Effects of positive end-expiratory pressure on systemic haemodynamics, with special interest to central venous and common iliac venous pressure in liver transplanted patients

BACKGROUND AND OBJECTIVES

Positive end-expiratory pressure may alter cardiac function and systemic haemodynamics. As transplanted livers may be sensitive to liver congestion, the aim of our study was to evaluate the effect of positive end-expiratory pressure on the cardiovascular system and in particular on central venous and iliac venous pressure in liver transplanted patients.

PATIENTS AND METHODS

Seventy-two liver transplant patients were enrolled in this prospective, interventional study. On admission to our Intensive Care Unit all patients were ventilated in a biphasic positive airway pressure mode. Haemodynamic effects of three randomly set levels of end-expiratory pressures (0, 5 and 10 mbar) were studied in the immediate postoperative period in all patients. Mean arterial pressure, central venous pressure, pulmonary capillary wedge pressure, central iliac venous pressure and cardiac index were recorded and analysed at each of the three end-expiratory pressure levels.

RESULTS

The values of central- and wedge-pressure significantly increased with increased end-expiratory pressure. Central venous pressure increased by 24% and wedge pressure showed a 6% increase at 10 mbar in comparison to 0 mbar. The values for cardiac index and mean arterial pressure showed no statistically significant difference at 10 mbar as compared to 0 and 5 mbar. The mean pulmonary arterial and common iliac venous pressure were unaffected by different positive end-expiratory pressure levels.

CONCLUSIONS

Short-term pressure controlled ventilation with end-expiratory pressure up to 10 mbar does not significantly impair systemic haemodynamics in liver-transplanted patients. Further studies are needed to determine whether these findings could be confirmed with higher pressure levels and/or over a longer period of ventilation time.

The effects of cardamonin on lipopolysaccharide-induced inflammatory protein production and MAP kinase and NFkappaB signalling pathways in monocytes/macrophages

BACKGROUND AND PURPOSE

In this study we examined the effect of the natural product cardamonin, upon lipopolysaccharide (LPS)-induced inflammatory gene expression in order to attempt to pinpoint the mechanism of action.

EXPERIMENTAL APPROACHES

Cardamonin was isolated from the Greek plant A. absinthium L. Its effects were assessed on LPS-induced nitrite release and iNOS and COX-2 protein expression in two macrophage cell lines. Western blotting was used to investigate its effects on phosphorylation of the mitogen activated protein (MAP) kinases, ERK, JNK and p38 MAP kinase, and activation of the NFkappaB pathway, at the level of IkappaBalpha degradation and phosphorylation of NFkappaB. Also its effects on NFkappaB and GAS/GAF-DNA binding were assessed by EMSA.

KEY RESULTS

Cardamonin concentration-dependently inhibited both NO release and iNOS expression but had no effect on COX-2 expression. It did not affect phosphorylation of the MAP kinases, degradation of IkappaBalpha or phosphorylation of NFkappaB. However, it inhibited NFkappaB DNA-binding in both LPS-stimulated cells and nuclear extracts of the cells (in vitro). It also inhibited IFNgamma-stimulated iNOS induction and GAS/GAF-DNA binding.

CONCLUSIONS AND IMPLICATIONS

These results show that the inhibitory effect of cardamonin on LPS-induced iNOS induction is not mediated via effects on the initial activation of the NFkappaB or MAP kinase pathways but is due to a direct effect on transcription factor binding to DNA. However, although some selectivity in cardamonin's action is implicated by its inability to affect COX-2 expression, its exact mechanism(s) of action has yet to be identified.

[Surgical therapy of intrahepatic cholangiocellular carcinoma]

BACKGROUND

Intrahepatic cholangiocarcinoma (ICC) is the second most common primary hepatic malignancy. Tumor resection is the treatment of choice, but so far the value of hepatic resection has not been well defined. We report results with an aggressive surgical approach for the treatment of this tumor entity.

PATIENTS AND METHODS

Between April 1998 and June 2004, 54 liver resections were performed in 120 patients with ICC. In 24 patients, 39 additional procedures were performed: resection of hilar bifurcation (n=18), partial resection of diaphragm (n=6), vascular resection and reconstruction (n=15).

RESULTS

There were 30 R0, 21 R1, and three R2 resections. After R1/R2 resection and explorative laparotomy, the median survival times are 9 months and 6 months, respectively. Following R0 resection, the calculated median survival is 46 months, and the 1-, 3-, and 5-year survival rates are 83%, 58%, and 48%, respectively.

CONCLUSION

The presented data show that R0 resection leads to a significant prolongation of survival in patients with ICC. In contrast, incomplete tumor removal does not provide a survival benefit. These results justify an aggressive surgical approach to achieve a R0 resection. The low resectability rate of less than 50% underlines the need for improved preoperative staging.

Transoesophageal echocardiography: a useful tool to diagnose entrapment of pulmonary artery catheter

Placement of a pulmonary artery catheter during cardiac surgery is associated with various complications, one of which is entrapment. On the day following surgery unusual resistance was encountered while attempting to remove a pulmonary artery catheter from a patient who had undergone coronary artery bypass grafting. Entrapment of the catheter was confirmed by transoesophageal echocardiography, which demonstrated invagination of the free wall of the pulmonary trunk on gentle traction on the pulmonary artery catheter. Surgical exploration revealed that the catheter was transfixed by the suture used to close the pulmonary artery vent site. Surgical re-exploration and other potential complications related to catheter retrieval can be avoided if catheter entrapment is diagnosed intra-operatively. We suggest that a high index of clinical suspicion along with the use of intra-operative transoesophageal echocardiography is considered in situations where catheter entrapment is a possibility.

Unusual Manifestation of Posttransplant Lymphoproliferative Disorder in the Esophagus

Early manifestations of posttransplant lymphoproliferative disorders (PTLD) are mainly associated with a primary Epstein-Barr virus (EBV) infection. Rapid increases in peripheral blood EBV DNA load are supposed to reliably predict PTLD. We report a boy who 6 months after living-related kidney transplantation presented with an extranodal esophageal manifestation of PTLD. Despite a primary EBV infection with tonsillitis, the peripheral blood EBV DNA remained low, hiding the progression to PTLD.

Solid-state storage of Ag nanoparticles in anion exchange resin beads and their recovery

This paper reports the idea and describes a method of reversible storage and recovery of silver nanoparticles (NPs) in anion exchange resin beads based on the principle of ion exchange. We also report that similar exchange of NPs was not possible with cation exchange resins. The Ag NPs were stored by simple exchange of anions of the resins, which were activated with OH- and NO3- ions. FTIR spectroscopic measurements support that the Ag NPs were exchanged with NO3- ions in the resins. The so-stored NPs could be regenerated by addition of NaBH4 solution to the resins. These NPs were recovered and subsequently utilized for catalytic reduction of an organic dye (eosin). Powder X-ray diffraction (XRD) pattern indicated storage of the NPs in the form of various oxides of silver in the resin, with the peak value of intensity corresponding to XRD of the NPs not changing with time. Scanning electron microscopic measurements show that the NPs in the beads were stable for over a month without the formation of any apparent agglomeration.

Computer-gestützte Operationsplanung bei Leberlebendspenden

INTRODUCTION

The appropriate recipient/donor match is a prerequisite for successful living donor liver transplantation (LDLT). A precise knowledge of the liver anatomy and the functional liver volume plays a key role in allocating live liver donor candidates. With the new software HepaVision, we obtained information on liver mapping by means of virtual 3-dimensional non-invasive imaging reconstructions and were able to perform a virtual simulation of the liver transsection. Aim of our study was to investigate, whether this new computer technology is advantageous in surgery planning for LDLT.

METHODS

From January 2002 until December 2004 355 liver transplantations were performed in our department, of which 36 were LDLT. According to our evaluation protocol 135 potential donors (63 male, 72 female) between 18 to 59 years received preoperatively an all-in-one CT. The acquired data sets were further analysed with the software HepaVision (MeVis, Germany).

RESULTS

Of the 135 evaluated donors, we excluded 99 (73 %) from donation based on the HepaVision-data. Reason for exclusion was an inadequate liver volume (70.8 %) or a risk related anatomical anomaly (2.2 %). In the remaining 36 cases a successful graft donation was possible. There were no postoperative complications in the donors and recipients, directly related to a misjudgment of the anatomy or miscalculation of the liver volume.

CONCLUSION

The systematic use of HepaVision for surgery planning proved to be indispensable for proper donor selection. A virtual simulation of the liver transsection on 3D-model additionally increased the safety of the operation, consequently decreasing the risk for the donor.

Electrophoretic NMR studies of polymer and surfactant systems

The aim of this tutorial review is to introduce to a broader readership the emerging technique of electrophoretic NMR (eNMR). The "electrophoretic" element of the technique refers to the fact that charged particles are induced to flow by the application of an electric field. This flow is measured using pulsed-gradient spin-echo NMR (PGSE-NMR). The great potential of this experimental approach is the fact that NMR is chemically selective and non-invasive. eNMR, especially when combined with the more established PGSE-NMR experiment, may therefore be used to quantify the structure of multi-component systems via the dynamics and charge of each species within a complex mixture. Accordingly, eNMR is likely to be of great significance for colloid scientists, biologists, technologists and formulation scientists.

Molecular Chirality and Charge Transfer through Self-Assembled Scaffold Monolayers

The effect of molecular chirality on electron transmission is explored by photoelectrochemistry. Thiol-terminated chiral scaffold molecules containing a porphyrin chromophore were self-assembled on gold surfaces to form a monolayer. Incorporation of the SAM-coated gold into an electrochemical cell and illumination with visible light generated a cathodic photocurrent. When using circularly polarized light, the photocurrent displayed an asymmetry (different magnitude of photocurrent for right versus left polarization) that changed with the molecular chirality (left- or right-handedness of the scaffold). A symmetry constraint on the electronic coupling between the porphyrin and the organic scaffold is proposed as a possible mechanism for the photocurrent asymmetry.

Überkreuz-Lebendspende-Nierentransplantation in Deutschland

A donor kidney exchange or cross-over program with exchange of organs between two donor-recipient pairs offers a possibility to realise living donor renal transplantation in cases of ABO-blood group incompatibility. The German transplantation law demands, in contrast to other countries, a close personal relationship between living donor and recipient. In this paper, we propose a concept based on the generation of a close personal relationship between donor-recipient pairs that allows cross-over renal donor transplantation considering the statement of the responsible medical-ethical institutions and the German transplantation law.

Nuclear Magnetic Resonance and Small-Angle Neutron Scattering Studies of Anionic Surfactants with Macrocounterions: Tetramethylammonium Dodecyl Sulfate

Micellar solutions of tetramethylammonium dodecyl sulfate have been studied to determine the degree of counterion binding. Tetramethylammonium chloride was added over a wide range of surfactant concentrations such that the total concentration of tetramethylammonium ions in solution remained constant. Small angle neutron scattering experiments showed a constancy in aggregation number across this series, consistent with the constant C(aq) concept of Bales et al. (J. Phys. Chem. B 2001, 105, 6798). Pulsed-field gradient and electrophoretic NMR experiments were used to determine the degree of counterion dissociation, alpha, which was found to be 0.33. This value is in contrast to the value from conductivity measurements (alpha = 0.2), but supports the concept of an aggregation number based definition of alpha.

Anatomical and physiological classification of hepatic vein dominance applied to liver transplantation

BACKGROUND

Proper outflow reconstruction is essential in LDLT. Preoperative planning requires meticulous attention to hepatic vein dominance patterns. The purpose of our study was to provide a combined anatomical-physiological classification of hepatic vein dominance useful for surgical decision-making in both donors and recipients.

METHODOLOGY

We analyzed 3-dimensional CT-imaging reconstructions of 55 potential live liver donors evaluated at our Institution between January 2003 and May 2004.

RESULTS

Our data revealed that: 1) The middle hepatic vein (MHV) and left hepatic vein (LHV) show a relative lack of anatomical diversity, whereas the right hepatic vein (RHV) exhibits multiple variants, 2) 45% donors had inferior hepatic veins (IHV) with anatomically and physiologically relevant venous drainage territories, 3) The RHV is usually dominant when present as a single vein without anatomical IHV (type 1A), or when considered as a complex with IHV (type 1Bx) (80% vs. 88%), 4) Only 55% of dominant type 1Bx RHV/IHV-complex automatically included a dominant type 1By RHV by itself, 5) A single RHV out of anatomical complex with IHV (type 1By) was dominant in only 48% of our donor candidates, 6) The MHV types 2A and 2By are strongly dominant accounting for up to 57% of total liver volume (TLV).

CONCLUSIONS

We propose a new classification based on both anatomical and physiological hepatic venous configurations. Our model also provides a new nomenclature that can be universally applied to preoperative planning in LDLT.

Early versus delayed surgical treatment of open tibial fractures: effect on the rates of infection and need of secondary surgical procedures to promote bone union

The purpose of this study was to evaluate whether there was any significant difference in the rates of infection and of secondary surgical procedures to promote bone union, between early(6 h or less after arrival to hospital) and delayed(more than 6 h) surgical treatment of open tibial fractures. Three hundred and eighty-three open tibial fractures were evaluated. 184 fractures had early and 199 had delayed surgical treatment. The rates of infection and secondary surgical procedures to promote bone union of the two groups were compared with univariate and multivariate statistical methods. There was no statistically significant difference between early and delayed treatment groups with respect to overall infection (53/184 versus 51/199 infection rates, P = 0.96), deep infection (8/184 versus 8/199 infection rates, P = 1.0), and rates of secondary surgical procedures to promote bone union (24/184 versus 20/198, P = 0.77). We were unable to demonstrate any significant difference in infection rates or need of secondary procedures to promote bone union, between early and delayed surgical treatment of open tibial fractures.

Laryngospasm during subarachnoid block

Central neuraxial block is associated with increased vagal tone. We report a patient who developed laryngospasm and stridor under spinal anaesthesia. This was treated successfully with i.v. atropine and fluids. We propose that the laryngospasm was secondary to increased vagal tone under the spinal anaesthetic. Such a manifestation of increased vagal tone under spinal anaesthesia has not been reported previously.

Liver resection for hepatocellular carcinoma in non-cirrhotic liver without underlying viral hepatitis

BACKGROUND

Hepatocellular carcinoma (HCC) arising in normal liver parenchyma is rare and the outcome after hepatectomy is not well documented.

METHODS

Between June 1998 and September 2003, 33 patients without viral hepatitis underwent resection for HCC in a non-cirrhotic, non-fibrotic liver. Data were analysed with regard to operative details, pathological findings including completeness of resection, and outcome as measured by tumour recurrence and survival.

RESULTS

Twenty-three major hepatectomies and ten segmentectomies or bisegmentectomies were performed. After potentially curative resection, 19 of 29 patients were alive at a median follow-up of 25 months, with calculated 1- and 3-year survival rates of 87 and 50 per cent respectively. Survival was significantly better after resection of tumours without vascular invasion (3-year survival rate 89 versus 18 per cent; P = 0.024). Disseminated recurrence developed in nine of 29 patients, leading to death within 28 months of operation in all but one of the nine.

CONCLUSION

These data justify hepatic resection for HCC arising in non-cirrhotic, non-fibrotic liver without underlying viral hepatitis. Liver transplantation is rarely indicated because the outcome is good after resection of tumours without vascular infiltration, whereas vascular invasion is invariably associated with diffuse extrahepatic recurrence.

Staging laparoscopy in gastric cancer

BACKGROUND

As patients with gastric cancer are offered choices between surgical resection, neoadjuvant or palliative chemotherapy, or symptomatic relief alone, the need for accurate preoperative staging becomes apparent. Laparoscopy has been suggested as an appropriate staging modality in a variety of upper gastrointestinal malignancies.

METHODOLOGY

Staging laparoscopy was performed in 45 patients with potentially resectable gastric cancer as determined by physical examination, gastroscopy, endosonography, transcutaneous ultrasonography and current generation computed tomography. Conventional clinic staging and laparoscopic staging according to the Tumor-Node-Metastases classification of the International Union against Cancer were registered separately on a database. Results were then compared to evaluate the agreement of both staging procedures.

RESULTS

Compared to conventional staging, laparoscopy resulted in up staging of 23 patients (51.1%). In 10 patients of them peritoneal seeding was first found during laparoscopy, whereas additional liver metastases were detected in 3 patients and Krukenberg's tumor in one. As a consequence, the therapy planning was changed and laparotomy was avoided in 14 of these patients as the first operative procedure. Sensitivity of clinical staging was especially poor for stage IV tumors (5.3%) and for the majority of stage IIIB tumors (42.9%). Cytologic examination of peritoneal fluid had no additional information in our series.

CONCLUSIONS

The value of laparoscopy in staging patients with gastric carcinoma could be demonstrated in this study. It is a safe and effective staging modality, helping to avoid unnecessary laparotomies and providing new means of directing appropriate treatment strategy.

X-ray Absorption Spectromicroscopy Studies for the Development of Lithography with a Monomolecular Resist

Soft X-ray absorption microscopy was applied to image and characterize molecular patterns produced by electron irradiation of aliphatic and aromatic thiol-derived self-assembled monolayers (SAMs) on Au substrates. The measurements were performed at all relevant absorption edges. The fabricated patterns could be clearly imaged with a lateral resolution better than 150 nm, which, for example, allowed us to distinguish a fine structure of 1 microm features. The X-ray absorption microspot spectra derived from different areas of the SAM patterns provided specific chemical information on pristine and irradiated areas and unexpected features in these patterns. The quality of the microspot spectra is comparable with that of the analogous X-ray absorption spectra acquired with standard equipment from homogeneous SAMs. In particular, a chemical transformation of the functional tail groups within the irradiated areas of the patterned aromatic SAMs could be directly monitored.

Intracranial hypotension due to leakage of cerebrospinal fluid: could myelography be a therapeutic option?

Spontaneous intracranial hypotension (SIH) is an uncommon condition caused by cerebrospinal fluid leakage. We report of a 29-year-old woman with typical symptoms in whom initial cranial MRI and CT were normal . A clinical diagnosis of SIH, but the symptoms did not resolve with conservative therapy or a lumbar epidural blood patch. Repeat MRI revealed (indirect) findings consistent with SIH but failed to directly demonstrate a cerebrospinal fluid fistula. Subsequent CT myelography revealed leakage of contrast medium into the epidural space bilaterally along the nerve roots at C3-7. Following the myelography the patient reported dramatic clinical improvement with complete resolution of symptoms. The adhesive quality of the myelographic contrast medium might have precipitated closure of the meningeal tears. Myelography may be not only of diagnostic value but also therapeutic in SIH.

[Surgical and interventional treatment of liver metastases]

The liver is the most common target organ for metastatic disease. The majority of patients undergoing surgical treatment for liver metastases have colorectal primaries. Endocrine liver metastases, or metastases from other tumors such as mammary carcinoma, sarcomas, renal tumors or gastrointestinal stromal tumors (GIST) are appreciably less common for surgical treatment. The gold standard of treatment is resection of the metastatic lesions. In the meantime, advances in surgical techniques and improved perioperative patient management make it possible to perform extensive resections with acceptable morbidity and mortality rates. In the event of metastases that are not primarily resectable, various downstaging procedures are available, with the aid of which secondary resectability can be achieved. Among the interventional treatment options that should be applied only in palliative intent, radiofrequency ablation is in widespread use.

Organ protective management of the brain-dead donor

The adequate management of brain dead donors on an Intensive Care Unit (ICU) is one of the major key points for a successful transplantation of harvested organs. In addition to an invasive monitoring like in any other ICU patient these patients needs a meticulous attention to their hemodynamic. The early administration of desmopressin to treat diabetes insipidus, a differentiated use of fluid resuscitation and a distinct catecholamine support are special features of an appropriate basic treatment. The administration of corticoids has to be considered if a sufficient circulation can not be regained.