A surgical model for isolating the pig liver in vivo for gene therapy.

Several studies report results that suggest the need of vascularization blocking for efficient gene transfer to the liver, especially in nonviral gene therapy. In this study, we describe a surgical strategy for in vivo isolation of the pig liver, resulting in a vascular watertight organ that allows the evaluation of several gene injection conditions. The hepatic artery and portal, suprahepatic and infrahepatic cava veins were dissected. Then, liver vascularization was excluded for 5-7 min. In that time, we first injected 200 ml saline solution containing the p3c-eGFP plasmid (20 µg/ml) simultaneously through two different catheters placed in the portal and cava veins, respectively. Vital constants were monitored during the surgery to assess the safety of the procedure. Basal systolic/diastolic blood pressures were 92.8/63.2 mm Hg and dropped to 40.7/31.3 mm Hg at the end of vascular exclusion; the mean basal heart rate was 58 bpm, reaching 95 bpm when the blood pressure was low. Oxygen saturation was maintained above 98% during the intervention, and no relevant changes were observed in the ECG tracing. Peak plasma AST (aspartate aminotransferase) and ALT (alanine aminotransferase) levels were observed after 24 h (151 and 57 IU, respectively). These values were higher, but not relevant, in 60 ml/s injection than in 20 ml/s injection. Efficiency of gene transfer was studied with simultaneous (cava and portal veins) injection of eGFP gene at flow rates of 20 and 60 ml/s. Liver tissue samples were collected 24 h after injection and qPCR was carried out on each lobe sample. The results confirmed the efficiency of the procedure. Gene delivery differed between 20 ml/s (9.9-31.0 eGFP DNA copies/100 pg of total DNA) and 60 ml/s injections (0.6-1.1 eGFP DNA copies/100 pg of total DNA). Gene transcription showed no significant differences between 20 ml/s (15,701.8-21,475.8 eGFP RNA copies/100 ng of total RNA) and 60 ml/s (12,014-36,371 eGFP RNA copies/100 ng of total RNA). The procedure is not harmful for animals and it offers a wide range of gene delivery options because it allows different perfusion ways (anterograde and retrograde) and different flow rates to determine the optimal conditions of gene transfer. This strategy permits the use of cell therapy and viral or non-viral liver gene therapy, especially appropriated to a wide variety of inherited or acquired diseases because of the liver's ability to produce and deliver proteins to the bloodstream.

Indications for and results of liver retransplantation.

Liver retransplantation (LReTx) is the therapeutic option for the irreversible failure of a hepatic graft. Our aim was to evaluate the rate of and indications for LReTx and actuarial patient survivals. Among 1260 LTx were 79 LReTx (6.3%). During the first LTx, there were no apparent differences between patients who did or did not required LReTx. The most frequent reasons were hepatic artery thrombosis (31.6%), recurrence of the VHC cirrhosis (30.4%), and primary graft failure (21.5%). The actuarial survivals at 1 and 5 years were 83% and 69% among those without LReTx versus 71% and 61% among early LReTx, and 64% and 34% among late LReTx (P < .001). Although there exists high morbidity and mortality with LReTx, it seems that this therapeutic alternative continues to be valid for patients with early hepatic loss, but not when the graft loss was late. It becomes necessary to define the minimal acceptable results that patient can benefit from LReTx.

Selective Indication of T-Tube in Liver Transplantation: Prospective Validation of the Results of a Randomized Controlled Trial.

BACKGROUND AND AIMS: T-tube placement during choledochocholedochostomy (CCS) associated with liver transplantation (LT) remains controversial. This study was designed to validate the results of an earlier prospective randomized controlled trial (RCT) on use versus nonuse of the T-tube during CCS associated with LT. METHODS: Prospective cohort study. The primary outcome was the overall incidence of biliary complications (BCs). RESULTS: In total, 405 patients were included, and the median overall monitoring period was 29 months (interquartile range: 13-47 months). Selective use of the T-tube reduced BCs (23% vs 13%; P = .003), of which 75% were type IIIa or less in the Clavien-Dindo classification. The overall BC rate did not differ between patients with versus without T-tube placement. CONCLUSIONS: We confirmed that selective use of a rubber T-tube during CCS associated with LT, following the principles established in our prospective RCT, reduced the rate of BC by 10% without detriment, even after enrolling patients at an a priori greater risk of BCs than were the RCT patients.

Does Surgeon Fatigue Influence the Results of Liver Transplantation?

BACKGROUND: Recently, there has been an attempt to relate fatigue of the surgical team according to the start time of the transplant surgery and the surgeon's activity during the week, with the morbidity and mortality of liver transplant recipients. If this relationship could be demonstrated, it would be desirable to reconsider organization of transplant surgical teams. METHODS: We carried out a retrospective study of 439 successive cases of adult hepatic transplant from 2012 to 2016. We divided the patients into 2 groups, bearing in mind the interval between transplant procedures. Solitary liver transplantation was defined when >12 hours had elapsed since the last transplant, and consecutive liver transplant was defined when <12 hours had passed since the previous transplant. We analyzed the morbidity and mortality of the recipient (survival, vascular and biliary complications, early bleeding, and duration of surgery). Fatigue was measured as it related to the start time of the transplant, day of the week, and accumulation of daily and weekly activity of the surgical teams. RESULTS: No significant differences were found between the 2 groups with regard to donor or recipient characteristics. No variable related to the fatigue of the surgeons had an effect on the survival, biliary and vascular complications, early bleeding, or duration of the surgical intervention. CONCLUSION: We were unable to show that fatigue level of the surgical team influences the results of transplant procedures. Morbidity and mortality are likely related to other factors.

Prognostic Value of Pre-transplantation Serum Alpha-Fetoprotein Levels in Hepatocellular Carcinoma Recurrence.

Serum alpha-fetoprotein (AFP) value is still not included in the consensus guidelines to make decisions referring to liver transplantation (LT) for hepatocellular carcinoma (HCC). Many studies demonstrated the influence of high AFP level in poor prognosis after LT for HCC. We studied 301 consecutive recipients transplanted for HCC from January 2002 to December 2011. The median follow-up was 64.3 months (interquartile range, 41.6-90.8). HCC recurrence was 31.6% when AFP was >400 ng/mL and 50% when AFP was >1,000 ng/mL. Specificity to predict HCC recurrence was 95.1% (95% confidence interval [CI], 91.9-97.1) when AFP was >400 ng/mL and 98.9% (95% CI, 96.8-99.6) when AFP was >1,000 ng/mL. The overall survival (P = .008) and disease-free survival (P = .004) differed between patients groups when an AFP cutoff level of 1,000 ng/mL was used. The predictive accuracy of high pre-transplantation serum AFP level for HCC post-transplantation recurrence should be used in decision algorithms for LT.

[Thymoma. A retrospective study]. / Timomas. Estudio retrospectivo.

We review cases of thymic cell tumor treated between January 1991 and March 1998. Nineteen of the 23 cases studied involved thymoma. Eight (42%) were asymptomatic, 4 (21%) were associated with myasthenia gravis and 7 (37%) were symptomatic. The most common symptom was non-specific chest pain, reported by 4 (47%) patients with symptoms. Classifying the cases of thymoma by Masaoka's system, we found that 12 were cases of thymoma in stage I (63.2%), 4 in stage II (21.1%) and 3 in stage III (15.8%). No stage IV patients were treated. Treatment consisted of full exeresis of the tumor in 17 (89.5%) cases, partial resection in one case (5.2%) and biopsy of the tumor in one non-resectable, case. Adjuvant radiotherapy was applied in seven cases. Chemotherapy was not prescribed. With follow-up ranging from 9 to 96 months, half the patients survived 21 months after surgery. Among the surviving patients, mortality was nil at the end of the study. The results of microscopic, cytologic and blood analyses were of scarce value in differentiating between benign and malignant tumors, even though p53 and bcl2 antigen positivity and clinical stage have been related to poor prognosis in recent years.

Indications for and results of liver retransplantation.

Liver retransplantation (LRT) is the only therapeutic option for the irreversible failure of a hepatic graft. The aim of this study was to evaluate our rate, indications, postoperative morbidity and mortality and patient survival at one and 5 years after LRT. 1,260 liver transplants (LT) were performed between 1991 and 2006, 79 were LRT (6.3%). During the first LT, there were no apparent differences between patients who did or did not require LRT. The most common reasons for LRT were hepatic artery thrombosis (31.6%), recurrence of hepatitis C virus cirrhosis (30.4%) and primary graft non function (21.5%). The actuarial survival rates at one and 5 years were 83% and 69% among those without LRT versus 71% and 61% among those with early LRT, and 64% and 34% among those with late LRT (p < 0.001). Although high morbidity and mortality were associated with LRT, it seems that this therapeutic option is valid for patients with early hepatic loss, although not when the graft loss is late. It becomes necessary to define the minimal acceptable results so that patients can benefit from LRT.