Biomedical subjects

H Lang

Publications and source records attributed to H Lang.

At least 19 recordsLinked to original sources

PubMed2007

Preoperative volume prediction in adult living donor liver transplantation: how much can we rely on it?

Accurate preoperative prediction of functional donor and remnant hemiliver volumes in live donor liver transplantation is essential in preventing postoperative liver failure and optimizing safety. Our aim was (1) to evaluate volume variability associated with multiphasic CT imaging and (2) to determine over- or under-estimations of 3-D CT graft-volume assessments based on 'largest' versus 'smallest' CT phases with respect to intraoperative findings. Native, arterial and venous phase CT images from 83 potential live liver donors were subject to 3-D CT liver volume calculations and virtual 3-D liver partitioning. Estimates were compared to intraoperative volumes obtained in 43 cases. Calculated (preoperative) graft-volume-body-weight-ratios (GVBWR) versus measured (intraoperative) graft-weight-body-weight-ratios (GWBWR) were analyzed. Significant differences in total liver volume- and in graft-liver volume calculations were found among the largest (venous) and smallest (native) CT phases. High significant overestimations were observed in graft-volume determinations and in GVBWR-calculations based on the 'largest' CT phase when compared to intraoperatively obtained graft-weight and -GWBWR values. In contrast, differences among intraoperative measurements and preoperative calculations based on the 'smallest' CT phase yielded less significant overestimations. While 3-D CT volumetry based on the 'largest' (venous) CT phase is associated with considerable overestimation, 3-D volumetry based on the 'smallest' (native) CT phase accurately matches the intraoperative findings.

Donor Selection↗

PubMed2007

[Management of iatrogenic esophageal perforations].

BACKGROUND: Iatrogenic esophageal perforations are still a life-threatening clinical entity. PATIENTS AND RESULTS: We present the case reports of six patients to demonstrate different treatment options and we focus on new therapeutic strategies which have evolved in the interdisciplinary management of iatrogenic esophageal perforations. Two patients with perforations in the cervical esophagus were operated and in another patient the perforation was closed with fibrin glue. Three patients with perforations in the thoracic esophagus were treated with self-expandable plastic stents. CONCLUSION: The surgical therapy of esophageal perforations still is regarded to be the gold standard and nonadherence should only be considered based on interdisciplinary decisions in individual cases. However, positive results are increasingly being reported for conservative endoscopic treatment, particularly for thoracic perforations.

Adult↗

PubMed2007

[Liver resection and transplantation for hepatic tumors].

Hepatic surgery has made substantial advances in the last two decades due to technical developments and improvements in perioperative management. This has reduced surgery dependent mortality to less than 5%, and provides the possibility of carrying out more substantial hepatic resections and to interpret the indications more liberally, also for tumours localized unfavorably. A widely standardized surgical technique as well as new possibilities for organ conservation and, in particular, immunosuppression mean that given suitable indications, liver transplantation is today regarded as a routine procedure for the treatment of hepatocellular carcinoma. This work provides an overview of the current status of surgical therapy for the most frequent, benign liver tumours, as well as for hepatocellular and cholangiocellular carcinoma.

Adenoma, Liver Cell↗

PubMed2007

Computer-assisted operative planning in adult living donor liver transplantation: a new way to resolve the dilemma of the middle hepatic vein.

An adequate venous outflow is essential for securing viability of both graft and remnant in adult living donor liver transplantation (ALDLT). Seventy-five potential live liver donors were evaluated for LDLT by means of an "all-in-one" CT, which defined the biliary tree, portal vein, hepatic artery, and hepatic vein anatomy. The acquired data sets were further analysed by means of the software HepaVision (MeVis, Germany). Only a minority (29%) of potential donors were found to have a vascular and biliary anatomy consistent with the classically described "normal" patterns. The vast majority (71%) had "anatomical variations". Thirty-nine (52%) donors underwent ALDLT hepatectomy. The right hepatic vein was dominant in 64 cases, representing 48 +/- 6% of the total liver volume (TLV). The middle hepatic vein was dominant in 11 cases, making up 40 +/- 8% of the TLV. The left hepatic vein was never dominant. The volume contribution of the middle hepatic vein (MHV) was 114-782 ml for the right and 87-419 ml for the left hemiliver. Computer-assisted planning allows for the 3D reconstruction of the vascular and biliary anatomy, automatic calculation of the total and territorial liver volumes, and risk analysis of hepatic vein dominance relationships. This comprehensive data acquisition supports preoperative evaluation and provides a high degree of safety for donors and improved outcomes for recipients.

Adolescent↗

PubMed2006

Liver transplantation for hepatocellular carcinoma in patients beyond the Milan but within the UCSF criteria.

AIM: Liver transplantation (LT) is the best therapy for early hepatocellular carcinoma (HCC) in cirrhosis. Whereas the Milan criteria are routinely applied, the University of California San Francisco (UCSF) criteria are occasionally considered in large-volume transplant centers. Poor information is available about the real "gain" in patients' outcome when extending the listing criteria from Milan to UCSF. PATIENTS AND METHODS: Out of 100 patients transplanted for HCC at our center, 4 patients exceeding the Milan but meeting the UCSF criteria were identified. Data of these patients were analysed for the purposes of this study. RESULTS: Three of them are currently alive after a median follow up of 57 months. One patient died 20 months post-transplant as a result of complications from hepatitis. Of the three who are alive, one underwent surgery for HCC recurrence 81 months post transplant. The remaining two have no evidence of tumor 56 and 57 months post transplant, respectively. CONCLUSION: Our results, as well as the reviewed literature, showed that only a small percentage of transplanted HCC patients can be classified as "beyond Milan-within UCSF". These patients seem to have acceptable overall, as well as recurrence free survivals. Large-volume patients' series, intention- to-treat analysis based on the radiological findings and multi-center prospective studies are required, in order to further explore the outcome of patients "beyond Milan-within UCSF" criteria and in order to better define the risk/benefit ratio of a potential expansion of the current listing criteria.

Adult↗

PubMed2006

The "territorial belonging" of the middle hepatic vein: a troublesome dilemma in adult live donor liver transplantation--anatomical evidence based on virtual 3-dimensional-computed tomography-imaging reconstructions.

BACKGROUND: The venous drainage of the liver plays an essential role in securing viability of both graft and remnant in live donor liver transplantation (LDLT). There is still controversy on whether the middle hepatic vein (MHV) should be routinely included as part of the graft or retained with the remnant liver. The purpose of this study was to analyze hepatic venous drainage patterns based on information obtained by 3-dimensional CT-imaging reconstructions. METHODOLOGY: Fifty five potential live liver donors were evaluated between January 2003 and May 2004 at our Institution. We analyzed two anatomical definitions of liver dominance: total liver dominance (TLD) and hemiliver dominance (HLD). The following concepts were addressed: 1) Hepatic vein territories, 2) Hepatic vein dominance relationship, 3) Territorial belonging- patterns of the MHV to the right and left hemilivers, additionally an analysis of venous outflow in the central liver sectors was performed. RESULTS: Our results showed that: 1) The definitions of dominance: TLD vs. HLD overlap, displaying the MHV belonging, by taking into account the individual right hepatic vein (RHV) variability; 2) A dominant RHV for the whole liver indicates that the RHV is also dominant in the right hemiliver; 3) The MHV belongs predominantly to the left hemiliver (LHL); 4) The left hepatic vein (LHV) is dominant in the LHL. CONCLUSION: Both dominance definitions provide independent mappings of the liver and offer helpful insight into venous dominance relationship.

Adult↗

PubMed2006

[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.

Bile Duct Neoplasms↗

PubMed2006

[Surgical therapy of hilar cholangiocarcinoma].

Surgical resection provides the only chance of cure for patients suffering from hilar cholangiocarcinoma. Due to the central anatomic localization within the liver hilum, established guidelines of oncologic surgery are difficult to apply. Resection of the hilar bifurcation alone or in combination with limited hepatic resection can be performed with low morbidity and low mortality but shows a high rate of local tumor recurrence. Usually, extended resection is required to achieve adequate safety margins. Right trisectionectomy complies best with the basic rules of oncologic surgery while allowing the maximum safety margin. The 5-year survival rates reported after right trisectionectomy range between 20% and 40% and reach 59% in selected patients. The increasing experience with living donor transplantation and recent advances in neoadjuvant tumor therapy may lead to renewed discussion of liver transplantation in hilar cholangiocarcinoma.

Bile Duct Neoplasms↗

PubMed2006

[Diffuse uptake of brown fat on computed-tomography coupled positron emission tomoscintigraphy (PET-CT) for the exploration of extra-adrenal pheochromocytoma].

We report an observation of strong bilateral uptake on a PET-CT scan compatible with activation of brown adipose tissue in a patient with extra-adrenal pheochromocytoma. A 42-year-old man was hospitalized for hypersudation together with weight loss and palpitations. Heart rate was 120 bpm and fasting blood glucose 1.36 g/l. Endocrine explorations revealed elevated serum chromogranine which reached 517 ng/ml (19-38). The norepinephrine level reached 49.7 nmol/l (<4.00) and urinary norepinephrine and normetanephrine levels reached 13977 nmol/24h (<414) and 32 micromol/24h (0.4-2.5) respectively. The thoraco-abdominal and pelvic scan showed a 6 cm diameter paraaortic hypervascularized mass with an infiltrative lesion of both perirenal area and mediastinal tissue without adenopathies. The abdominal MRI revealed the mass with a low intensity signal in T1 and a slight high intensity signal in T2. MIBG and octreoscan scintigraphies were negative. 18F-DG PET showed intensed uptake in the tumor mass together with intense, diffuse and bilateral uptake above and below the diaphragm. The mass was resected. Histological examination of the surgical specimen confirmed the diagnosis of extra-adrenal pheochromocytoma with an index of 13% cellular proliferation without cell atypia. There was a hypervascularization with small islets of brown adipose tissue in the perirenal fat. Both plasmatic and urinary catecholamines decreased to the normal range after the operation and PET-scan normalized. Bilateral spread of the radiotracer uptake was probably due to brown adipose tissue activation by excessive sympathetic stimulation induced by catecholamines released by the tumor.

Abdominal Neoplasms↗

PubMed2006

[Computer-assisted planning in living donor liver operation].

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.

Adolescent↗

PubMed2006

Successful sealing of benign esophageal leaks after temporary placement of a self-expanding plastic stent without fluoroscopic guidance.

INTRODUCTION: We report on our experience with the temporary use of a self-expanding plastic stent (SEPS) in the treatment of non-malignant esophageal leaks. MATERIAL AND METHODS: Between November 2001 and May 2005 ten patients with iatrogenic esophageal perforations (n = 4), post-surgical leaks (n = 5) and esophago-mediastinal fistulas after caustic injury (n = 1) were treated by temporary SEPS placement. In eight out of ten patients SEPS placement was done without fluoroscopy due to the emergency setting. Stent removal was performed with a rat-toothed forceps. RESULTS: Leaks were located in the proximal (n = 1), middle (n = 6) and distal (n = 3) parts of the esophagus. The mean leakage size was 2 cm. Stent placement without fluoroscopy was always successful. The median duration of stent therapy was 55.5 days (range 15,438). In 7/10 cases the SEPS was readily removed, showing complete healing of the former leak. Four patients died during the follow-up. However, their deaths were not related to the stent therapy. DISCUSSION: The temporary use of the SEPS represents a safe method for sealing benign esophageal leaks. In the emergency-setting SEPS placement without fluoroscopy is feasible and the stent can be easily removed. In contained perforations without severe mediastinitis of the mid esophagus the SEPS should be discussed as a gentle first-line therapy.

Esophageal Perforation↗

PubMed2006

Impact of endodontic treatments on the rigidity of the root.

The destabilizing effect of endodontic treatment upon teeth is still controversial. The purpose of this study was to investigate the effects of different steps of endodontic treatments upon the rigidity of teeth. Extracted untreated central maxillary anterior teeth were loaded (3.75 N), and deformations of the root were assessed by Speckle pattern interferometry. The following treatments (with subsequent determination of deformability) were conducted sequentially: access preparation, manual instrumentation (Kerr files ISO-40, ISO-60, ISO-80, ISO-110), and tapered and parallel-sided post preparation. It was found that the teeth were increasingly destabilized by any treatment. While the increased deformability was not significant with the manual enlargement (p > 0.05), we found a significant destabilization after access preparation and post preparation (p < 0.05). A corresponding difference was found after conversion of the post preparation from tapered to parallel-sided (p < 0.05). Both substance loss and modifications of the natural root canal geometry play an important role in tooth rigidity.

Bicuspid↗

PubMed2005

Disease course after liver transplantation for hepatocellular carcinoma in patients with complete tumor necrosis in liver explants after performance of bridging treatments.

AIM: To study the disease course of patients with hepatocellular carcinoma (HCC) showing complete tumor necrosis in their liver explants after undergoing bridging treatments followed by liver transplantation (LTx). PATIENTS AND METHODS: We evaluated data corresponding to 10 patients with liver cirrhosis undergoing bridging treatments for HCC prior to LTx. In all cases there was complete tumor necrosis in the explanted livers. RESULTS: There were 8 men and 2 women. Percutaneous radiofrequency ablation (RFA) was performed under computed tomographic guidance in 4 patients. The remaining 6 patients underwent transarterial chemoembolization (TACE). Five of them received one session of TACE, while the remaining one received a series of 4 sessions prior to LTx. Six patients had solitary nodules with a median diameter of 3.5 cm (range 2.5-4.2 cm). Four of them underwent RFA. Segmental tumor chemoembolization was performed in 2 patients. The remaining 4 patients had 2 tumors each with a median total diameter of 4.4cm (range 4.2-6.0 cm) prior to TACE. They underwent bilobar hepatic chemoembolization, which under staged the tumors prior to live donor liver transplantation (LDLTx). Six patients underwent deceased donor orthotopic liver transplantation. LDLTx was performed in 4 patients. Median waiting time to LTx was 53 days. All patients are alive without recurrence after a median follow-up of 19 months. CONCLUSION: Achievement of 100% tumor necrosis by means of bridging treatments followed by LTx for HCC is characterized by a very low recurrence rate and should receive further consideration and study.

Adult↗

PubMed2005

Pi-conjugated N-heterocyclic compounds: correlation of computational and electrochemical data.

Electrochemical reduction potentials of a broad selection of nitrogen-containing molecules suitable as bridging (dipodal and tripodal) ligands in coordination and organometallic chemistry are reported and compared with results of semiempirical calculations. Trends of electrode potentials observed experimentally agree with respective calculated data, deviations can be explained by invoking peculiarities of the involved molecular orbitals and ligand-electrode surface interactions.

Journal Article↗

PubMed2005

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.

Adolescent↗

PubMed2005

Ouabain induces apoptotic cell death in type I spiral ganglion neurons, but not type II neurons.

Application of ouabain to the intact round-window (RW) membrane of the gerbil cochlea induces apoptosis in most spiral ganglion neurons (SGNs), leaving a few neurons intact (Schmiedt et al. 2002). Here, physiological measures and immunostaining were used to examine the process of SGN degeneration at 3, 6, 12, and 24 h, 4 days, and 1 and 5 months after ouabain treatment. The few remaining neurons surviving up to 5 months after ouabain treatment were immunoreactive for peripherin, a type II neuron marker. Peripherin-positive cell counts indicate that about 7% of the SGNs in the gerbil cochlea are type II neurons, and these neurons survive intact after ouabain treatment. Ouabain exposure had little effect on the outer hair cell and lateral wall systems, even after a 5 month loss of auditory-nerve function. The cellular locations of cytochrome c, poly (ADP-ribose) polymerase (PARP), and activated caspase 3 were examined in control and ouabain-treated cochleas. A redistribution of cytochrome c in peripherin-negative (type I) neurons was observed at 3 h after ouabain exposure. Degraded PARP and activated caspase 3 were also detected in peripherin-negative SGNs at 6 and 24 h after treatment, respectively. These results suggest that the redistribution of cytochrome c is an early event during apoptosis in type I SGNs and that activation of PARP and caspase 3 are associated with apoptosis in these cells. Calcineurin and NF-kappaB are two important signaling pathways that may modulate cell survival in the central nervous system. Here, we found that calcineurin and NF-kappaB selectively labeled type II neurons. It is speculated that the high levels of calcineurin and NF-kappaB in type II SGNs, as compared with type I SGNs, may play protective roles in enhancing the survival of type II neurons exposed to ouabain.

Animals↗

PubMed2005

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.

Adult↗

PubMed2005

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.

Adult↗