Changes in splenic volume during liver regeneration

Eight weeks of dry dynamic breath-hold training results in larger spleen volume but does not increase haemoglobin concentration

Purpose: It has previously been reported that repeated exposure to hypoxia increases spleen size and haemoglobin (HGB) level and recent reports on the effect apnoea has on spleen size and haematological parameters are contradictory. Therefore, this study aims to evaluate the effect apnoea training has on spleen size and haematological parameters.

Methods: The breath-holding (BH) group was comprised of 12 local student-athletes with no BH exercise experience who performed BH jogging and BH jumping rope dynamic apnoea protocols, five times weekly for 8 weeks. The BH event duration was progressively increased as the apnoea tolerance of the athletes improved (20 to 35 s). The same training task was performed by the control group (n = 10) without BH. Spleen sizes were measured with an ultrasound system and a complete blood cell analysis was performed on the median cubital venous blood.

Results: Spleen volume in the BH group increased from 109 ± 13 ml to 136 ± 13 ml (p < 0.001), and bulky platelets decreased from 70.50 ± 5.83 to 65.17 ± 5.87 (p = 0.034), but no changes were recorded for erythrocytes (p = 0.914), HGB (p = 0.637), PLTs (p = 0.346) and WBC (p = 0.532). No changes were recorded for the control group regarding spleen size or haematological parameters.

Conclusion: Eight weeks of dry dynamic apnoea training increased spleen size and decreased the number of circulating bulky platelets in the athletes who were assessed in this study. However, the baseline RBC counts and HGB levels of the athletes were not altered by the training programme.

Durability of partial splenic artery embolization on platelet counts for cancer patients with hypersplenism-related thrombocytopenia

PURPOSE

Partial splenic artery embolization (PSAE) has shown promise in increasing platelet counts in cancer patients with hypersplenism-related thrombocytopenia. The purpose of this study was to identify response predictors and to longitudinally evaluate PSAE efficacy and durability in a large cohort of cancer patients with hypersplenism-related thrombocytopenia.

METHODS

A single-institution, IRB-approved, HIPAA-compliant retrospective review of all PSAEs for thrombocytopenia between 2012 and 2015 was performed. Patients were classified as complete responders (CR, no platelet value < 100 × 10⁹/L following PSAE), partial responders (PR, initial increase in platelets but subsequent decrease in platelets < 100 × 10⁹/L), and non-responders (NR, platelets never > 100 × 10⁹/L following PSAE).

RESULTS

Of the 98 patients included in the study, 58 had CR (59%), 28 had PR (29%), and 12 patients had NR (12%). The percent splenic tissue embolized was significantly greater in the CR group compared to the PR group (P = 0.001). The percent volume of splenic tissue embolized was linearly correlated with the magnitude of platelet increase without a minimum threshold. At least one line of chemotherapy was successfully restarted in 97% of patients, and 41% of patients did not experience recurrence of thrombocytopenia for the duration of their survival. The major complication rate was 8%, with readmission following initial hospitalization for persistent "post-embolization syndrome" symptoms the most common.

CONCLUSIONS

In cancer patients with hypersplenism-related thrombocytopenia, PSAE is a safe intervention that effects a durable elevation in platelet counts across a range of malignancies and following the re-initiation of chemotherapy.

Long-term impact and clinical significance of living donor liver transplantation with respect to donor liver restoration and spleen size: A prospective study

This study aimed to evaluate postoperative long-term liver restoration and splenic enlargement and their clinical significance in living donor liver transplantation. One hundred and sixteen donors who had donated livers more than 5 years previously accepted the invitation to participate in this study. The liver restoration rate and the splenic enlargement rate were calculated as the rate with respect to the original volume. The mean liver restoration rate was 0.99 ± 0.12 and older age was associated with a higher incidence for liver restoration rate <0.95 (P = .005), whereas type of donor operation was not. The donors with liver restoration rate <0.95 showed lower serum albumin levels than those with liver restoration rate ≥0.95. The mean splenic enlargement rate was 1.10 ± 0.16. Right lobe donors demonstrated higher splenic enlargement rate (1.14 ± 0.18) than left lobe/lateral segment donors (1.06 ± 0.13). In the donors with splenic enlargement rate ≥1.10, platelet count was not fully restored to the preoperative level. In conclusion, older age increases the risk for incomplete postoperative liver restoration, which may be associated with a decrease in albumin more than 5 years after donation. Right lobe donation poses a risk of splenic enlargement, which is associated with incomplete restoration of platelet count.

Correlation of postoperative splenic volume increase with prognosis of hepatocellular carcinoma after curative hepatectomy

Background

Previous studies have reported a close connection between the spleen and hepatic tumours. We investigated the prognostic value of postoperative splenic volume increase (PSVI) in patients with hepatocellular carcinoma after curative hepatectomy.

Methods

This was a retrospective study of adult patients with hepatocellular carcinoma who underwent hepatectomy between January 2007 and May 2013. We categorized patients into 2 groups according to the cut-off value of the receiver operating characteristic curve: group A (PSVI < 19.0%) and group B (PSVI ≥ 19.0%). We compared the clinicopathological data, overall survival and disease-free survival between the 2 groups. We performed univariate and multivariate analyses to identify factors associated with disease-free and overall survival.

Results

There were 275 patients in group A and 196 patients in group B. The 1-, 3- and 5-year overall survival rates were 98.9%, 74.9% and 63.6%, respectively, for patients in group A, and 97.4%, 65.3% and 49.8%, respectively, for patients in group B (p = 0.004). The corresponding disease-free survival rates were 69.5%, 48.0% and 40.3%, and 58.1%, 36.5%, and 29.8% (p = 0.01). On multivariate analysis, PSVI was an independent predictor of overall (p = 0.01) and disease-free (p = 0.03) survival.

Conclusion

Postoperative splenic volume increase correlates with poor prognosis of patients with hepatocellular carcinoma after curative hepatectomy.

Early postoperative hypoalbuminaemia is associated with pleural effusion after donor hepatectomy: A propensity score analysis of 2316 donors

Pleural effusion and hypoalbuminaemia frequently occur after hepatectomy. Despite the emphasis on the safety of donors, little is known about the impact of postoperative albumin level on pleural effusion in liver donors. We retrospectively assessed 2316 consecutive liver donors from 2004 to 2014. The analysis of donors from 2004 to 2012 showed that postoperative pleural effusion occurred in 47.4% (970/2046), and serum albumin levels decreased until postoperative day 2 (POD2) and increased thereafter. In multivariable analysis, the lowest albumin level within POD2 (POD2ALB) was inversely associated with pleural effusion (OR 0.28, 95% CI 0.20-0.38; P < 0.001). POD2ALB ≤3.0 g/dL, the cutoff value at the 75th percentile, was associated with increased incidence of pleural effusion after propensity score (PS) matching (431 pairs; OR 1.69, 95% CI 1.30-2.21; P < 0.001). When we further analysed data from 2010 to 2014, intraoperative albumin infusion was associated with higher POD2ALB (P < 0.001) and lower incidence of pleural effusion (P = 0.024), compared with synthetic colloid infusion after PS matching (193 pairs). In conclusion, our data showed that POD2ALB is inversely associated with pleural effusion, and that intraoperative albumin infusion is associated with a lower incidence of pleural effusion when compared to synthetic colloid infusion in liver donors.

Chemotherapy-induced splenic volume increase is independently associated with major complications after hepatic resection for metastatic colorectal cancer

BACKGROUND

In patients with colorectal cancer liver metastases (CRCLM), chemotherapy-induced hepatic injury is associated with increased splenic volume, thrombocytopenia, and decreased long-term survival. The current study investigates the relationship between change in splenic volume after preoperative chemotherapy and development of postoperative complications.

STUDY DESIGN

The study group consisted of 80 patients who underwent resection of CRCLM; half received neoadjuvant chemotherapy for 6 months before resection (n = 40) and the other half did not (n = 40). The study group was compared with two control groups: a normal group composed of patients undergoing cholecystectomy for benign disease (n = 40) and a group of untreated, nonmetastatic colorectal cancer (CRC) patients (n = 40). Splenic volume was measured by CT/MRI volumetry. In the study group, the nontumoral liver was graded for steatosis and sinusoidal injury; operative and outcomes characteristics were also analyzed.

RESULTS

Before chemotherapy, CRCLM patients had normalized spleen volumes of 3.2 ± 1.1 mL/kg, significantly higher than normal (2.5 ± 0.8 mL/kg; p < 0.001) and nonmetastatic CRC (2.6 ± 1.3 mL/kg; p < 0.05) patients, with higher splenic volume after 6 months of chemotherapy (4.2 ± 1.7 mL/kg; p < 0.01). After chemotherapy, splenic volume increase was associated with any perioperative complication (p < 0.01) and major complications (p < 0.05). Patients with ≥39% splenic volume increase (maximal chi-square test) were significantly more likely to have major complications (p < 0.01). Spleen volume changes were not correlated with change in platelet count (R(2) = 0.03; p = 0.301).

CONCLUSIONS

In patients with CRCLM, the presence of liver metastases and chemotherapy are associated with higher splenic volume. Percent splenic volume increase after 6 months of chemotherapy can aid preoperative risk stratification, as it was an independent predictor of major postoperative complications.

Mechanisms of splenic hypertrophy following hepatic resection

BACKGROUND

Following hepatic resection, liver regeneration has been associated with concurrent splenic hypertrophy. The mechanisms of this phenomenon are unknown, may be multiple and include: splanchnic sequestration caused by a reduction in the hepatic mass; hepatic growth factors that may indirectly act on the spleen, and the redistribution of the total reticuloendothelial system.

METHODS

Seventy-five patients (40 males; median age: 60 years) who underwent minor (16%) or major (84%) hepatectomy between September 2004 and October 2009 were included. Prospective measurements of liver and spleen volumes were obtained preoperatively and postoperatively 1 month after hepatectomy using computed tomography (CT). The future remnant liver volume (RLV) was calculated on preoperative CT and the extent of resection was expressed as the RLV divided by total liver volume (TLV). Liver and spleen hypertrophy were expressed according to the absolute gain or relative increase in the initial volumes (%).The presence of fibrosis >F1, associated extrahepatic resection (except minor resections), and previous hepatectomy (major or minor) within 3 months represented exclusion criteria.

RESULTS

Mean ± standard deviation (SD) liver volume at 1 month was higher than RLV (1187 ± 286 cm(3) versus 764 ± 421 cm(3) ; P < 0.001). Mean ± SD splenic volume increased from 252 ± 100 cm(3) preoperatively to 300 ± 111 cm(3) at 1 month (P < 0.001). Liver and splenic hypertrophy were significant after major hepatectomies (+100% and +26%, respectively; P < 0.001), but not after minor hepatectomies. Liver hypertrophy was inversely correlated to RLV/TLV (r = -0.687, P < 0.001). Splenic hypertrophy was not correlated to RLV/TLV. Liver and splenic hypertrophy were linearly correlated (r = 0.495, P < 0.001). Neoadjuvant chemotherapy (n = 37), preoperative portal vein embolization (n = 10) and postoperative complications (overall: n = 25; major: n = 10; infectious: n = 6) had no impact on hepatic or splenic hypertrophy.

CONCLUSIONS

Splenic hypertrophy occurred after major hepatectomy, but was not correlated to the extent of resection, by contrast with liver hypertrophy. Nevertheless, there was a linear correlation between splenic and liver hypertrophy. This correlation suggests the hypothesis of a splenic action of hepatic growth factors or a redistribution of the total reticuloendothelial system rather than an effect of reduction of the portal bed or hepatic outflow.

Effect of donor right hepatectomy on splenic volume and platelet count for living donor liver transplantation

BACKGROUND

Donor hepatectomy for living donor liver transplantation accompanies physio-morphological changes of the liver and spleen. Therefore, the long-term consequences of these organs should be characterized to ensure donor's safety.

METHODS

A total of 382 right liver harvests for liver transplantation were performed from October 2000 to February 2011. Clinical parameters across donor operations were compared, and the associations were investigated.

RESULTS

The remaining liver grew continually, reaching 81.5 ± 11.2% of the entire liver until 6 months after donation. The spleen grew to 143.1 ± 28.8% of the pre-donation value within 1 week after surgery, and thereafter, its size decreased gradually to 130.6 ± 25.1% at 6 months. At 6 months post-donation, 48.1% (114/237) of donors showed an increase of ≥30% in splenic volume, and 15.9% (50/315) of donors exhibited a decrease of ≥30% in platelet count. However, patients with splenic enlargement and/or decrease in platelet count at 6 months post-donation were not different in liver function, liver regeneration, or overall complications.

CONCLUSIONS

Although splenic enlargement and/or decrease in platelet count can persist for more than 6 months after donation in patient population after donor right hepatectomy, such a change did not impact donor's safety.

Changes in spleen volume after resection of hepatic colorectal metastases

AIM

To identify and describe changes in spleen volume occurring in patients with colorectal metastases to the liver after partial hepatectomy.

MATERIALS AND METHODS

Forty-one consecutive patients (20 men, 21 women) with histopathology-proven colorectal liver metastases who underwent partial hepatectomy between August 2007 and April 2011 were included. Liver and spleen volumes were measured by computed tomography (CT) volumetry on the most recent CT prior to surgery and on all CTs obtained within a year after partial hepatectomy. Patients were carefully evaluated for and excluded if they had co-morbid conditions known to cause splenomegaly or risk factors for portal hypertension such as underlying liver disease and portal vein thrombosis.

RESULTS

Thirty-two (78%) patients demonstrated an increase in spleen volume on the first post-operative CT, with more than a double increase in volume amongst five patients. Spleen volume increased by an average of 43% within 3 months of partial hepatectomy (p < 0.0001) and remained increased through 6 months after surgery, returning to near baseline thereafter. In the remaining nine (22%) patients, the spleen was observed to decrease an average of 11% in volume on first postoperative CT (p < 0.005).

CONCLUSIONS

Splenic enlargement after partial hepatectomy of colorectal metastases is a common finding on CT. Increased familiarity amongst radiologists of this phenomenon as likely reflecting physiological changes is important in order to avoid unnecessary evaluation for underlying conditions causing interval enlargement of the spleen.

Randomized clinical trial of splenic radiofrequency ablation versus splenectomy for severe hypersplenism

BACKGROUND

Radiofrequency ablation (RFA) is a relatively new treatment for hypersplenism. The results of a randomized clinical trial comparing RFA and splenectomy with 5 years of follow-up are reported.

METHODS

Fifty-seven patients with hypersplenism due to liver cirrhosis were assigned randomly (in a 1 : 2 ratio) to splenectomy (19 patients) or RFA (38). The RFA group was subdivided according to the percentage of the spleen ablated: less than 50 per cent (9 patients), 50-70 per cent (18) or over 70 per cent (11). Routine blood tests were performed before and after operation, and total spleen volume and ablated volume were measured by contrast-enhanced computed tomography. The primary endpoint of the trial was recurrence of hypersplenism, assessed as platelet and white cell counts, at 5 years after surgery.

RESULTS

White cell and platelet counts increased rapidly after intervention in both groups. By 36 months after operation peripheral platelet and white cell counts had decreased significantly in the RFA group compared with the splenectomy group, and declined to baseline levels by 48 months. Hypersplenism recurred after 6 months in patients with less than 50 per cent of the spleen ablated. Blood cell count in the splenectomy group and in patients with more than 50 per cent of the spleen ablated decreased with time after operation, but to levels that remained significantly higher than those before operation (P < 0·050). Splenic volume reached its nadir 12 months after RFA and then increased with time.

CONCLUSION

Splenic RFA represents an attractive alternative treatment for hypersplenism induced by liver cirrhosis, particularly when more than 50 per cent of the spleen is ablated.

Platelet transfusion can be related to liver regeneration after living donor liver transplantation

BACKGROUND

Although liver regeneration is a fundamental aspect of living donor liver transplantation (LDLT), the factors that affect liver regeneration during the early post-transplantation period have not been thoroughly investigated. Recently it was suggested that platelets contribute to liver regeneration. The aim of the present study was to identify the major factors that affect liver graft regeneration during the early post-transplantation period.

MATERIALS AND METHODS

Eighty-seven right liver grafted, adult-to-adult LDLT patients were retrospectively analyzed. Liver regeneration was assessed by volumetry from computed tomographic (CT) scans obtained between the 9th and 11th postoperative days. The authors investigated relationships between clinical variables and liver graft regeneration rates, and they conducted multiple regression analysis on factors found to be significant by univariate analysis.

RESULTS

Mean graft weight at operation was 722.9 +/- 109.7 g, and mean graft volume assessed by follow-up CT was 1,042.2 +/- 155.6 ml, reflecting a mean liver graft regeneration of 45.9 +/- 22.3%. The graft regeneration was found to correlate inversely with graft-to-recipient weight ratio (GRWR, r = -0.406, p < 0.001) and directly with portal flow velocity (cm/s; r = 0.307; p = 0.004) and splenic index (cm(3); r = 0.282; p = 0.009). Moreover, the total amount (units) of platelets transfused was found to be significantly associated with graft regeneration (r = 0.293; p = -.006). Stepwise regression analysis showed that GRWR (beta = -33.124; p = 0.001), total amount of platelets transfused (beta = 0.771; p = 0.012), and splenic index (beta = -0.010; p = 0.049) were independently associated with graft regeneration.

CONCLUSIONS

The results of the present study suggest that platelets play a significant role in human liver regeneration after LDLT.

Effect of liver transplantation on spleen size, collateral veins, and platelet counts

BACKGROUND

The aim of this study was to evaluate the effect of liver transplantation on the spleen size, spontaneous splenorenal shunt (SRS) function, and platelet counts in patients with hypersplenism.

METHODS

Between December 2001 and February 2007, 462 adult patients underwent orthotopic liver transplantations (OLTX) at our institution. Of these patients, CT or MRI information was reviewed retrospectively in 55 patients. Volume measurements of the spleen and liver, spleen/liver volume ratio (S/L ratio), presence and size of SRS, and platelet counts were evaluated before and after OLTX.

RESULTS

Mean spleen volume decreased from 827 +/- 463 ml to 662 +/- 376 ml after OLTX (p < 0.01). Five (11%) patients returned to normal-range spleen size after OLTX. SRS was observed in 19 patients before OLTX (35%). The diameter of SRS also significantly decreased from 1.0 +/- 0.5 cm before OLTX to 0.7 +/- 0.5 cm after OLTX (p < 0.05). SRS disappeared in 16% of patients (3/19). S/L ratio significantly decreased from 0.65 +/- 0.33 to 0.38 +/- 0.17 (p < 0.01) after OLTX. Platelet counts significantly increased after OLTX (p < 0.01). Improvement of the platelet count in the group with postoperative S/L ratio >0.35 was not as good as that in the group with S/L ratio <0.35 (p < 0.01).

CONCLUSIONS

Spleen size and SRS size became significantly smaller after OLTX. However, patients with postoperative S/L ratio >0.35 tend to have lower platelet counts after OLTX.

Variations in Interferon Gamma Receptor Gene Expression during Liver Regeneration after Partial Hepatectomy in Rats

Cell-mediated immunity, which includes interferon gamma (IFN-γ) expression, is activated during the process of liver regeneration; however, the genetic pathway of this activation is still unclear. The present study evaluated variations in the interferon gamma receptor (IFN-γR) gene and its mRNA expression during liver regeneration after partial hepatectomy (PH). Male Wistar rats weighing approximately 200 g were subjected to PH (70 or 40%). IFN-γR gene expression in the remnant liver was measured by cDNA microarray, and mRNA expression was verified by real-time quantitative reverse transcription-polymerase chain reaction (Q-PCR) preoperatively and at 2, 4, 6,12, 24, and 72 hours and 7 days postoperatively. The ratio of remnant liver weight to body weight increased markedly after 70 per cent PH and more gradually after 40 per cent PH. It reached near 90 per cent of the preoperative level at 72 hours after PH in both groups. The scanned spots of the genomic survey on the cDNA microarray chips were uneven and increased irregularly in number and density after PH. IFN-γR gene expression increased markedly in a single peak pattern, up to more than double the preoperative level, at 6 hours after 70 per cent PH. The curve in the 40 per cent PH group was flat and peaked at only 1.6 times the preoperative level. The variations in IFN-γR-related mRNA expression were verified by Q-PCR. Elevations in IFN-γR gene and mRNA expression were shown during the early stage of liver regeneration after PH. The genetic pathway of IFN-γ/IFN-γR expression is activated during liver regeneration.

Two-year follow-up of splenic radiofrequency ablation in patients with cirrhotic hypersplenism: does increased hepatic arterial flow induce liver regeneration?

BACKGROUND

Hepatocyte hypoxia may be a mechanism determining abnormal tissue oxygenation and dysfunction of the cirrhotic liver. Since the introduction of radiofrequency ablation (RFA) for patients with cirrhotic hypersplenism, we observed a phenomenon of visible hepatic regeneration. This study aims to investigate the potential mechanism of RFA-induced liver regeneration, and the 2-year outcomes of splenic RFA.

METHODS

Forty patients who underwent splenic RFA for cirrhotic hypersplenism were followed for 24 months. Before and after RFA procedures, portal hemodynamics and liver and spleen volumes were measured by Doppler ultrasonography and computed tomography volumetry. Liver function tests and blood counts were also determined.

RESULTS

The splenic and portal venous flows decreased, but hepatic arterial flow (HAF) increased dramatically after the RFA procedure. Liver volumes at 3 month post-RFA increased compared to the baseline volumes (872 +/- 107 vs. 821 +/- 99 cm(3), P = .031). A correlation was found between maximum absolute values of liver volumes (triangle upliver volumes) and that of HAF (triangle upHAF) in Child-Pugh class A/B patients (r = 0.60; P < .001). Leukocyte and platelet counts, as well as liver function, improved substantially during the 2-year follow-up. Patients with > or = 40% of spleen volume ablated had better improvement of thrombocytopenia. No death or severe complications occurred.

CONCLUSIONS

RFA for cirrhotic hypersplenism is safe and efficacious. The increase in HAF as a result of splenic RFA may improve liver function and induce liver regeneration in cirrhotics, but further studies are necessary to clarify the underlying mechanisms.

Predictive factors for platelet increase after partial splenic embolization in liver cirrhosis patients

BACKGROUND AND AIM

Partial splenic embolization (PSE) is often performed for improving thrombocytopenia in cirrhotic patients. We investigated the largely unclear predictive factors for platelet increase at both 1 month and 1 year after PSE.

METHODS

Aimed at increasing the platelet count, PSE was performed in 42 cirrhotic patients with thrombocytopenia (platelets < 80 x 10(4)/mL) caused by hypersplenism. The clinical data were analyzed to clarify the predictive factors for platelet increase at 1 month (n = 42) and 1 year (n = 38) after PSE.

RESULTS

The mean splenic infarction ratio was 76.7% +/- 11.2%. The platelet count increased to 259% +/- 112% and 228% +/- 75% of the pretreatment values at 1 month and at 1 year after PSE, respectively. Stepwise multiple linear regression analysis showed that the infarcted splenic volume had a positive independent association with the increase in platelet count at both 1 month (P = 0.00004) and 1 year (P = 0.005) after PSE (increase in platelet count (x10(4)/mL): at 1 month = 0.752 + 0.018 x infarcted splenic volume (mL), R(2) = 0.344; at 1 year = 2.19 + 0.01 x infarcted splenic volume (mL), R(2) = 0.203). Receiver operating characteristic analysis yielded a cut-off value of 388 mL of infarcted splenic volume for achieving an increase of 5.0-8.0 x 10(4)/mL in platelet count at 1 year.

CONCLUSIONS

PSE can reduce the platelet pool and induce an increase in platelet count. This increase is greatly dependent on the infarcted splenic volume.

Extent of hepatectomy on splenic hypertrophy and platelet count in live liver donors

The extent of donor hepatectomy may affect splenic hypertrophy and platelet count. The subjects were 50 live liver donors. The ratio of the graft weight to total liver volume (GW/TLV) and the splenic hypertrophy ratio, expressed as the splenic volume one month after surgery divided by that before surgery, were calculated. The platelet count one month after surgery was divided by that before surgery to determine the rate of the platelet count decrease. The correlation of GW/TLV to the splenic hypertrophy ratio and the rate of the platelet count decrease were examined. The median (range) GW/TLV was 54 (28-71)%. The splenic hypertrophy ratio and the rate of the platelet count decrease was 133 (99-191)% and 92 (71-129)%, respectively. GW/TLV positively correlated with the splenic hypertrophy ratio (Spearman's correlation coefficient (r(s)) = 0.448, p = 0.001), and negatively correlated with the rate of the platelet count decrease (r(s) = -0.471, p < 0.001). Multivariate analysis revealed that GW/TLV influenced the splenic hypertrophy ratio [adjusted odds ratio (OR), 12.0; 95% confidence interval (CI), 1.32-9.04; p = 0.01] and the ratio of the platelet count decrease (adjusted OR, 11.6; 95% CI, 1.40-8.33; p = 0.01). Larger graft procurement might place living liver donors at higher risk for post-operative thrombocytopenia.

Liver Regeneration and Splenic Enlargement in Donors after Living-Donor Liver Transplantation

Liver regeneration after donor hepactectomy offers a unique insight into the process of liver regeneration in normal livers. As the liver restores itself, concurrent splenic enlargement occurs. There are many theories about why this phenomenon takes place: some investigators have proposed a relative portal hypertension that leads to splenic congestion or, perhaps, the presence of a common growth factor that induces both the liver and spleen to enlarge. Between the months of June 2001 and May 2004, 112 live donor liver transplants (LDLTs) were performed in Chang Gung Memorial Hospital, Kaohsiung, Taiwan. The total number of donor hepatectomies performed during this period was 113, however, because one of the cases required dual donors. Of our 113 donors, we eventually analyzed the data of 109; 4 patients were lost to follow-up 6 months later and were excluded from our study. The average age of our donor population was 32.32 +/- 8.48 years. The mean liver volume at donation was noted to be 1207.72 +/- 219.95 cm3, and 6 months later, it was 1027.18 +/- 202.41 cm3. Expressed as a percentage of the original volume, the mean liver volume 6 months after hepatectomy was 90.70% +/- 12.47% in this series. For right graft donors, mean liver volume after 6 months was 89.68% +/- 12.37% of the original liver volume, whereas that for left graft donors was 91.99% +/- 12.6%. Only 26 of the 109 (23.85%) donors were able to achieve full regeneration 6 months post-donation. Notably, liver function profiles of all donors were normal when measured 6 months after operation. The average splenic volume at donation as measured by computed tomography (CT) volumetry was 159 +/- 58 cm3, and the splenic volume 6 months post-donation was 213 +/- 85 cm3. There was a mean increment in splenic volume of 35% +/- 28% 6 months after donation. The blood profiles of the donors were monitored; particular attention was given to platelet levels and liver function tests, and these were found to be within normal limits 6 months after operation. Of note, splenic enlargement was significantly greater among right-sided donors than their left-sided counterparts. Greater splenic enlargement was also observed in those donors who achieved full liver regeneration at their evaluation 6 months postoperatively than in those who did not. Although original liver volume was not re-established in most patients 6 months after liver donation, there seemed to have been no untoward effects to the donor. The factors that affect liver regeneration are complex and myriad. Although there is splenic enlargement at 6 months post-donation in donors of LDLT, there are no untoward effects of this enlargement.