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Splenorenal shunt closure after liver transplantation: intraoperative Doppler assessment of portal hemodynamics
Splenorenal Shunt Closure After Liver Transplantation: Intraoperative Doppler Assessment of Portal Hemodynamics Robert S. Shapiro,* C.V.R. Varma,† Myron E. Schwartz,† and Charles M. Miller†
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anagement of prior distal splenorenal shunt (DSRS) in patients undergoing orthotopic liver transplantation (OLT) is a complex issue. If not ligated, these shunts can draw portal flow away from the allograft and thus predispose the patient to complications after OLT.1 Intraoperative color Doppler sonography, by measuring flow velocity, can be used to quantitate changes in portal blood flow. We describe the use of intraoperative Doppler sonography to assess the hemodynamics of interrupting a DSRS after OLT.
Case Report A 61-year-old woman underwent OLT for end-stage liver disease secondary to autoimmune hepatitis. The patient had undergone a DSRS 8 years earlier. Pretransplant color Doppler sonogram showed thrombosis of the portal vein. At transplantation, portal vein thrombosis was confirmed, and donor iliac vein was used to construct a transmesocolic jump graft from the recipient superior mesenteric vein to the donor portal vein. Large collaterals were noted. The DSRS was left intact. Color Doppler sonography performed on postoperative day 1 showed the hepatic vessels to be patent but with bidirectional flow in the portal vein. Because of this finding, the patient was returned to the operating room. At surgery, it was discovered that a fresh thrombus had subsequently formed in the portal vein. A thrombectomy was performed. To assess the effects of closing the DSRS, the splenorenal anastomosis was dissected out, and the splenic vein was clamped just proximal to the anastomosis. Doppler assessment of the portal vein was performed with and without occluding the shunt. When the shunt was occluded, portal vein flow velocity increased to 162 cm/sec from a value of 36 cm/sec with the shunt open (Fig. 1). The DSRS was permanently ligated. Postoperative Doppler evaluation showed preservation of flow in the portal vein with a velocity of 156 cm/sec. The subsequent postoperative course was complicated by hepatic artery thrombosis, which resulted in retransplantation. Postoperatively, there was no recurrence of portal hypertension or varices. The patient died 6 months later from complications related to biliary strictures and sepsis.
Discussion A prior surgical portosystemic shunt can complicate OLT. In the past, preexisting shunts were considered an absolute or relative contraindication to OLT.2 The development of new reconstructive techniques now permits OLT in patients with previously placed shunts.2-4 There are two categories of surgical portosystemic shunts: nonselective and selective. Nonselective shunts decompress the entire splanchnic bed.5 Examples include portacaval, mesocaval, and central splenorenal shunts. Nonselective shunts must be interrupted at the time of OLT to assure adequate portal flow to the transplanted liver.2 Selective shunts divert only a portion of the portal blood. The DSRS or Warren shunt is an example. It decompresses gastroesophageal varices while maintaining hepatopetal flow to the liver through the superior mesenteric vein for a variable time after the procedure.5 Controversy exists regarding the need to interrupt a DSRS at the time of OLT.2,5,6 Over time, a DSRS becomes less selective as collaterals form between the nondecompressed mesenteric venous system and the decompressed splenic system.2,5,7 After OLT, these collaterals offer an alternative outflow, potentially decreasing portal flow to the liver and predisposing to portal thrombosis.8 Although DSRS is designed to maintain portal perfusion, portal thrombosis is not an uncommon sequela, with an incidence of about 10%9,10; in such cases, the development of mesenteric-tosplenic collaterals would be enhanced. In our case, competitive outflow through the
From the Departments of *Radiology and †Surgery, Mount Sinai School of Medicine, City University of New York, New York, NY. Address reprint requests to Robert S. Shapiro, MD, Department of Radiology, Box 1234, Mount Sinai Medical Center, One Gustave L. Levy Pl, New York, NY 10029-6574. Copyright r 1997 by the American Association for the Study of Liver Diseases 1074-3022/97/0306-0015$3.00/0
Liver Transplantation and Surgery, Vol 3, No 6 (November), 1997: pp 641-642
641
642
Shapiro et al
Figure 1. Intraoperative assessment of portal hemodynamics. The spectral tracing on the left shows that portal vein velocity is 162 cm/s (arrowhead) with shunt occluded (1 CLAMP). The tracing on the right shows that portal vein velocity is 36 cm/s (open arrow) with shunt open (2 CLAMP).
unligated DSRS resulted in decreased portal flow and subsequent thrombosis of the portal vein graft. The magnitude of the ‘‘steal’’ was shown graphically by intraoperative Doppler assessment of portal flow. When the DSRS was occluded, portal flow increased dramatically (Fig. 1). After permanent closure of the shunt, portal flow was maintained. Intraoperative Doppler assessment of portal flow has several advantages compared with alternative methods for evaluating patients with previously placed shunts. Woodle has advocated performing pretransplant mesenteric angiography to determine the extent of collateralization.2 Angiography is invasive, however, and does not permit assessment of the physiological effect of interrupting the shunt. Other investigators advocate routine shunt ligation with or without splenectomy. Adjunctive splenectomy is not desirable during OLT because it further compromises the immune status of patients who will require long-term immunosuppressive therapy. Splenectomy has been advised because of concern that occlusion of the splenic vein without splenectomy may result in splenic congestion and left-sided portal hypertension with gastroesophageal varices. As theorized by Woodle, interruption of a DSRS (without splenectomy) in patients with large portosystemic collaterals should allow effective decompression of the spleen through the collaterals and thus increase portal flow through the collaterals.2 Similarly, patients in whom Doppler assessment shows increased portal flow on shunt occlusion are unlikely to experience recurrent varices because the splenic outflow will be
provided by the same collaterals that resulted in the ‘‘steal’’ phenomenon. In summary, intraoperative Doppler sonography was used to assess portal hemodynamics after OLT in a patient with a previously placed DSRS. A significant increase in flow velocity on shunt occlusion provided direct evidence of competitive outflow through the shunt, indicating both the need for and the safety of shunt ligation. We suggest that intraoperative Doppler may be used to select patients who would benefit from ligation of their DSRS rather than their routine dismantling. Because intraoperative Doppler sonography is not available in all institutions, analogous information might be obtained with a Doppler flow meter. Although preexisting collaterals should provide adequate decompression of the spleen, larger studies are needed to determine if complications of left-sided portal hypertension occur in these patients.
References 1. Durham JD, LaBerge JM, Altman S, Kam I, Everson GT, Gordon RL, et al. Portal vein thrombolysis and closure following liver transplantation. Journal of Vascular and Interventional Radiology 1994;5:611-615. 2. Woodle ES. Portal vein thrombolysis and closure following liver transplantation—Invited commentary. Journal of Vascular and Interventional Radiology 1994;5:617618. 3. Kirsch JP, Howard TK, Klintmalm GB, Husberg BS, Goldstein RM. Problematic vascular reconstruction in liver transplantation. Part II. Portovenous conduits. Surgery 1990;107:544-548. 4. Lerut J, Tzakis AG, Bron K, Gordon RD, Iwatsuki S, Esquival CO, et al. Complications of venous reconstruction in human orthotopic liver transplantation. Ann Surg 1987;205:404-414. 5. Brems JJ, Hiatt JR, Klein AS, Millis JM, Collonna JO, Quinones-Baldrich WJ, et al. Effect of a prior portosystemic shunt on subsequent liver transplantation. Ann Surg 1989;209:51-56. 6. Esquivel CO, Klintman G, Iwatsuki S, Makowa L, Gordon RD, Tzakis A, et al. Liver transplantation in patients with patent splenorenal shunts. Surgery 1987;101:430432. 7. Maillard JN, Flamant YM, Hay JM, Chandler JG. Selectivity of the distal splenorenal shunt. Surgery 1979;86: 663-671. 8. Darcy MD. Portal vein thrombolysis and closure following liver transplantation—Invited commentary. Journal of Vascular and Interventional Radiology 1994;5:616617. 9. Rikkers LF. Is the distal splenorenal shunt better? Hepatology 1988;8:1705-1707. 10. Langer B, Taylor BR, Greig PD. Selective or total shunts for variceal bleeding. Am J Surg 1990;160:75-79.
M
anagement of prior distal splenorenal shunt (DSRS) in patients undergoing orthotopic liver transplantation (OLT) is a complex issue. If not ligated, these shunts can draw portal flow away from the allograft and thus predispose the patient to complications after OLT.1 Intraoperative color Doppler sonography, by measuring flow velocity, can be used to quantitate changes in portal blood flow. We describe the use of intraoperative Doppler sonography to assess the hemodynamics of interrupting a DSRS after OLT.
Case Report A 61-year-old woman underwent OLT for end-stage liver disease secondary to autoimmune hepatitis. The patient had undergone a DSRS 8 years earlier. Pretransplant color Doppler sonogram showed thrombosis of the portal vein. At transplantation, portal vein thrombosis was confirmed, and donor iliac vein was used to construct a transmesocolic jump graft from the recipient superior mesenteric vein to the donor portal vein. Large collaterals were noted. The DSRS was left intact. Color Doppler sonography performed on postoperative day 1 showed the hepatic vessels to be patent but with bidirectional flow in the portal vein. Because of this finding, the patient was returned to the operating room. At surgery, it was discovered that a fresh thrombus had subsequently formed in the portal vein. A thrombectomy was performed. To assess the effects of closing the DSRS, the splenorenal anastomosis was dissected out, and the splenic vein was clamped just proximal to the anastomosis. Doppler assessment of the portal vein was performed with and without occluding the shunt. When the shunt was occluded, portal vein flow velocity increased to 162 cm/sec from a value of 36 cm/sec with the shunt open (Fig. 1). The DSRS was permanently ligated. Postoperative Doppler evaluation showed preservation of flow in the portal vein with a velocity of 156 cm/sec. The subsequent postoperative course was complicated by hepatic artery thrombosis, which resulted in retransplantation. Postoperatively, there was no recurrence of portal hypertension or varices. The patient died 6 months later from complications related to biliary strictures and sepsis.
Discussion A prior surgical portosystemic shunt can complicate OLT. In the past, preexisting shunts were considered an absolute or relative contraindication to OLT.2 The development of new reconstructive techniques now permits OLT in patients with previously placed shunts.2-4 There are two categories of surgical portosystemic shunts: nonselective and selective. Nonselective shunts decompress the entire splanchnic bed.5 Examples include portacaval, mesocaval, and central splenorenal shunts. Nonselective shunts must be interrupted at the time of OLT to assure adequate portal flow to the transplanted liver.2 Selective shunts divert only a portion of the portal blood. The DSRS or Warren shunt is an example. It decompresses gastroesophageal varices while maintaining hepatopetal flow to the liver through the superior mesenteric vein for a variable time after the procedure.5 Controversy exists regarding the need to interrupt a DSRS at the time of OLT.2,5,6 Over time, a DSRS becomes less selective as collaterals form between the nondecompressed mesenteric venous system and the decompressed splenic system.2,5,7 After OLT, these collaterals offer an alternative outflow, potentially decreasing portal flow to the liver and predisposing to portal thrombosis.8 Although DSRS is designed to maintain portal perfusion, portal thrombosis is not an uncommon sequela, with an incidence of about 10%9,10; in such cases, the development of mesenteric-tosplenic collaterals would be enhanced. In our case, competitive outflow through the
From the Departments of *Radiology and †Surgery, Mount Sinai School of Medicine, City University of New York, New York, NY. Address reprint requests to Robert S. Shapiro, MD, Department of Radiology, Box 1234, Mount Sinai Medical Center, One Gustave L. Levy Pl, New York, NY 10029-6574. Copyright r 1997 by the American Association for the Study of Liver Diseases 1074-3022/97/0306-0015$3.00/0
Liver Transplantation and Surgery, Vol 3, No 6 (November), 1997: pp 641-642
641
642
Shapiro et al
Figure 1. Intraoperative assessment of portal hemodynamics. The spectral tracing on the left shows that portal vein velocity is 162 cm/s (arrowhead) with shunt occluded (1 CLAMP). The tracing on the right shows that portal vein velocity is 36 cm/s (open arrow) with shunt open (2 CLAMP).
unligated DSRS resulted in decreased portal flow and subsequent thrombosis of the portal vein graft. The magnitude of the ‘‘steal’’ was shown graphically by intraoperative Doppler assessment of portal flow. When the DSRS was occluded, portal flow increased dramatically (Fig. 1). After permanent closure of the shunt, portal flow was maintained. Intraoperative Doppler assessment of portal flow has several advantages compared with alternative methods for evaluating patients with previously placed shunts. Woodle has advocated performing pretransplant mesenteric angiography to determine the extent of collateralization.2 Angiography is invasive, however, and does not permit assessment of the physiological effect of interrupting the shunt. Other investigators advocate routine shunt ligation with or without splenectomy. Adjunctive splenectomy is not desirable during OLT because it further compromises the immune status of patients who will require long-term immunosuppressive therapy. Splenectomy has been advised because of concern that occlusion of the splenic vein without splenectomy may result in splenic congestion and left-sided portal hypertension with gastroesophageal varices. As theorized by Woodle, interruption of a DSRS (without splenectomy) in patients with large portosystemic collaterals should allow effective decompression of the spleen through the collaterals and thus increase portal flow through the collaterals.2 Similarly, patients in whom Doppler assessment shows increased portal flow on shunt occlusion are unlikely to experience recurrent varices because the splenic outflow will be
provided by the same collaterals that resulted in the ‘‘steal’’ phenomenon. In summary, intraoperative Doppler sonography was used to assess portal hemodynamics after OLT in a patient with a previously placed DSRS. A significant increase in flow velocity on shunt occlusion provided direct evidence of competitive outflow through the shunt, indicating both the need for and the safety of shunt ligation. We suggest that intraoperative Doppler may be used to select patients who would benefit from ligation of their DSRS rather than their routine dismantling. Because intraoperative Doppler sonography is not available in all institutions, analogous information might be obtained with a Doppler flow meter. Although preexisting collaterals should provide adequate decompression of the spleen, larger studies are needed to determine if complications of left-sided portal hypertension occur in these patients.
References 1. Durham JD, LaBerge JM, Altman S, Kam I, Everson GT, Gordon RL, et al. Portal vein thrombolysis and closure following liver transplantation. Journal of Vascular and Interventional Radiology 1994;5:611-615. 2. Woodle ES. Portal vein thrombolysis and closure following liver transplantation—Invited commentary. Journal of Vascular and Interventional Radiology 1994;5:617618. 3. Kirsch JP, Howard TK, Klintmalm GB, Husberg BS, Goldstein RM. Problematic vascular reconstruction in liver transplantation. Part II. Portovenous conduits. Surgery 1990;107:544-548. 4. Lerut J, Tzakis AG, Bron K, Gordon RD, Iwatsuki S, Esquival CO, et al. Complications of venous reconstruction in human orthotopic liver transplantation. Ann Surg 1987;205:404-414. 5. Brems JJ, Hiatt JR, Klein AS, Millis JM, Collonna JO, Quinones-Baldrich WJ, et al. Effect of a prior portosystemic shunt on subsequent liver transplantation. Ann Surg 1989;209:51-56. 6. Esquivel CO, Klintman G, Iwatsuki S, Makowa L, Gordon RD, Tzakis A, et al. Liver transplantation in patients with patent splenorenal shunts. Surgery 1987;101:430432. 7. Maillard JN, Flamant YM, Hay JM, Chandler JG. Selectivity of the distal splenorenal shunt. Surgery 1979;86: 663-671. 8. Darcy MD. Portal vein thrombolysis and closure following liver transplantation—Invited commentary. Journal of Vascular and Interventional Radiology 1994;5:616617. 9. Rikkers LF. Is the distal splenorenal shunt better? Hepatology 1988;8:1705-1707. 10. Langer B, Taylor BR, Greig PD. Selective or total shunts for variceal bleeding. Am J Surg 1990;160:75-79.