Segment 4 and the left lateral segment regeneration pattern after resection of the middle hepatic vein in a living donor right hepatectomy.

BACKGROUND: Inclusion of the middle hepatic vein (MHV) with a right hepatectomy (RH) in live donor liver transplantation improves venous drainage of the anterior sector of the graft. Its long-term effects on donor left liver (LL) regeneration are not well described. METHODS: Donors who underwent RH with MHV (MHV+, n = 12) were compared with donors who underwent RH with preservation of the MHV (MHV-, n = 24). Peri-operative complications and volume of the entire liver and individual segments were evaluated at 1 year post-donation. RESULTS: There was a trend towards a higher complication rate in the MHV+ group (41% versus 25%), without reaching statistical significance (P = 0.3). Males, high body mass index (BMI) and a smaller residual liver volume (RLV) were predictors for greater LL regeneration. MHV+ donors had impaired regeneration of segment 4 (S4) at 1 year, and compensatory greater left lateral segment regeneration. The absence of venous drainage of S4 (V4) to left hepatic vein (LHV) was a predictor of impaired S4 regeneration. CONCLUSIONS: Regeneration of S4 is impaired in MHV+ donors. Caution should be taken when considering MHV removal on donors with dominant S4, especially on those with potential increased demand for liver regeneration, such as males, higher BMI and a smaller RLV.

Hepatoportal sclerosis: CT and MRI appearance with histopathologic correlation.

OBJECTIVE: The purposes of this study were to describe the spectrum of cross-sectional imaging findings of pathologically proven hepatoportal sclerosis and to compare the features of advanced and nonadvanced hepatoportal sclerosis. MATERIALS AND METHODS: Eighteen patients with a histopathologic diagnosis of hepatoportal sclerosis who had concurrent MRI or CT images participated in the study. The following imaging features were assessed: presence of liver nodularity and liver lesions, portal vein patency, presence and degree of portal hypertension, liver volume, and caudate-to-right lobe ratio. These features were compared between patients who underwent transplant and those who did not. RESULTS: The 18 patients (11 men and one boy, six women; mean age, 46.5 years) had hepatoportal sclerosis confirmed with liver biopsy (14 patients) or explant (four patients). Fourteen patients underwent contrast-enhanced MRI, and five underwent CT. The imaging findings were as follows: liver surface nodularity, five patients (all four transplant, one nontransplant) (p = 0.0016); evidence of portal hypertension, 17 patients; increased caudate-to-right lobe ratio, 16 patients; high periportal signal intensity on T2-weighted images, six patients; portal vein occlusion with cavernous transformation, five patients. The transplant patients had smaller pretransplant liver volume than did nontransplant patients (p < 0.04). CONCLUSION: Hepatoportal sclerosis is characterized by caudate lobe hypertrophy and right hepatic lobe atrophy, preserved liver volume, and lack of the liver nodularity associated with portal hypertension. In advanced cases, liver nodularity and atrophy produce an imaging appearance indistinguishable from that of cirrhosis.

Decreased Tongue Volume Post Radiation.

OBJECTIVES: To evaluate volume changes within the tongue post chemoradiation therapy (CRT). STUDY DESIGN: Retrospective review. SETTING: Academic Medical Center. SUBJECTS AND METHODS: Subjects included 19 patients that received CRT as the primary treatment for tonsillar or hypopharynx squamous cell carcinoma. Tongue volumes were calculated by three raters from thin slice computed tomography images collected before treatment and up to 29 months post-CRT. Body mass index (BMI) was also collected at each time point. RESULTS: Inter-rater reliability was high with an ICC of 0.849 (95% CI = 0.773, 0.905). Linear mixed effects modeling showed a mean decrease of 0.45 cm3 (standard error of the mean [SEM] = 0.11) in tongue volume per month post-CRT (P < .001). However, the addition of BMI to the model was significant (χ2 (4) = 25.0, P < .001), indicating that BMI was a strong predictor of tongue volume, with a mean decrease of 1.75 cm3 (SEM = 0.49) in tongue volume per unit decrease in BMI (P < .001) and reducing the post-CRT effect on tongue volume decrease per month to 0.23 cm3 (P = .02). BMI significantly (P < .001) decreased by 0.11 units (SEM = 0.02) per month post radiation. CONCLUSION: Tongue dysfunction and decreased tongue strength are significant contributors to the dysphagia that patients experience after receiving CRT. In this study, both tongue volume and BMI decreased post-CRT; therefore, BMI could potentially be used as a predictor of tongue volume post-CRT.

Live Donor Renal Anatomic Asymmetry and Posttransplant Renal Function.

BACKGROUND: Relationship between live donor renal anatomic asymmetry and posttransplant recipient function has not been studied extensively. METHODS: We analyzed 96 live kidney donors, who had anatomical asymmetry (>10% renal length and/or volume difference calculated from computerized tomography angiograms) and their matching recipients. Split function differences (SFD) were quantified with technetium-dimercaptosuccinic acid renography. Implantation biopsies at time 0 were semiquantitatively scored. A comprehensive model using donor renal volume adjusted to recipient weight (Vol/Wgt), SFD, and biopsy score was used to predict recipient estimated glomerular filtration rate (eGFR) at 1 year. Primary analysis consisted of a logistic regression model of outcome (odds of developing eGFR>60 mL/min/1.73 m(2) at 1 year), a linear regression model of outcome (predicting recipient eGFR at one-year, using the chronic kidney disease-epidemiology collaboration formula), and a Monte Carlo simulation based on the linear regression model (N=10,000 iterations). RESULTS: In the study cohort, the mean Vol/Wgt and eGFR at 1 year were 2.04 mL/kg and 60.4 mL/min/1.73 m(2), respectively. Volume and split ratios between 2 donor kidneys were strongly correlated (r = 0.79, P < 0.001). The biopsy scores among SFD categories (<5%, 5%-10%, >10%) were not different (P = 0.190). On multivariate models, only Vol/Wgt was significantly associated with higher odds of having eGFR > 60 mL/min/1.73 m (odds ratio, 8.94, 95% CI 2.47-32.25, P = 0.001) and had a strong discriminatory power in predicting the risk of eGFR less than 60 mL/min/1.73 m(2) at 1 year [receiver operating curve (ROC curve), 0.78, 95% CI, 0.68-0.89]. CONCLUSIONS: In the presence of donor renal anatomic asymmetry, Vol/Wgt appears to be a major determinant of recipient renal function at 1 year after transplantation. Renography can be replaced with CT volume calculation in estimating split renal function.

A prospective study of growth and rupture risk of small-to-moderate size ascending aortic aneurysms.

OBJECTIVE: The natural history of small-to-moderate size ascending aortic aneurysms is poorly understood. To follow these patients better, we have developed a method to objectively and reproducibly measure ascending aortic volume on the basis of gated contrast computed tomography scans. METHODS: From 2009 to 2011, 507 patients were referred for management of ascending aortic aneurysms. A total of 232 patients (46%) with small-to-moderate size aneurysms who did not have compelling indications for operation had measurement(s) of ascending aortic and total aortic volume; 166 patients had more than 1 scan, allowing measurement of growth. A total of 66 patients admitted to the emergency department without ascending aortic pathology served as a reference group. RESULTS: None of the patients experienced rupture, dissection, or death; 3 patients ultimately underwent operation. Ascending aortic volume and volume/total aortic volume differed for the surveillance and reference groups: 132.8 ± 39.4 mL versus 78.0 ± 24.5 mL; 38.3% ± 7.4% versus 29.1% ± 3.9%, respectively (both P < .001). Diameters at the sinotubular junction and mid-ascending aortic were 4.1 ± 0.6 cm and 4.4 ± 0.6 cm, respectively, for the surveillance group and 3.0 ± 0.4 cm and 3.2 ± 0.4 cm, respectively, for controls. The increase in ascending aortic volume was 0.95 ± 4.5 mL/year and 0.73% ± 3.7%/year (P = .007 and .012, respectively). Analysis of risk factors for ascending aortic growth revealed only the use of antithrombotic medication as possibly significant. CONCLUSIONS: Computed tomography volume measurements provide an objective method for ascertaining aortic size and monitoring expansion. Patients with small-to-moderate ascending aortic aneurysms who are carefully followed and managed appropriately have slow aneurysm growth and a small risk of rupture or dissection. Annual computed tomography screening may not be indicated, and elective resection-absent other surgical indications-is not necessary. The rupture/dissection risk for even larger aneurysms in carefully followed patients may be lower than currently believed.

Predicting the risk for acute type B aortic dissection in hypertensive patients using anatomic variables.

OBJECTIVES: This study sought to identify possible anatomic predictors of acute type B aortic dissection (AAD) in hypertensive patients using multidetector computed tomography angiography (CTA). BACKGROUND: Although hypertension remains one of the most significant risk factors for AAD development, it is unlikely to be the only risk factor for AAD. Few studies have assessed anatomical predictors of AAD development. METHODS: CTA of normotensive patients without AAD (group 1, n = 35), hypertensive patients without AAD (group 2, n = 37), and hypertensive patients with AAD (group 3, n = 37) were compared. The length, diameter, volume, and tortuosity of the aorta as well as arch vessel angulation were measured for each patient and normalized to group 1 averages. Stepwise logistic regression identified significant anatomical associations; the model was validated based on 1,000 bootstrapped samples. RESULTS: The demographics of the groups were similar. The length of the proximal and entire aorta, the diameters in the proximal ascending aorta and aortic arch, and the aortic volumes were all greater (p < 0.0001, p = 0.0064 for ascending aortic diameter) in group 3 than in groups 1 and 2, as was entire aortic tortuosity (p < 0.0001). An AAD risk model was developed based on aortic arch diameter, length from the aortic root to the iliac bifurcation, and angulation of the brachiocephalic artery origin from the aorta. The bootstrap estimate of the area under the receiver operating curve was 0.974. CONCLUSIONS: Enlargement of the ascending aorta and aortic arch and increased aortic tortuosity reflect an aortopathy which enhances the probability of AAD. A model based on 3 anatomical variables demonstrates significant associations with AAD: it may allow identification by aortic imaging of the hypertensive patient most at risk, and permit implementation of aggressive medical management and consideration of pre-emptive surgery to prevent dissection.

Right hepatectomy for living donation: role of remnant liver volume in predicting hepatic dysfunction and complications.

BACKGROUND: Extensive attention has been placed on remnant liver volume (RLV) above other factors to ensure donor safety. METHODS: We performed a retrospective review of 137 right hepatectomies in live donors between June 1999 and November 2010. RESULTS: Median right lobe volume was 1,029 cm(3), which correlated with its actual weight (r = 0.63, P < .01); median RLV was 548 cm(3). Of the donors, 32 (24%) developed postoperative hepatic dysfunction (bilirubin >3 mg/dL or prothrombin time >18 s on postoperative day 4). RLV did not predict postoperative hepatic dysfunction (P = .9), but it was associated with peak international normalized ratio (INR) (P = .04). Donor age and male gender were predictors of increased bilirubin at postoperative day 4 (age, P = .03; gender, P = .02). Of the donors, 45 (33%) experienced complications, and 24 donors had RLVs <30%; 42% experienced complications compared to 31% of donors whose RLVs were greater than 30% (P = .3). Cell-saver utilization and aspartate-aminotransferase (AST) levels (OR = 3) were associated with complications. Volumetric assessment can predict RLV accurately. CONCLUSION: Although no demonstrable association between RLV <30% and complications was found, an RLV of 30% should remain the threshold for donor safety. Age and gender should be balanced in donors with a near threshold RLV of 30%. Surgical complexity, suggested by the need for intraoperative autoinfusion of blood and postoperative levels of AST, remained the independent predictor of complications.