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Abstract

  1. Top of page
  2. Abstract
  3. SMALL-FOR-SIZE SYNDROME (SFSS) IN LIVING DONOR LIVER TRANSPLANTATION (LDLT)
  4. REDUCING BILIARY COMPLICATIONS
  5. RECONSTITUTION OF THE MHV OUTFLOW IN RIGHT LOBE GRAFTS
  6. SAFE HEPATIC ARTERY AND PORTAL VEIN RECONSTRUCTION
  7. OTHER ADAPTATIONS FOR IMPROVING RECIPIENT OUTCOMES
  8. SUMMARY
  9. REFERENCES

Key Points

1. Over the course of the past 2 decades, living donor liver transplantation (LDLT) has become increasingly successful because many of the technical issues plaguing it have been resolved.

2. Although donor safety remains a concern, most challenges related to the recipient's surgery are now better understood, and they appear surmountable.

3. The following concepts need to be addressed for optimal recipient outcomes to be achieved:

a. Reduction of the risk of small-for-size syndrome in LDLT (ie, the management of 4 factors: the recipient status, the portal pressure and inflow, the venous outflow, and the graft-to-recipient weight ratio/graft quality).

b. Reduction of the risk of surgical complications (biliary complications, reconstitution of the middle hepatic vein outflow in the right lobe graft, and safe hepatic artery and portal vein reconstruction).

c. Other adaptations for improving recipient outcomes (adaptations related to LDLT and adaptations common to deceased donor liver transplantation and LDLT). Liver Transpl, 2012. © 2012 AASLD.


SMALL-FOR-SIZE SYNDROME (SFSS) IN LIVING DONOR LIVER TRANSPLANTATION (LDLT)

  1. Top of page
  2. Abstract
  3. SMALL-FOR-SIZE SYNDROME (SFSS) IN LIVING DONOR LIVER TRANSPLANTATION (LDLT)
  4. REDUCING BILIARY COMPLICATIONS
  5. RECONSTITUTION OF THE MHV OUTFLOW IN RIGHT LOBE GRAFTS
  6. SAFE HEPATIC ARTERY AND PORTAL VEIN RECONSTRUCTION
  7. OTHER ADAPTATIONS FOR IMPROVING RECIPIENT OUTCOMES
  8. SUMMARY
  9. REFERENCES

SFSS is characterized by the presence of hyperbilirubinemia, coagulopathy, ascites, and (in advanced stages) sepsis and encephalopathy occurring in the first week after transplantation. It is especially common when the graft-to-recipient weight ratio (GRWR) is <0.8.1

SFSS has a multifactorial genesis: a combination of donor factors (graft volume/quality and hepatic artery buffer response) and recipient factors (portal hyperperfusion, spleen-to-liver volume ratio, venous outflow, and stage of liver disease) leads to allograft dysfunction after partial liver transplantation.2 The following measures should be taken to prevent SFSS.

Improving the Quality and Quantity of Liver Grafts

We do not accept livers from donors with abnormal liver function or from donors with steatosis > 20% in cases of right lobe donation or > 30% in cases of left lobe donation.3 Our minimum acceptable limit for GRWR is 0.8. In select cases with compensated liver disease, we accept lower GRWR grafts with a portal pressure–reducing measure.4, 5

Pretransplant Recipient Status

We do not use donor livers of borderline quality or volume in sick recipients.

Good Venous Outflow

We ensure complete venous drainage [including drainage of the middle hepatic vein (MHV) territory] in all right lobe grafts. Our policy for MHV outflow reconstruction is as follows. We retain the MHV in a majority (approximately 75%) of right lobe grafts (Fig. 1). As we recently reported,3 various MHV lengths are retrieved, and we make sure that the distal MHV with any significant segment IVa veins is preserved in the donor. The MHV can usually be retained with the right lobe because there is sufficient segment IVb drainage into the left hepatic vein in 93% of cases, and there is adequate segment IVa drainage into the left hepatic vein in 80% of cases. When the venous anatomy suggests otherwise, there is >10% steatosis, or the remnant is <32%, the MHV is retained with the donor. In that case, separate segment V and VIII veins are isolated and preserved during transection, and they are later extended via vascular conduits and drained directly into the inferior vena cava.

thumbnail image

Figure 1. Image of a right lobe graft being retrieved with a subtotal length of the MHV (blue sling) and with the segment V and VIII hepatic veins draining into it.

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Prevention of Portal Hyperperfusion and Hepatic Artery Buffer Response

In patients with small-for-size grafts, portal hyperperfusion and increased portal pressure may be observed in the immediate posttransplant period after partial grafting, and they can lead to sinusoidal congestion and hemorrhagic necrosis of perisinusoidal hepatocytes within minutes.6 An elevated portal pressure produces a reciprocal reduction in arterial perfusion via the hepatic artery buffer response, which further augments the hepatocyte damage.7

We routinely measure the portal pressure and the portal flow during the recipient's surgery. With low-GRWR grafts (<0.8), we aim for a portal pressure ≤18 mm Hg by using splenic artery ligation and/or a hemiportocaval shunt with a flow of one-half to two-thirds of the graft's portal flow. The ideal portal flow into the graft should be 100 to 300 mL/minute/100 g of liver tissue. These measures also prevent a hepatic artery buffer response.

Spleen-to-Liver Volume Ratio

Some have recommended prophylactic splenic artery ligation in patients whose spleen-to-liver volume ratio is greater than 0.5 (ie, patients with big spleens).8 However, we believe that the spleen-to-liver volume ratio is just a surrogate marker of the degree of portal hypertension rather than an independent predictor of SFSS. Paying attention to the portal hemodynamics (as discussed previously) is more directly beneficial.

REDUCING BILIARY COMPLICATIONS

  1. Top of page
  2. Abstract
  3. SMALL-FOR-SIZE SYNDROME (SFSS) IN LIVING DONOR LIVER TRANSPLANTATION (LDLT)
  4. REDUCING BILIARY COMPLICATIONS
  5. RECONSTITUTION OF THE MHV OUTFLOW IN RIGHT LOBE GRAFTS
  6. SAFE HEPATIC ARTERY AND PORTAL VEIN RECONSTRUCTION
  7. OTHER ADAPTATIONS FOR IMPROVING RECIPIENT OUTCOMES
  8. SUMMARY
  9. REFERENCES

Biliary complications are more likely in LDLT patients (especially right lobe recipients) than deceased donor liver transplantation (DDLT) recipients because of the high incidence of multiple ducts, which are often thin-walled and small in caliber. This makes them less likely to hold sutures and more at risk for twisting and other technical errors. Skeletonizing them can also lead to ischemia. In order to minimize the incidence of biliary complications, we have evolved a standard protocol using the complete hilar plate and Glissonian sheath (HPGS) approach.9 This entails the isolation and encirclement of the complete HPGS envelope around the graft hepatic duct (HD) or HDs posteriorly down to the caudate lobe during the donor hepatectomy (Fig. 2A). Because the peribiliary arterial plexus lies within the hilar plate, which itself is thick-walled, the technique mitigates all the potential problems of biliary anastomoses in partial grafts. It allows a thick cover of sheath around the graft HD or HDs (Fig. 2B), which provides a sturdy enough wall to hold sutures, ensures a good ductal arterial blood supply, prevents the retraction of small HDs, and keeps them in their natural lie with respect to one another; this facilitates twist-free anastomoses. The other important components of our technique are as follows. For the donor operation:

  • 1
    Initially, cholecystectomy and cholangiography are performed.
  • 2
    The graft hepatic artery and portal vein are bared to leave the Glissonian sheath and hilar plate tissue intact around the HDs.
  • 3
    The HD confluence is defined by the lowering of the hilar plate before the transection.
  • 4
    Just before the parenchymal transection is completed, the ipsilateral HPGS complex with the HD is exposed and encircled.
  • 5
    The graft HD (covered by its HPGS complex after complete parenchymal transection) is transected.
  • 6
    The HD stump is closed with fine polydioxanone sutures. A leak test using methylene blue and cholangiography is performed.
  • 7
    At the bench, no ductoplasty is performed because it would distort the duct openings; caudate duct openings are oversewn.
thumbnail image

Figure 2. (A) Image of encircled right HDs (yellow sling) along with the covering HPGS complex in a right lobe retrieval. (B) Image of a right lobe graft on the bench showing the right anterior and posterior HDs covered by a thick envelope of hilar plate.

Download figure to PowerPoint

For the recipient operation:

  • 1
    All periductal tissue is preserved; the high hilar dissection and the HD division are performed above its confluence.
  • 2
    A tension-free duct-to-duct anastomosis (mostly) or a Roux-to-duct anastomosis is created with interrupted fine polydioxanone sutures.
  • 3
    A single anastomosis is used if there is a single HD or there are 2 HDs up to 3 mm apart. Multiple anastomoses are used if HDs are more than 3 mm apart.
  • 4
    No stents are used for a duct-to-duct anastomosis; a transjejunal stent is used for a Roux-to-duct anastomosis.
  • 5
    The recipient's cystic duct is used for the anastomosis if it is widely patent and well vascularized.
  • 6
    A methylene blue leak test is performed via the cystic duct whenever this is possible. Fibrin glue is used for the cut surface and over biliary anastomoses.

SAFE HEPATIC ARTERY AND PORTAL VEIN RECONSTRUCTION

  1. Top of page
  2. Abstract
  3. SMALL-FOR-SIZE SYNDROME (SFSS) IN LIVING DONOR LIVER TRANSPLANTATION (LDLT)
  4. REDUCING BILIARY COMPLICATIONS
  5. RECONSTITUTION OF THE MHV OUTFLOW IN RIGHT LOBE GRAFTS
  6. SAFE HEPATIC ARTERY AND PORTAL VEIN RECONSTRUCTION
  7. OTHER ADAPTATIONS FOR IMPROVING RECIPIENT OUTCOMES
  8. SUMMARY
  9. REFERENCES

Hepatic Artery Reconstruction in LDLT

The interruption of the hepatic artery inflow to a liver graft results in ischemic damage to the parenchyma (especially in the first 2-4 weeks) and to the biliary tract (invariably) and thus results in graft loss. Unlike the hepatic artery in a deceased donor whole graft, the hepatic artery in a living donor partial graft is thin-walled, small-caliber, often short, and sometimes multiple. Hence, the reported hepatic artery thrombosis rates are higher for LDLT patients versus DDLT patients (5%-26%),10 and this necessitates extra caution and expertise for the reconstruction.

The salient points of our arterial dissection and reconstruction protocol include the following. For the donor:

  • 1
    Dissect the graft hepatic artery by clearing the adjacent tissue without handling or touching the artery directly.
  • 2
    Spare any segment IV artery in cases of right hepatic artery dissection.
  • 3
    Avoid traction injury.
  • 4
    At the time of graft removal, divide the artery just distal to an atraumatic vascular clamp applied proximally to avoid intimal damage.

For the recipient:

  • 1
    Dissect the right, middle, and left hepatic arteries individually high into the hepatic hilum by clearing the adjacent tissue without handling or touching the arteries directly.
  • 2
    Avoid traction injury.
  • 3
    Divide the artery after applying an arterial clamp proximally and surgical clips distally to avoid intimal damage.

For reconstruction:

  • 1
    Use 3× surgical loupes.
  • 2
    Freshen both ends.
  • 3
    Use 7-0 or 8-0 interrupted Prolene sutures.
  • 4
    Avoid caliber mismatch > 50%.
  • 5
    Ensure the correct lie.
  • 6
    In cases with difficult/multiple/very short and small arteries, sometimes use microvascular reconstruction (18/1060 or 1.7%).

Intraoperative Doppler ultrasound is used to ensure a good arterial trace and signal. If it is necessary, the anastomosis can be revised.

In pediatric recipients and in difficult small-caliber anastomoses, anticoagulation in the form of systemic heparin is administered after the reconstruction, and it is continued as low-molecular-weight heparin initially and later as warfarin for 3 months. In others, aspirin alone in antiplatelet doses is given for 3 months. With this protocol, our hepatic artery thrombosis rate has been 1.7% for the last 1060 consecutive LDLT procedures.

Portal Vein Reconstruction in LDLT

A portal vein obstruction can result in graft dysfunction or failure early on or can cause ascites, thrombocytopenia, and portal hypertensive complications later. Although reconstruction is usually straightforward, major technical issues arise in small recipients and in recipients with pretransplant portal vein thrombosis (PVT).

Attention must be paid to the following points to achieve a safe portal vein anastomosis. In cases of pretransplant PVT:

  • 1
    A good preoperative computed tomography venogram and PVT classification are essential for planning the reconstruction.
  • 2
    Extra blood loss should be anticipated in cases of major PVT without significant spontaneous portocaval shunts.
  • 3
    Intraoperative thrombendvenectomy or the exclusion of a chronic, well-intimized thrombus is usually possible for obtaining good portal inflow. Occasionally, spontaneous portosystemic shunts may need to be ligated (depending on the portal pressures and flows on Doppler ultrasound imaging) to establish adequate hepatopetal portal flow.

For portal vein reconstruction:

  • 1
    The portal vein is dissected bare in the recipient and the donor.
  • 2
    An anastomosis is created with continuous 6-0 Prolene sutures; this leaves a growth factor and avoids redundancy of the veins.
  • 3
    Intraoperatively, a postperfusion portal pressure ≤ 18 mm Hg is desirable, especially for grafts with a GRWR < 0.8. When the pressure is high, splenic artery ligation, a hemiportocaval shunt, or both are used with one-half to two-thirds of the hepatic portal flow.
  • 4
    In small children, an interrupted anastomosis with 7-0 Prolene sutures is created with as short and wide a portal vein stump as possible on the recipient's side.

Our current PVT rate is 1.7% in 1060 cases. The reported rates elsewhere are 1% to 12.5%.10

OTHER ADAPTATIONS FOR IMPROVING RECIPIENT OUTCOMES

  1. Top of page
  2. Abstract
  3. SMALL-FOR-SIZE SYNDROME (SFSS) IN LIVING DONOR LIVER TRANSPLANTATION (LDLT)
  4. REDUCING BILIARY COMPLICATIONS
  5. RECONSTITUTION OF THE MHV OUTFLOW IN RIGHT LOBE GRAFTS
  6. SAFE HEPATIC ARTERY AND PORTAL VEIN RECONSTRUCTION
  7. OTHER ADAPTATIONS FOR IMPROVING RECIPIENT OUTCOMES
  8. SUMMARY
  9. REFERENCES

Adaptations Specific to LDLT

Surface blood and bile leaks in the graft and the remnant are avoided during the donor's parenchymal transection through the clean division of most identifiable biliovascular pedicles between ligaclips or ligatures (rather than diathermy division). After the transection, we recheck both surfaces for hemostasis by raising the central venous pressure to 7 to 10 mm Hg, and we recheck for biliostasis with cholangiography and a methylene blue injection into the donor's bile duct. Finally, fibrin glue is sprayed onto both surfaces.

The duration of the recipient's hepatectomy and the blood loss can be considerably reduced through the use of the porta-first dissection technique and the intermittent or permanent clamping of the inflow at the time of the separation of the liver from the anterior surface of the inferior vena cava.

Adaptations Common to DDLT and LDLT

Our anesthesiologists preemptively replace blood products and even hypercorrect clotting in difficult cases (approximately 10%), such as patients with a history of hepatobiliary surgery, major PVT, or recurrent spontaneous bacterial peritonitis.

Other measures that positively affect recipient outcomes include careful attention to ambulation, nutrition, and renal and pulmonary function before the operation and optimization of perioperative infection controls.

With the described techniques, our current operative mortality rate for recipients is down to 6% (for the last 500 LDLT procedures).

SUMMARY

  1. Top of page
  2. Abstract
  3. SMALL-FOR-SIZE SYNDROME (SFSS) IN LIVING DONOR LIVER TRANSPLANTATION (LDLT)
  4. REDUCING BILIARY COMPLICATIONS
  5. RECONSTITUTION OF THE MHV OUTFLOW IN RIGHT LOBE GRAFTS
  6. SAFE HEPATIC ARTERY AND PORTAL VEIN RECONSTRUCTION
  7. OTHER ADAPTATIONS FOR IMPROVING RECIPIENT OUTCOMES
  8. SUMMARY
  9. REFERENCES

Although LDLT has been honed into an established and highly successful alternative to DDLT (for which donors are in short supply), it is technically demanding and poses its own challenges. SFSS can be prevented if an adequately sized graft of good quality is used, good venous outflow is ensured, and portal hyperperfusion is avoided. Biliary, arterial, and portal vein reconstruction can be made safer with the described techniques. With the evolution of various technical refinements, it is possible to achieve an operative mortality rate of approximately 5% for this complex group of patients.

REFERENCES

  1. Top of page
  2. Abstract
  3. SMALL-FOR-SIZE SYNDROME (SFSS) IN LIVING DONOR LIVER TRANSPLANTATION (LDLT)
  4. REDUCING BILIARY COMPLICATIONS
  5. RECONSTITUTION OF THE MHV OUTFLOW IN RIGHT LOBE GRAFTS
  6. SAFE HEPATIC ARTERY AND PORTAL VEIN RECONSTRUCTION
  7. OTHER ADAPTATIONS FOR IMPROVING RECIPIENT OUTCOMES
  8. SUMMARY
  9. REFERENCES
  • 1
    Dahm F, Georgiev P, Clavien PA. Small-for-size syndrome after partial liver transplantation: definition, mechanisms of disease and clinical implications. Am J Transplant 2005; 5: 26052610.
  • 2
    Gruttadauria S, Pagano D, Luca A, Gridelli B. Small-for-size syndrome in adult-to-adult living-related liver transplantation. World J Gastroenterol 2010; 16: 50115015.
  • 3
    Soin AS, Mohanka R, Singla P, Piplani T, Menon B, Kakodkar R, et al. Segment IV preserving middle hepatic vein retrieval in right lobe living donor liver transplantation. J Am Coll Surg 2011; 213: e5e16.
  • 4
    Ogura Y, Hori T, El Moghazy WM, Yoshizawa A, Oike F, Mori A, et al. Portal pressure <15 mm Hg is a key for successful adult living donor liver transplantation utilizing smaller grafts than before. Liver Transpl 2010; 16: 718728.
  • 5
    Troisi R, Ricciardi S, Smeets P, Petrovic M, Van Maele G, Colle I, et al. Effects of hemi-portocaval shunts for inflow modulation on the outcome of small-for-size grafts in living donor liver transplantation. Am J Transplant 2005; 5: 13971404.
  • 6
    Demetris AJ, Kelly DM, Eghtesad B, Fontes P, Wallis Marsh J, Tom K, et al. Pathophysiologic observations and histopathologic recognition of the portal hyperperfusion or small-for-size syndrome. Am J Surg Pathol 2006; 30: 986993.
  • 7
    Marcos A, Olzinski AT, Ham JM, Fisher RA, Posner MP. The interrelationship between portal and arterial blood flow after adult to adult living donor liver transplantation. Transplantation 2000; 70: 16971703.
  • 8
    Cheng YF, Huang TL, Chen TY, Concejero A, Tsang LL, Wang CC, et al. Liver graft-to-recipient spleen size ratio as a novel predictor of portal hyperperfusion syndrome in living donor liver transplantation. Am J Transplant 2006; 6: 29942999.
  • 9
    Soin AS, Kumaran V, Rastogi AN, Mohanka R, Mehta N, Saigal S, et al. Evolution of a reliable biliary reconstructive technique in 400 consecutive living donor liver transplants. J Am Coll Surg 2010; 211: 2432.
  • 10
    Akun E, Yaprak O, Killi R, Balci NC, Tokat Y, Yuzer Y. Vascular complications in hepatic transplantation: single-center experience in 14 years. Transplant Proc 2012; 44: 13681372.