MRI). E a c h of these techniques, however, has its shortcomings and is difficult to obtain under emergency conditions. We have recently used intraoperative sonography of the inferior vena cava (IVC) in two patients, one with suprarenal, the other with an infrarenal thrombosis.
From the Clinique Chirurgicale and the Service de Radiologie Vasculaire, HOpital Cochin, Paris, France. Reprint requests: Yves Chapuis, MD, Clinique Chirurgical, HOpital Cochin, 27, rue du Faubourg Saint-Jacques, 75014 Paris, France.
CASE REPORTS
Case No. 1 A 54-year-old man was referred for right lower limb vein thrombosis eight weeks after surgical intervention for cecal perforation. Phlebograms showed an iliofemoral clot and heparin was initiated. Twenty-four hours later, pulmonary thromboembolism occurred. The left inferior pulmonary field was found on pulmonary arteriograms to be amputated. Cavograms were obtained during the same session and showed that the clot extended in the IVC to a point 3 cm above the renal veins (Fig. 1). Operation was through a right subcostal incision. Kocher's maneuver was performed to expose the IVC. Intraoperative sonography was performed with a Scannel 300 (CGR) using a 5 mHz " T " probe. The retrohepatic vena cava was investigated transhepatically. For investigation of the infrahepatic vena cava, saline was gently poured into the abdomen to create a fluid interface. The superior limit of the thrombus was identified at the level of the inferior margin of the caudate lobe. The lobe was retracted, four caudate veins were ligated allowing clamping of the IVC above the clot. The clot was then cleared to below the ostia of the renal veins through a cavotomy.
459
460
INTRAOPERATIVE ULTRASONOGRAPHY OF IVC THROMBOSIS
ANNALS OF VASCULAR SURGERY
Fig. 2. Intraoperative ultrasonography showing longitudinal view of caval thrombosis.
Fig. 1. Preoperative cavogram showing partial thrombosis of the suprarenal inferior vena cava.
Lastly, an Adams-de Weese device was placed infrarenally. The patient made an uneventful recovery. Heparin was continued six weeks postoperatively. Asymptomatic thrombosis of the infrarenal vena cava occurred. Renal function has remained normal and the patient was well at one year.
Case No. 2 A 26-year-old woman, para one, gravida one, experienced thoracic pain, hyperpyrexia, and restlessness 24 hours after a normal delivery. The diagnosis of pulmonary thromboembolism was confirmed on phlebocavograms and pulmonary arteriograms. Low grade hematuria was found, suggesting thrombosis of the renal veins. Thrombosis of the infrarenal IVC was noted on cavograms. The upper limit of the thrombus, however, was not visualized with accuracy. Considering the young age of the patient and the hemorrhagic risk of anticoagulant therapy in the immediate postpartum period, interruption
of the IVC with evaluation of the patency of the renal veins was decided. The IVC was approached through a right subcostal incision and Kocher's maneuver. Intraoperative sonography (Figs. 2,3) showed that the vena caval thrombus remained below the renal veins. An Adams-de Weese device was clipped on the infrarenal IVC. After an uneventful postoperative course, the patient is well at two years. DISCUSSION In most cases of thrombosis of the IVC, the proximal limit of the clot is flush with the renal veins and does not extend any higher because o f the high rate of flow at their level. Nevertheless, in 5% of cases, the tip of the clot can extend beyond this limit [1]. This increases the risk of pulmonary embolism as well as the risk of thrombosis of the renal veins. Vena caval filters can be placed by the jugular route just proximal to the renal veins. Although this will certainly contribute to prevent further pulmonary embolism [2], thrombosis of the renal veins still remains possible. Intracaval devices are rarely advocated in the young subject because of lack of adequate long-term results in this setting.
VOLUME 5 N o 5 - 1991
INTRAOPERATIVE U L T R A S O N O G R A P H Y OF lVC THROMBOSIS
Fig. 3. Intraoperative uitrasonography showing transversal view of caval thrombosis.
When the thrombosis extends to the suprarenal IVC, the usual therapeutic plan is to clear the suprarenal IVC and to place an A d a m s - d e Weese device below the renal veins. Patient status, however, has to be consistent with the magnitude of this procedure, as the operation m a y be hemorrhagic [3] with the need for autotransfusion. The principal difficulty resides in the correct delineation of the u p p e r limit of the clot. Preoperative c a v o g r a m s do not always allow determination of this limit with a c c u r a c y [4]. C o m p u t e d tomography with e n h a n c e m e n t can be contributive when vascular injection of contrast medium is made through the pedal veins. H o w e v e r , when thrombosis is recent, or when contrast medium injection is made through the upper limbs, visualization of the clot can be less than optimal. Moreover, laminar renal vein flow can be responsible for false images of filling defects [5]. N u c l e a r M R I is promising because both the t h r o m b u s and IVC can be visualized in a frontal plane. This investigative method is I
461
not always available, however, and in order to avoid possible interference, there should not be any ferromagnetic material in the field of application [6]. While sonography is most often inadequate when used externally, images obtained with the p r o b e in direct contact with the IVC are accurate. Flowing blood generates hypoechoic images while coagulated blood is responsible for strong hyperechoic areas which contrast well with the adjacent media. The retrohepatic v e n a c a v a can be visualized through the hepatic p a r e n c h y m a . The infrabepatic IVC is best visualized through a saline interface. The clot is visualized as a regular hyperechoic image whose extremity is either round or flameshaped, located within an hypoechoic area corresponding to flowing blood. The upper limit of clot can be determined and the patency of the renal veins documented. As the probe is never in direct contact with the IVC, the risk of clot mobilization is reduced with this method. When the clot extends behind the liver, the IVC may be freed by successive ligations of the caudate veins. The pericaval peritoneum is incised, the liver is retracted cephalad, and the accessory hepatic veins are exposed. The IVC can be clamped just distal, rather than above, the hepatic veins. This means that there will be less hemorrhage upon opening the vena cava because the hepatic veins are excluded. These two cases illustrate that intraoperative sonography allows the surgeon to determine the upper limit of clot in IVC thrombosis. The method is reliable, accurate, and without any risk. It m a y be adapted to local anatomic conditions. We advocate the routine use of intraoperative sonography when performing infrarenal IVC interruption, REFERENCES 1. PIQUET PH, TOURNIGAND P, JOSSO B, et al. Traitement chirurgical des thromboses ilio-caves: exigences et r6sultats. In: KIEFFER E (Ed). Chirurgie de la Veine Cave InfPrieure et de ses Branches. Paris: L'Expansion Scientifique Franqaise, 1985, pp 210-216. 2. RICCO JB, CROCHET D, SEBILLOTE P, el al. Le filtre endo-cave per-cutan6 LGM: r6sultats pr6coces d'une 6tude multicentrique. Ann Chir Vasc 1988;2:242-247. 3. BRANCHEREAU A, ELIAS A, BORDEAUX J, et al. Thromboses aigues ilio-caves: traitement m6dical ou chirurgical. In: KIEFFER E (Ed). Chirurgie de la Veine Cave Inf(rieure et de ses Branches. Paris: L'Expansion Scientifique Fran~aise, 1985, pp 19%209. 4. VUJIC [, STANLEY J, TYMINSKI LJ. Computed tomography of suspectedcaval thrombosissecondaryto proximalextension of phlebitis from the leg. Radiology 1981;140:437~-41. 5. BARNES PA, BERVARDINO ME, THOMAS JL. Flow phenomenon mimicking thrombus: a possible pitfall of the pedal infusion technique. J Camput Assist Tomogr 1982:6: 304-306. 6. HRICAK H. AMPARO E. FISHER MR, et al. Abdominal venous system: assessment using MR. Radiology 1985;156: 415-422. !1 Iii
Appropriate surgical management of inferior vena caval thrombosis is dependent on the proximal limit of the thrombus. Cavograms, computed tomography, or magnetic resonance imaging all have their shortcomings in locating this limit. Intraoperative ultrasonography has allowed us to determine the exact proximal limit of vena caval thrombosis in two patients, one with suprarenal thrombosis, the other with infrarenal thrombosis. In the first patient, caval interruption and clearance of the inferior vena cava was greatly enhanced by the use of this method. Intraoperative sonography is useful in the surgical treatment of thrombosis of the inferior vena cava. (Ann Vasc Surg 1991 ;5:459-461). KEY WORDS: Intraoperative ultrasonography; ultrasound; inferior vena cava thrombosis; thrombosis.
The upper or proximal limit of inferior vena caval thrombosis is often difficult to delineate with accuracy. This limit, however, is of the utmost value as a guide to appropriate surgical treatment. Three investigative techniques are classically used to assess the upper limit of thrombus: cavograms, computed t o m o g r a p h y (CT), or magnetic resonance imaging (MRI). E a c h of these techniques, however, has its shortcomings and is difficult to obtain under emergency conditions. We have recently used intraoperative sonography of the inferior vena cava (IVC) in two patients, one with suprarenal, the other with an infrarenal thrombosis.
From the Clinique Chirurgicale and the Service de Radiologie Vasculaire, HOpital Cochin, Paris, France. Reprint requests: Yves Chapuis, MD, Clinique Chirurgical, HOpital Cochin, 27, rue du Faubourg Saint-Jacques, 75014 Paris, France.
CASE REPORTS
Case No. 1 A 54-year-old man was referred for right lower limb vein thrombosis eight weeks after surgical intervention for cecal perforation. Phlebograms showed an iliofemoral clot and heparin was initiated. Twenty-four hours later, pulmonary thromboembolism occurred. The left inferior pulmonary field was found on pulmonary arteriograms to be amputated. Cavograms were obtained during the same session and showed that the clot extended in the IVC to a point 3 cm above the renal veins (Fig. 1). Operation was through a right subcostal incision. Kocher's maneuver was performed to expose the IVC. Intraoperative sonography was performed with a Scannel 300 (CGR) using a 5 mHz " T " probe. The retrohepatic vena cava was investigated transhepatically. For investigation of the infrahepatic vena cava, saline was gently poured into the abdomen to create a fluid interface. The superior limit of the thrombus was identified at the level of the inferior margin of the caudate lobe. The lobe was retracted, four caudate veins were ligated allowing clamping of the IVC above the clot. The clot was then cleared to below the ostia of the renal veins through a cavotomy.
459
460
INTRAOPERATIVE ULTRASONOGRAPHY OF IVC THROMBOSIS
ANNALS OF VASCULAR SURGERY
Fig. 2. Intraoperative ultrasonography showing longitudinal view of caval thrombosis.
Fig. 1. Preoperative cavogram showing partial thrombosis of the suprarenal inferior vena cava.
Lastly, an Adams-de Weese device was placed infrarenally. The patient made an uneventful recovery. Heparin was continued six weeks postoperatively. Asymptomatic thrombosis of the infrarenal vena cava occurred. Renal function has remained normal and the patient was well at one year.
Case No. 2 A 26-year-old woman, para one, gravida one, experienced thoracic pain, hyperpyrexia, and restlessness 24 hours after a normal delivery. The diagnosis of pulmonary thromboembolism was confirmed on phlebocavograms and pulmonary arteriograms. Low grade hematuria was found, suggesting thrombosis of the renal veins. Thrombosis of the infrarenal IVC was noted on cavograms. The upper limit of the thrombus, however, was not visualized with accuracy. Considering the young age of the patient and the hemorrhagic risk of anticoagulant therapy in the immediate postpartum period, interruption
of the IVC with evaluation of the patency of the renal veins was decided. The IVC was approached through a right subcostal incision and Kocher's maneuver. Intraoperative sonography (Figs. 2,3) showed that the vena caval thrombus remained below the renal veins. An Adams-de Weese device was clipped on the infrarenal IVC. After an uneventful postoperative course, the patient is well at two years. DISCUSSION In most cases of thrombosis of the IVC, the proximal limit of the clot is flush with the renal veins and does not extend any higher because o f the high rate of flow at their level. Nevertheless, in 5% of cases, the tip of the clot can extend beyond this limit [1]. This increases the risk of pulmonary embolism as well as the risk of thrombosis of the renal veins. Vena caval filters can be placed by the jugular route just proximal to the renal veins. Although this will certainly contribute to prevent further pulmonary embolism [2], thrombosis of the renal veins still remains possible. Intracaval devices are rarely advocated in the young subject because of lack of adequate long-term results in this setting.
VOLUME 5 N o 5 - 1991
INTRAOPERATIVE U L T R A S O N O G R A P H Y OF lVC THROMBOSIS
Fig. 3. Intraoperative uitrasonography showing transversal view of caval thrombosis.
When the thrombosis extends to the suprarenal IVC, the usual therapeutic plan is to clear the suprarenal IVC and to place an A d a m s - d e Weese device below the renal veins. Patient status, however, has to be consistent with the magnitude of this procedure, as the operation m a y be hemorrhagic [3] with the need for autotransfusion. The principal difficulty resides in the correct delineation of the u p p e r limit of the clot. Preoperative c a v o g r a m s do not always allow determination of this limit with a c c u r a c y [4]. C o m p u t e d tomography with e n h a n c e m e n t can be contributive when vascular injection of contrast medium is made through the pedal veins. H o w e v e r , when thrombosis is recent, or when contrast medium injection is made through the upper limbs, visualization of the clot can be less than optimal. Moreover, laminar renal vein flow can be responsible for false images of filling defects [5]. N u c l e a r M R I is promising because both the t h r o m b u s and IVC can be visualized in a frontal plane. This investigative method is I
461
not always available, however, and in order to avoid possible interference, there should not be any ferromagnetic material in the field of application [6]. While sonography is most often inadequate when used externally, images obtained with the p r o b e in direct contact with the IVC are accurate. Flowing blood generates hypoechoic images while coagulated blood is responsible for strong hyperechoic areas which contrast well with the adjacent media. The retrohepatic v e n a c a v a can be visualized through the hepatic p a r e n c h y m a . The infrabepatic IVC is best visualized through a saline interface. The clot is visualized as a regular hyperechoic image whose extremity is either round or flameshaped, located within an hypoechoic area corresponding to flowing blood. The upper limit of clot can be determined and the patency of the renal veins documented. As the probe is never in direct contact with the IVC, the risk of clot mobilization is reduced with this method. When the clot extends behind the liver, the IVC may be freed by successive ligations of the caudate veins. The pericaval peritoneum is incised, the liver is retracted cephalad, and the accessory hepatic veins are exposed. The IVC can be clamped just distal, rather than above, the hepatic veins. This means that there will be less hemorrhage upon opening the vena cava because the hepatic veins are excluded. These two cases illustrate that intraoperative sonography allows the surgeon to determine the upper limit of clot in IVC thrombosis. The method is reliable, accurate, and without any risk. It m a y be adapted to local anatomic conditions. We advocate the routine use of intraoperative sonography when performing infrarenal IVC interruption, REFERENCES 1. PIQUET PH, TOURNIGAND P, JOSSO B, et al. Traitement chirurgical des thromboses ilio-caves: exigences et r6sultats. In: KIEFFER E (Ed). Chirurgie de la Veine Cave InfPrieure et de ses Branches. Paris: L'Expansion Scientifique Franqaise, 1985, pp 210-216. 2. RICCO JB, CROCHET D, SEBILLOTE P, el al. Le filtre endo-cave per-cutan6 LGM: r6sultats pr6coces d'une 6tude multicentrique. Ann Chir Vasc 1988;2:242-247. 3. BRANCHEREAU A, ELIAS A, BORDEAUX J, et al. Thromboses aigues ilio-caves: traitement m6dical ou chirurgical. In: KIEFFER E (Ed). Chirurgie de la Veine Cave Inf(rieure et de ses Branches. Paris: L'Expansion Scientifique Fran~aise, 1985, pp 19%209. 4. VUJIC [, STANLEY J, TYMINSKI LJ. Computed tomography of suspectedcaval thrombosissecondaryto proximalextension of phlebitis from the leg. Radiology 1981;140:437~-41. 5. BARNES PA, BERVARDINO ME, THOMAS JL. Flow phenomenon mimicking thrombus: a possible pitfall of the pedal infusion technique. J Camput Assist Tomogr 1982:6: 304-306. 6. HRICAK H. AMPARO E. FISHER MR, et al. Abdominal venous system: assessment using MR. Radiology 1985;156: 415-422. !1 Iii