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![HEPATIC STEATOSIS
• Imaging studies [US/CT/MRI] can detect the presence of hepatic
steatosis
• Limited in quantifying the degree of steatosis.
• Ryan et al. : could not accurately quantify the degree of hepatic
steatosis using imaging (US or contrast-enhanced CT or both).
Liver Transpl 2002;
• Iwasaki et al. suggested that quantification of steatosis may be
possible by calculating the liver to spleen ratio (L:S) on
unenhanced CT
• A L:S of ≤1.1 has a sensitivity of 0.83, specificity of 0.82 and accuracy
of 0.82 in detecting steatosis of ≥30%).
Transplantation 2004](https://image.slidesharecdn.com/preopdonorworkupinldlt-181222075907/85/PREOPERATIVE-DONOR-WORKUP-FOR-LDLT-13-320.jpg)
![• Modern CT [e.g., MeVis Liver Analzyler and LiverView, (Bremen, Germany)]
and MRI software produce 3 D liver models that enable
volume measurements (total liver and graft volumes)
permit virtual hepatectomy as part of pre-surgical planning.
• Relatively accurate in estimating actual graft volumes (AGV/AGW)
• Estimated errors: Mainly related to graft perfusion
• Schroeder et al. reported a mean inaccuracy rate for graft volume
prediction of 9 and 12% using CT and MRI, respectively, when compared
to actual graft weight (AGW).
• Salvalaggio et al. found a significant difference between MRI-derived
graft volumes and intraoperatively measured graft volumes.
• Lee et al. found a 9% AGW overestimate by MRI when compared to AGW.
• Sakamoto et al. found that CT inaccuracies ranged from 32%
underestimation to 21% overestimation of AGW by volume.
G. Low et al. Clinical Radiology, 2008](https://image.slidesharecdn.com/preopdonorworkupinldlt-181222075907/85/PREOPERATIVE-DONOR-WORKUP-FOR-LDLT-30-320.jpg)
![SEGMENT IV ARTERY
• Variant dominant supply to segment IV by the RHA (11%)
• Needs to be preserved for adequate regeneration in donor
• Significant for both right and left-lobe transplants.
• In right-lobe transplants, if inadvertedly transected – l/t medial
segment ischaemia of the remnant liver.
• Identification of this vessel alerts the surgeon to avoid this
complication by placing the clamp on the RHA distal to the take
off of the segment IV branch.
• Left lobe transplant :Double arterial anatomoses [LHA and
segment IV variant artery] may be necessary
• May be sacrificed if intra hepatic communication with seg II/III
artery present
Sahani D., et al. RadioGraphics 2004
Yamaoka Y.,et al. Transplantation 1994](https://image.slidesharecdn.com/preopdonorworkupinldlt-181222075907/85/PREOPERATIVE-DONOR-WORKUP-FOR-LDLT-49-320.jpg)
Uploaded byDr Amit Dangi
PREOPERATIVE DONOR WORKUP FOR LDLT
The document summarizes the key steps and considerations in evaluating potential living liver donors. The evaluation involves a multi-stage process including medical history, physical exam, imaging to assess liver volume and anatomy, and further tests as needed. Factors like obesity, steatosis, and variant anatomy require special consideration. The goals are to ensure the donor's safety, obtain an adequate graft for the recipient, and identify any contraindications to donation.
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PREOPERATIVE DONOR WORKUP FOR LDLT
- 1. PRE OPERATIVE WORKUP OF LIVING DONOR FOR LDLT PRESENTED BY: DR. AMIT DANGI MODERATOR: DR VIVEK GUPTA
- 2. LIVING DONOR TRANSPLANTATION •Important aspects which formed the basis of LDLT were : -- “Regenerative capacity” of liver -- Understanding of liver anatomy -- 8 segments : formed the basis of partial grafts • 3 types of allografts used : Rt. Hemiliver ( Seg V to VIII) Lt. Hemiliver ( Seg II to IV) Lt. Lateral segment (Seg II,III)
- 3. AIM OF DONOREVALUATION • No harm be done to donor • Recipient gets the best graft for optimal outcome • Anatomical factors that preclude a safe donation be identified and donors excluded
- 4. DONOR EVALUATION The comprehensivemedical evaluation includes: • History and physical evaluation • Blood analysis • Cardiology evaluation and clearance • Gynecological evaluation • Psychosocial evaluation • Imaging (CT/MRI/MRCP): Steatosis, anatomy (biliary, venous, portal, arterial), volume
- 5. KEY POINTS 1. Thedonor evaluation is performed in three/four staged phases to disqualify inappropriate candidates as early as possible in the process. 2. Approximately half the potential transplant recipients are unable to identify a suitable donor for evaluation. 3. Approximately half the individuals evaluated for living donation are found suitable. 4. The donor pool in many parts of the country is significantly limited by the high prevalence of obesity. (Liver Transpl 2003;9:S2-S7.)
- 6. STEP-WISE EVALUATION PROTOCOL FORPOTENTIAL LIVE LIVER DONORS FOLLOWED IN ILBS Pamecha et al. Hepatol Int 2016
- 7. STEP 1 • Age:18-55 years (No definite cut-off, some accept donors upto 65 years of age, <50 years at ILBS) • Medical history: : DM, hypertension, IHD, malignancy, PUD, mental illness. • Mild systemic disease, such as well-controlled mild hypertension or diet-controlled diabetes, is not necessarily a contraindication to donation. Robert Brown Gastroenterology, 2008 • Drug and allergy history., • Gynecological evaluation: Contraceptive practice for female of reproductive, Pregnancy test if sexually active. • Clinical psychological assessment. • Physical examination: : Weight, Height, BMI (>35 excluded, 30-35 caution), BP, heart, lung, and abdominal examination. • Cardiac evaluation (Echocardiography or stress echo) • Body size compatibility (donor and recipient are within approximately 30% body weight of each other.) • LIVER TRANSPLANTATION 13:509-515, 2007 • Totter et al. Liver Transpl 2003
- 8. LABS AND OTHERPREOPERATIVE WORK UP • CBC, INR, activated prothrombin time. • Biochemistry: LFT, GGT, amylase, RFT, random glucose. • Thyroid profile • Serology: HBsAg, HBsAb, HBcAb, antiHCV, HIV I/II. • Virology-CMV IgG, EBV-VCA IgG, toxoplasmosis (in pediatric cases) , • Urinalysis • Hematology: Blood type (Identical or compatible) and screen. • Tumor markers (CEA, CA19.9 if age >45 years) • CXR (To screen for latent tuberculosis , Identify parenchymal lung disease) • ECG • Echocardigraphy and stress echo in select cases • USG Abdomen
- 9. SPECIAL CONSIDERATIONS AND/ORISSUES IN DONOR EVALUATION : OBESITY • Obesity (BMI > 28 kg/m2) in potential donors is an increasingly common problem • BMI> 35 : exclude, BMI: 0-35: Caution • A recent study showed that 78% of potential donors with BMI > 28 kg/m2 had hepatic steatosis (>10%) on liver biopsy. • Most centres exclude donors who have greater than 10% steatosis on liver biopsy. • Ryan et al found that 73% of overweight (BMI > 25 kg/m2) donors had little or no hepatic fat and 9% of candidates with a BMI < 25 kg/m2 had 10% or greater steatosis. (poor correlation with BMI and hepatic steatosis. ) Liver Transpl 2002 • Higher surgical morbidity in obese patients. • Selected obese patients (BMI upto 35-40) may be considered for living liver donation after careful evaluation (Reports of BMI • Weight loss programmes • Overweight nonobese women may be more suitable for donation than similar-sized men. Trotter et al. Liver Transpl 2003;9:S2-S7.)
- 10. HEPATITIS B COREANTIBODY- POSITIVE DONOR • HBV surface antigen positive : Excluded from donation. • HBV core antibody and HBV surface antigen negative (No active disease) : Can donate • Presence of HBV core antibody indicates previous HBV infection, which can result in chronic liver damage. • Liver biopsy : Mandatory - Presence of hepatic fibrosis would preclude donor hepatectomy • Studies from Asia: Risk of hepatectomy in the HBcAb -positive donor is not greater than in other donors. • Risk of transmission of HBV from donor to recipient. (seen in upto 75% of cases with cadaveric transplantation) • HBV prophylaxis ( either hepatitis B immunoglobulin or lamivudine or both) to living donor liver transplant recipients of grafts from HBV core antibody-positive donors successfully prevents the acquisition of recipient HBV. de Villa VH, et al. Transplantation 2008 Hwang S, Moon DB, et al. Transplantation 2003 Chen YS, et al. Clin Transplant 2002 Uemoto S, et al. Transplantation 1998
- 11. STEP 2 :IMAGING • Estimation of steatosis : Liver attenuation index (LAI) on CT • Ductal anatomy • Volumetric analysis (right, left, & caudate lobe; and for pediatric recipients, left lateral segment). • Venous and portal anatomy: Maximum intensity projections of HV and PV on CECT • Arterial anatomy: 3-dimenional reconstruction of hepatic artery. • Incidental lesions
- 12. STEP 3 AND4 • Step 3 Liver biopsy if signs of fatty liver from CT. (Upto 10% fatty change is acceptable) Visceral angiogram if computed tomography angiographic features not informative. • Step 4 Informed consent of LDLT from donor and recipient. Minor consent from a relative of the potential donor with no direct interest from the recipient. LIVER TRANSPLANTATION 13:509-515, 2007
- 13. HEPATIC STEATOSIS • Imagingstudies [US/CT/MRI] can detect the presence of hepatic steatosis • Limited in quantifying the degree of steatosis. • Ryan et al. : could not accurately quantify the degree of hepatic steatosis using imaging (US or contrast-enhanced CT or both). Liver Transpl 2002; • Iwasaki et al. suggested that quantification of steatosis may be possible by calculating the liver to spleen ratio (L:S) on unenhanced CT • A L:S of ≤1.1 has a sensitivity of 0.83, specificity of 0.82 and accuracy of 0.82 in detecting steatosis of ≥30%). Transplantation 2004
- 14. • Raptopoulas etal. suggest that dual-energy CT maybe useful in quantifying steatosis. • In their study of 21 patients imaged at 80 and 140 kV, a significant decrease in liver density (reflected in HU measurements) is seen at 140 kV compared to 80 kV, in fatty livers when compared to normal livers. • Hepatic steatosis of ≤25, ≤50, and ≥75% is associated with a 6, 11, and 20 HU decrease, respectively. Raptopoulos V., et al. AJR Am J Roentgenol 1991
- 15. QUANTIFICATION OF STEATOSIS • Severemacrovesicular steatosis (> 60%) - >60% risk of primary graft non function • Moderate steatosis (30-60 %) – Decreased hepatocyte regeneration, increased graft non function, ischemic injury • Liver Biopsy- Gold standard but invasive. • Liver bx: Not routinely indicated, overweight donors or CT/MRI s/o steatosis • CT based grading system – Liver Attenuation Index (LAI) used: Most commonly used • MRI or MR spectroscopy can predict presence of significant steatosis (>15%) • 2 point Dixon method on dual echo chemical shift MRI: Sensitivity/Specificity >80% in detecting >5% steatosis. Rinella et al 2003 Hwang et al 2004 Kim et al.: Living Donor Liver Transplant 2018
- 16. LIVER ATTENUATION INDEX (LAI) •LAI = MHA – MSA • LAI- Liver Attenuation Index • MHA- Mean Hepatic Attenuation • MSA- Mean Splenic Attenuation • A mean of 10 readings of attenuation on unenhanced CT images of liver and spleen used • Predicts the degree of steatosis in the donor liver.
- 17. • LAI >5 HU : < 5% Steatosis : Proceed with further evaluation • LAI- 5 to – 10 HU – 6- 30 % Steatosis : Needs biopsy • LAI- < -10 HU - > 30% Steatosis : Not considered for donation • Macrovesicular steatosis upto 10 % accepted by most centers for LDLT. • Steatosis upto 50% have been used for LDLT. • Donors with mild to moderate steatosis to undergo liver biopsy to confirm the same. • Individuals with > 20 % steatosis on liver biopsy are advised on life style changes, weight reduction and dietary modification Pamecha et al 2016 Limanond et al 2004.
- 18. LIVER BIOPSY • Routine:Only some centres. • Selective use: Common practice • Concern regarding histological status of the liver: • Age > 45 years (ILBS) Significant history of alcohol intake, BMI > 28 kg/m2 (selected patients), Elevated serum ferritin level, Presence of steatosis on imaging studies HBV core antibody-positive donor. Genetic relationship to a person with autoimmune or genetic liver disease • Liver biopsy can determine the presence of any underlying histological liver damage and determine the presence and extent of hepatic steatosis. Tran T, et al. Gastroenterology 2008.
- 19. BILE DUCT ANATOMY • Normalpattern seen only in ~ 60 % • Anatomical information important to prevent post op complications • Pre-op evaluation essential to formulate surgical plan and prevent complications. Nakamura et al , 2002
- 20. VARIANT BILIARY ANATOMY Biliaryvariants in Left lobe Healey & Schroy, 1953
- 21. VARIANT BILIARY ANATOMY Doubleorifice : - Seen usually in Rt. Lobe grafts - Options for management - Single anastomosis with/ without ductoplasty - Double anastomosis - Less complications in latter - Stents can be used : Internal / External. Onishi et al, 2003
- 22. VARIANT BILIARY ANATOMY RPSDto LHD - ~ 15 % cases - May be injured during graft harvesting Trifurcation : - Does not preclude donor surgery but requires pre-op planning. - A plane ~ 2.5 cm from ligamentum venosum gives single LHD in ~ 90% cases Farias et al, 2013 Goldman et al , 2003
- 23. VARIANT BILIARY ANATOMY -Isolated biliary variants not contraindication for LDLT - Combined Biliary and portal venous anomalies can preclude liver donation. - Pre-op planning with MRCP or techniques like Intra-op Cholangiography help in decreasing complications ( ~ 1.9%) Itamoto T et al, 2006
- 24. EVALUATION OF BILIARY ANATOMY ERCP Invasive, technical challenging Procedure associated complications MDCT Cholangiography IV biliary contrast agents ( iodipamide meglumine (Cholografin) 2/3-D format (MPR/MIP/VR) Second order branches well delineated Me Vis Software with use of iv biliscopin (meglumine iotroxate) Uptake of CT cholangiography is slow never the less, partly because of the perceived risk of contrast-related reactions IOC Standard and most accurate Information available only on table MRI Standard peroperative evaluation of biliary tree Spatial resolution of MRCP is lower than CTCP, particularly non dilated ducts Excretory MRCP: mangafodipir trisodium and gadobenate dimeglumine
- 25. CT VS MRIFOR BILIARY ANATOMY • Yeh et al. found that CT cholangiography enabled significantly better biliary tract visualization of second- order bile ducts than conventional or mangafodipir trisodium-enhanced excretory MR cholangiography, either alone or in combination. Yeh B.M., et al. Radiology 2004
- 26. INTRA OPERATIVE CHOLANGIOGRAPHY • Cysticduct cannulated • Slow instillation of the dye • A second cholangiogram just before division of RHD
- 27. THE COUNTER CLOCKWISE ROTATION •Different body axis and hepatic axis • Reorientation of an oblique liver image to AP view. A. Before rotation B. After Counterclockwise rotation
- 28. SECOND CHOLANGIOGRAM A. INITIAL B.AFTER COUNTERCLOCKWISE ROTATION C. AFTER PARENCHYMAL TRANSECTION (MARKER AT PROPOSED CUT SIITE) D. AFTER LIVER DIVISION
- 29. LIVER VOLUME ASSESSMENT • Aim •Adequate graft volume to sustain metabolic function in recipient (Recipient outcome) • Graft size – to – body weight ratio (GRBW) – 0.8-1% • Sufficient estimated residual liver volume (ERLV) to ensure adequate reserve for donor (Donor safety) • ERLV > 30% • No consensus exists on the most clinically effective method.
- 30. • Modern CT[e.g., MeVis Liver Analzyler and LiverView, (Bremen, Germany)] and MRI software produce 3 D liver models that enable volume measurements (total liver and graft volumes) permit virtual hepatectomy as part of pre-surgical planning. • Relatively accurate in estimating actual graft volumes (AGV/AGW) • Estimated errors: Mainly related to graft perfusion • Schroeder et al. reported a mean inaccuracy rate for graft volume prediction of 9 and 12% using CT and MRI, respectively, when compared to actual graft weight (AGW). • Salvalaggio et al. found a significant difference between MRI-derived graft volumes and intraoperatively measured graft volumes. • Lee et al. found a 9% AGW overestimate by MRI when compared to AGW. • Sakamoto et al. found that CT inaccuracies ranged from 32% underestimation to 21% overestimation of AGW by volume. G. Low et al. Clinical Radiology, 2008
- 31. • Done on3 D work station with volumetric software. • Line drawn from IVC along MHV to the GB fossa • Manually mark the borders of the Rt and left lobes with software assisted interpolation in the intervening images 3D-volume rendered CT liver volumetry with (a) total liver volume, (b) right lobe volume and (c) left lobe volume.
- 33. PITFALLS • Estimated error– 10% • Weight vs volume • Volumetry measures the volume of each lobe. • Conversion factor of 1.19 ml/g needed b/w volume and wt. • Practically wt and volume used interchangibly. • Lemke et al. found a conversion factor of 0.75 for calculated graft volume and AGW of the non- perfused graft improved measurement accuracy Lehmke A., et al Rofo 2003; 175: pp. 1232-1238
- 34. LIVER VOLUME Three criteriasused : - Estimated Standard Liver Volume (SLV) - Graft to Recipient Body Weight Ratio (GRWR) : >0.8 - Remnant Liver Volume (RLV) : 30-40% - Body size compatibility - No not proceed with further evaluation with a GRWR < 0.6 or a FLR <30 %. Pamecha et al. 2016
- 35. LIVER VOLUME Standard LiverVolume : - Based on body surface area(BSA) - Estimated using Urata’s formula Urata K et al 1995 - BSA calculated using Mosteller’s formula Mosteller RD 1987 Pitfall : Non uniformity in calculation. Chandramohan et al. 2012 Marginal concordanace was found between the formula derived calculation and GV for right lobe donors, but error ratio is lower for radiologic estimates. Salvalaggio et al 2005
- 36. LIVER VOLUME Graft RecipientBody Weight Ratio (GRWR) : - Ideal is > 0.8. For pediatric patients it is taken as 1 – 3 %. - Need to consider recipient’s disease and degree of PHTN also. - Few reports of successful transplant in GRWR < 0.8 - GRWR < 0.8: Selected low MELD, minimal decompensation, good performance status in recipient. - Graft weight to standard liver volume of recipient should be about 30–40% (with 40–45% needed in recipients with portal hypertension. Kiuchi T., et al Transplantation 1999 Soejima Y., et al. Liver Transpl 2003 Kamel I.R., et al. AJR Am J Roentgenol 2001
- 37. Remnant Liver Volume: - In LDLT donor safety is essential aspect - Remnant liver volumes of 30–40% of the total liver volumes is sufficient for the donor to survive, provided the liver parenchyma is normal with no steatosis Lo C.M., et al. Am Surg 1997 • Minimum volume for safe post-op recovery in donor is 30%. Fan et al 2000 - Donors with remnant volume > 37% usually do not have morbidity. Taner et al. 2008 • Left lateral segment graft (20% donor volume) or left-lobe graft (40% donor volume) is sufficient for adult-to-child donation. • Right-lobe graft (60% donor volume) is usually required for adult-to- adult donation. G. Low et al. Clinical Radiology, 2008
- 38. HEPATIC VENOUS ANATOMY •Right, Middle and Left Hepatic vein draining into IVC. • Intersegmental course
- 39. IMPORTANT CONSIDERATIONS ARE: • Prevent congestion of the graft • To look for safe hemihepatectomy plane
- 40. DOMINANT MIDDLE HEPATIC VEIN •May preclude Right liver graft or MHV needs to be included in the graft. - 10 % population - Short RHV supplying only seg VII - Needs to be included in the graft. Busuttil 2002
- 41. ACCESSORY HEPATIC VEINS AccessoryHepatic Vein : - 10 – 15% - > 5 mm: Reanastomosis - < 5 mm can be sacrificed Opening of accessory vein > 4 cm from primary opening difficult to reconstruct. IRHV : 3 – 5% Most common variant Large accessory vein Requires reconstruction
- 42. ABERRANT SEG VIIIVEIN - Found in 9% population - Careful planning to prevent congestion • Need to reconstruct if MHV not included in the graft. Catalano et al , 2003 Kamel IR et al , 2004
- 43. MIDDLE HEPATIC VEINANATOMY . MHV drainage patterns : enables preoperative determination of hepatectomy plane. - Total MHV retrieval : The MHV taken with graft. - Subtotal MHV : drainage of seg IVb left with remnant. ‘Coring’ technique may be used - Subtotal MHV retrieval helps to use lower remnant liver volumes. Ravi Mohan et al 2010 AS Soin et al, JACS 2011
- 44. (Ann Surg 2003;238:275– 282)
- 45. DETERMINATION THE VOLUMEOF CONGESTED SEGMENTS IN RIGHT LOBE GRAFTS • Segments V and VIII are predominately drained by the MHV. • Right lobectomy without MHV inclusion leads to venous outflow congestion., and ultimately SFS syndrome. • CT/MRI techniques provide Segmental volume determination and appreciation of MHA branching anatomy, and Assessment of number and size of accessory hepatic veins present • In cases where imaging demonstrates significant congestion volumes, HV reconstruction or right lobectomy with MHV inclusion are options. • In cases where congestion volumes are minimal, a standard right lobectomy may suffice. Yonemura Yet al. Liver Transpl 2005 Park E.A., et al. J Comput Assist Tomogr 2007; Asakuma M., et al. . Am J Transplant 2007; Lee S.,et al. Transplantation 2001
- 46. HEPATIC ARTERIAL ANATOMY •Michel’s Classification of branching pattern • Type 1: Normal (75.7%) • Type 2: Replaced or accessory LHA from left gastric artery (9.7%) • Type 3: Replaced or accessory RHA from the SMA (10.6%) • Type 4: Replaced or accessory LHA plus replaced or accessory RHA (2.3%) • Type 5: CHA from SMA (1.5%) • Type 6: CHA from aorta (0.2%)
- 47. VARIANT ARTERIAL ANATOMY •Implications : - Extensive and careful dissection in case of variant anatomy. - Predisposes the transplant to ischaemic parenchyma - Requires microsurgical techniques - May require “Y” graft or interposition graft in case of two arterial orifices. - Small vessels may be ligated if backflow is good Mori et al. Transplantation 1992 Marcos et al. Transplantation 2003 Ikegami et al. Surgery 1996
- 48. NORMAL REPLACED LHAACCESSORY RHA A replaced right or left hepatic artery makes the donor operation easier.
- 49. SEGMENT IV ARTERY •Variant dominant supply to segment IV by the RHA (11%) • Needs to be preserved for adequate regeneration in donor • Significant for both right and left-lobe transplants. • In right-lobe transplants, if inadvertedly transected – l/t medial segment ischaemia of the remnant liver. • Identification of this vessel alerts the surgeon to avoid this complication by placing the clamp on the RHA distal to the take off of the segment IV branch. • Left lobe transplant :Double arterial anatomoses [LHA and segment IV variant artery] may be necessary • May be sacrificed if intra hepatic communication with seg II/III artery present Sahani D., et al. RadioGraphics 2004 Yamaoka Y.,et al. Transplantation 1994
- 50. VARIANT PORTAL ANATOMY •Common (20% of the population) but less frequent than those of the hepatic arteries, and biliary ducts. • Increased significance in era of LDLT • Critical role of pre-operative evaluation to formulate surgical plan.
- 51. TECHNICAL MODIFICATIONS INTHE RECONSTRUCTION OF DUAL PORTAL VEIN Methods of Reconstruction in a variant portal anatomy Nakamura et al. Transplantation 2002
- 52. • Type I• Type II
- 53. TYPE III PORTALVEIN • Significantly Lower ERLV • 31% have ERLV < 30% • If RAPV arises in the umbilical fissure, the course is intrahepatic and may be injured • Requires either double reconstruction or back table reconstruction
- 54. VARIANT PORTAL ANATOMY Implications: - Usually not a contraindication of LDLT - Requires pre-op surgical planning for favorable outcome - Type E considered as contraindication. - In the other variant where the RAPV drains into the LPV and the RPPV drains into the MPV, right-lobe donation would require two PV anastomoses, which makes the surgery longer and increases the risk for PVT. Ayad et al, 2008 Nakamura et al, 2002
- 55. DANGEROUS ANATOMIES • Absentright Portal Vein • Segment IV vein from RAPV • Absent LPV
- 56. PERTINENT VASCULAR ANDBILIARY VARIATION AND SURGICAL IMPLICATIONS Kim et al.: Living Donor Liver Transplant 2018
- 57. “ALL-IN-ONE” IMAGING PROTOCOLS •CT and MRI have been assessed for their suitability in providing “all-in-one” imaging. • Schroeder et al. : performed “all-in-one” imaging using triphasic dual contrast MDCT in 250 potential liver donors • The study found that biliary and vascular anatomy was displayed to at least the second intrahepatic branch in all but seven patients. • An et al. : Gadobenate dimeglumine enhanced MRI study : 86.6% accuracy for arterial anatomy, 100% accuracy for PV anatomy, and 100% accuracy for major HV with 88.2% accuracy for minor branches. • Goyen et al : Gadobenate dimeglumine-enhanced MRI study : 100% correlation with catheter angiography for arterial, portal venous and hepatic venous anatomy, and the biliary system was consistently demonstrated to the level of the first hepatic side branch when correlated with the intra-operative findings (obtained in 16 patients). Schroeder T., et al. Liver Transpl 2005 An S.K., et al. AJR Am J Roentgenol 2006 Goyen M., et al. Liver Transpl 2002; Yu F.C., et al. Transplantation 2001;
- 58. COMPARISON OF THEPERFORMANCE BETWEEN CT AND MRI “ALL-IN-ONE” • Schroeder: both are effective in evaluating donor anatomy as a single diagnostic step. • CT was the best option because of its superior ability in delineating biliary anatomy. • This finding was supported by Yeh et al. who found that CT cholangiography enables significantly better biliary tract visualization than conventional or excretory contrast- enhanced MR cholangiography – either alone or in combination. • Concerns regarding “all-in-one” CT Significantly larger radiation exposure (15–20 mSv) Potentially nephrotoxic contrast agents, accompanied by a risk of adverse reactions. Schroeder T., et al. Liver Transpl 2005; Yeh B.M., et al. Radiology 2004;
- 59. DETAILS OF DONOR-RELATED REASONS FOR NOT PROCEEDING TO DONATION DURING STEP WISE EVALUATION IN LIVING DONOR LIVER TRANSPLANTATION Pamecha et al. Hepatol Int 2016
- 60. SUMMARY • Anatomical variationare a rule than a exception • Imaging helps identify unfit donors • Prevents intra operative surprises and complications
Editor's Notes
- #3 To offset the imbalance between demand and supply of cadaveric organs, LDLT came into practice.. Live donor liver transplantation was also adopted for pediatric and high-urgency situations provided that the donor was suitable and the recipient considered salvageable.
- #4 According to LDLT data, the donor mortality rate is between 0.5% and 1% Nevertheless, the inevitable donor morbidity and mortality remain the major drawbacks of LDLT, as the donors undergo major surgery for the recipients and not for themselves.. Unanimously, the transplant community agreed upon the notion of safety first for the donor.
- #5 Blood analysis to exclude viral and autoimmune liver diseases diabetes, hyperlipidemia, hypercoagulable states.
- #7 The criteria for initiation of donor evaluation at ILBS are : voluntary related or emotionally attached donors with no known co-morbidity, aged between 18 and 50 years, body mass index (BMI) \28 kg/m2 and blood group compatible.
- #8 New York State mandates an upper age limit of 60 years. Donors under 18 years are generally felt unacceptable. Phase 1 is designed to deter- mine that the potential donor meets all the appropriate inclusion criteria for donation: appropriate blood type, age, body size, and relationship to the recipient. No other immunologic matching other than blood type is required of the potential donor. A detailed medical and drug history is taken to identify any medical problem that may increase morbidity or mortality from donor hepatectomy. There is a consensus in the transplant community that donors are healthy subjects. History of diabetes, hypertension, ischemic heart disease, malignancy within the last 5 years, and active mental disorders preclude the candidacy of donation. History of peptic ulcer disease mandates an upper endoscopy. Mild hypertension and well controlled DM is not a C/I. Donation is also precluded in the presence of peptic ulcer. Allergic history is clarified. Female potential donors of reproductive age who are sexually active undergo a pregnancy test. The use of oral contraceptive pills indicates perioperative deep vein thrombosis prophylaxis by subcutaneous heparin in addition to physical means. A BMI> 30 does not automatically preclude the potential donor, but it manifests a cautionary sign for fatty liver and underlying medical problems related to obesity. Blood group compatibility is verified. All living donor candidates underwent a psychosocial evaluation to determine whether there was coercion and they truly understood the risks of the procedure by a team that included psychiatrists, psychologists, and psychiatric nurses
- #9 . Hepatitis B surface antigen positivity and hepatitis C positivity preclude donation. The presence of antibody to hepatitis B core antigen represents previous exposure to hepatitis B virus but is not an absolute contraindication for donation. However, lifelong hepatitis B prophylaxis for the recipient by nucleoside analogue reverse transcriptase inhibitor is mandatory if the recipient is hepatic B surface antigen negative.
- #10 However, there are no data regarding outcomes after LDLT with the use of stea-totic grafts. As a result, most centers exclude obese donors from evaluation. one report showed a poor correlation with BMI and hepatic steatosis. Ryan et al12 found that 73% of overweight (BMI 25 kg/m2) donors had little or no hepatic fat and 9% of candidates with a BMI of 25 kg/m2 or less had 10% or greater steatosis.
- #11 The consideration of HBV core antibody- positive donors is particularly important in regions of the world where HBV infection is endemic and a large number of LDLT procedures are performed. For exam- ple, in many parts of Asia, LDLT is the only option for liver transplantation, and more than 50% of the (blood donor) population may be HBV core antibody posi- tive.21 The presence of hepatic fibrosis would preclude donor hepatectomy on the basis of graft suitability, as well as donor safety.
- #12 For ALDLT, the right liver is often used unless the donor is substantially heavier than the recipient. The right liver of the donor to the estimated standard liver volume less than 35% is associated with increased recipient mortality,14 and thus donor candidacy will be cancelled. A contraindication exists if the right anterior portal vein arises from the left portal vein distal to the umbilical fissure. Presence of substantial inferior hepatic vein(s) allows anticipation during operation. Attention to the presence of segment 4b hepatic vein or segment 3 hepatic vein draining into the middle hepatic vein calls for a more caudal division of the middle hepatic vein to preserve adequate drain- age of segment 4 of the remnant left liver.13 Hepatic artery anatomy is best shown by the 3-dimensional reconstructions. The replaced right hepatic artery pro- vides a long hepatic artery segment in the graft, but the aberrant position is also predisposed to premature sev- ering in the donor procedure. The location of the seg- ment 4 hepatic artery is also determined.
- #13 Step 3 Suggestion of fatty change of the liver as detected by CT mandates liver biopsy, which is to be done only after affirmation of suitability of the donor otherwise. A fatty change of up to 10% by histopathology is acceptable. Step 4 Informed consent including donor and recipient mor- bidity and mortality as spelled out will be obtained from the potential donor. A minor consent is obtained from a donor relative who has no direct benefit from the recip- ient’s operation. Human leukocyte antigen typing and cross-match are then performed.
- #14 Ryan et al., in a study of 100 prospective right-lobe liver donors, could not accurately quantify the degree of hepatic steatosis using imaging (US or contrast-enhanced CT or both).
- #16 As a consequence of the demand and supply imbalance for transplants, suboptimal grafts may sometimes be used with some centres prepared to accept mildly steatotic grafts (≤30% concentration). 15 16 Transplants with steatotic grafts of up to 50% have also been used, but are associated with a greater risk of ischaemic–reperfusion injury. 17
- #18 After a trial of opti- mization, LAI and biopsy are repeated; if they are in the normal range, then the potential donor is subjected to further evaluation, otherwise he/she is rejected. In ILBS study, 10 (7.4 %) donors ini- tially had [10 % macrovesicular steatosis or steatohepati- tis that resolved after dedicated efforts of strict diet and exercise. They could successfully donate after a repeat biopsy showed resolution.
- #19 The role of liver biopsy in the donor evaluation process varies greatly from center to center. Protocol liver biopsies in an otherwise suitable donor with normal LFT results may discover minimal abnormalities (mini- mal portal inflammation, <10% steatosis). Other indications for liver biopsy include potential donors with abnormal liver function tests, steatosis on imaging, individuals with BMI[28 who are on a weight loss program aimed towards donation, age [45 years, genetic relationship to a person with autoim- mune or genetic liver disease and hepatitis B virus core positive serology. Individuals with [20 % steatosis on liver biopsy are advised on life style changes, weight reduction and dietary modification
- #20 Anomalous biliary tract anatomy (present in 40% of the population poses significant technical challenges for LDLT surgery. Postoperative biliary complications (incidence of 15–40% in recipients, 56 57 4–13% in donors 58 59 ) are the bane of LDLT largely due to the technical difficulties of performing biliary reconstruction on small calibre bile ducts and due to the propensity to severe postoperative bile leakage if even minor intrahepatic branches that cross the dissection line are unknowingly transected. 60 These challenges are intensified in cases of variant anatomy where multiple duct openings maybe required and anatomy is generally more complex
- #30 Estimation of graft volume is critical in LDLT to optimize safety and recipient outcome Accurate size matching of the donor and recipient is essential to ensure that functional hepatic mass is available to both sustain metabolic demands and to permit volume regeneration. Inadequate graft size leads to “small-for-size” syndrome, a clinical entity that encompasses graft dysfunction, liver failure, and even death. 22 Presence of portal hypertension in the recipient may also contribute to small-for-size syndrome as a result of portal over perfusion of the graf
- #31 Despite good correlation between estimated and actual graft volume, allowances must be made for a margin of error The main cause of these discrepancies is thought to be related to graft perfusion as imaging volumetry measures the volume of the perfused liver whereas weight measurements of the actual graft are performed when it is devoid of blood content.
- #33 The radiologist encircles the right hepatic lobe using the middle hepatic vein as the left border and utilizing computer software calculates the hepatic volume and weight.
- #35 Various formulae to determine acceptable graft and remnant liver volumes have been developed and are recognized independent predictors of survival after transplantation. Graft to recipient body weight ratio should be ≥0.8% and preferably ≥1%. 24 Graft weight to standard liver volume of recipient should be about 30–40% (with 40–45% needed in recipients with portal hypertension). 11 25 26 Remnant liver volumes of 30–40% of the total liver volumes is sufficient for the donor to survive, provided the liver parenchyma is normal with no steatosis. 11 Body size compatibility between the donor and recipient is an important preliminary consideration in the donor evaluation. At our center, we require that the donor and recipient are within approximately 30% body weight of each other. In most cases in which the recipient’s body weight is 30% or greater of the donor’s body weight, the donor will be unable to yield a large enough graft for the recipient
- #37 Graft to recipient body weight ratio should be ≥0.8% and preferably ≥1%. Only in carefully selected situations (low model for end-stage liver disease score, minimal decompensation, good performance status in recipient), are GRWR \0.8 or FLR \35 % (entire middle hepatic vein in remnant ensuring no congestion) accepted for further evaluation. The authors do not proceed with further evaluation with a GRWR \0.6 or a FLR \30 %.
- #44 For right-lobe transplants, knowledge of MHV drainage pattern enables preoperative determination of the hepatectomy plane. Traditionally, this surgical plane courses 1 cm to the right of the MHV. Presence of early bifurcation of the MHV to the right may result in small right-lobe grafts requiring either modification of the surgical plane or rejection of the potential donor as an eligible candidate for transplantation. Presence of large branching veins draining into the MHV from right-lobe segments may require re-anastomosis of these vessels in the recipient. 50 51 If drainage of the anterior segment is required, taking the MHV instead of reconstruction of its lesser tributaries would be a more simple and straightforward approach and the risk of thrombosis is reduced, if not eliminated. On the other hand, if the functional mass of the graft was adequate without the MHV, some degree of congestion may be tolerated in the early postoper- ative period until the graft would have regenerated.
- #45 Algorithm for determining the extent of donor hepatectomy in right lobe living donor liver transplantation, with or without the middle hepatic vein (MHV). DRBW, donor- recipient body weight ratio; RLRSLV, right lobe-to-recipient standard liver volume estimate; V5, draining vein of segment V; V8, draining vein of segment VIII; RHV, right hepatic vein Based on certain preoperative criteria, a right lobe graft can be taken with or without the middle hepatic vein with equally successful outcomes in both the donors and recipients. The decision, therefore, of the extent of right lobe donor hepatectomy should be tailored to the particular conditions of each case.
- #46 These imaging applications can also determine the volume of congested segments in right lobe grafts. Right lobectomy without MHV inclusion results in disruption of the MHV branches to these segments leading to venous outflow congestion. These congested segments show suboptimal liver function and so the amount of fully functioning graft tissue is reduced, which may lead to small-for-size syndrome
- #47 Occur in 20%-45% of the total population. May receive blood supply from the SMA, LGA, aorta, or other visceral branches. Aberrant hepatic artery : branch that does not arise from its usual source. May be “Accessory” or “Replaced” CT or MR angiography.
- #51 FIGURE 1. Anatomical types of right portal vein branching defined by branch(es) to the anterior segment. Type C repre- sents extraparenchymal and type D intraparenchymal branching of the anterior branch. Incidence of each type was: 111 (92.5%) (A); 3 (2.5%) (B); 3 (2.5%) (C); 2 (1.7%) (D); and 1 (0.8%) (E). Right (R) and left (L) branches; Anterior (A) and posterior (P) branches; P4, P5, and P8, portal venous branches to segments 4, 5, and 8, respectively; F, falciform ligamen
- #52 Type B portal vein was anastomosed in end-to-end fashion to the recipient portal trunk (Fig. 2a). Dual anastomosis to the bifurcation of the recipient portal vein was used in two type B cases and two type C cases (Fig. 2b). In an extremely rare case of type E, graft P8 was finally sacrificed. A venous graft was interposed for the reconstruction of P5 (Fig. 2c). The interposed venous graft was anastomosed with the recipient portal trunk in end-to-side fashion in two type D cases (Fig. 2d). The anterior branch diverged into P5 and P8 immediately after its origin deep in parenchyma in one type D case. The relatively smaller P5 was finally sacrificed after the reconstruction of the posterior branch and P8. To overcome size discrepancy, the recipient portal trunk was divided longitudinally and two vessels were reconstructed in one case of type C (Fig. 2e).
- #58 Donor evaluation is frequently a multi-technique imaging process and time consuming.and puts substantial demands on radiology resources. To simplify and shorten this diagnostic pathway and make it a more acceptable experience for donors, some centres have explored the possibility of performing donor evaluation as a single comprehensive imaging study. CT and MRI have been assessed for their suitability in providing “all-in-one” imaging – providing simultaneous assessment of hepatic parenchymal morphology and detailed analysis of vascular and biliary anatomy. Some variants were missed or misinterpreted on imaging (four biliary, five arterial, one portal venous, and six hepatic venous) but on retrospective assessment, these could be detected in all but one biliary and one hepatic venous case.
- #60 Common donor-related reasons were: donor reluctance (23.5 %), neg- ative liver attenuation index (16.2 %), anatomic variations (10.3 %), inadequate remnant liver volume (9.8 %), unac- ceptable liver biopsy (8.8 %), and inadequate graft volume (5.4 %). A majority of donors (82.8 %) were turned down early in the (steps 1 and 2) evaluation process. Recipient death was the most common recipient-related reason [n = 51 (43.6 %)] for not proceeding to donation It is important to know themost frequent reasons of donor elimination is so important for transplantation centers to gain time. If the centers know their most common causes of donor candidate elimination, they can concentrate on these reasons and may prevent unnecessary tests. The main causes of donor candidate elimination are different in different centers. According to Sharma et al, 52.7% donors were disqualified and the most frequent donor candidate elimination causes were donor reluctance, hepatic steatosis, and assisted donor withdrawal [16] . Blood type incapability and anatomic details were the common causes of donor elimination (76% of donor candidates were excluded) in a different study