[Radiation exposure of the eye lens in orthopedics and trauma surgery : A pilot study]. / Strahlenbelastung der Augenlinse in O&U : Eine Pilotstudie.

BACKGROUND: On 27 June 2017 the Act on new regulation of the law for the protection against the harmful effects of ionizing radiation was passed. One of the main innovations in daily surgical practice in the now legally stipulated provisions is the lowering of the eye lens dose to 20 mSv/year (§§ 78, 212 Radiation Protection Act, StrlSchG). MATERIAL AND METHODS: To estimate the level of exposure of the eye lens to ionizing radiation that is to be expected in the course of surgical interventions, the dose that surgeons receive during surgery was determined. For this, the radiation exposure adjacent to the eye lens was measured using a forehead dosimeter while performing surgical interventions over a period of 8 weeks in 2 different operating rooms. RESULTS: As a result, a mean estimated eye lens radiation dose Hp (3) of 190 µSv could be determined during the 2­month study period. Thus, the estimated cumulative radiation dose in 1 year of approximately 1.2 mSv was significantly below the threshold of 20 mSv/year. CONCLUSION: By complying with the common radiation protection measures in the context of operative interventions in orthopedics and trauma surgery, the legal limit value of 20 mSv/year is generally not expected to be exceeded.

STAT-1 decoy oligonucleotide improves microcirculation and reduces acute rejection in allogeneic rat small bowel transplants.

During acute rejection leukocyte-endothelial cell interaction fuelled by costimulatory molecules such as the CD40/CD154 receptor/ligand dyad disrupts microcirculation of the small bowel. Downregulating endothelial CD40 expression by employing a decoy oligonucleotide (dODN) neutralizing the transcription factor signal transducer and activator of transcription-1 (STAT-1) may protect the graft. Therefore allogenic small bowel transplantation was performed in the Brown Norway to Lewis rat model. Graft vessels were pretreated with STAT-1 dODN, mutant control ODN (20 microM) or vehicle (n=8). CD40 antisense ODN and scrambled control ODN-treated transplants served as target control (n=3 each). Intravital microscopy, histology, immunohistochemistry and Western blot analyses were performed 7 days later. Functional capillary density, red blood cell velocity and perfusion index in STAT-1 dODN and CD40 antisense ODN-treated transplants were improved whereas stasis index was reduced. Leukocyte-endothelial cell interaction showed no difference. Histological parameters of rejection, infiltrating CD3-positive cells and apoptotic bodies were also reduced in STAT-1 dODN and CD40 antisense ODN-treated transplants 7 days post-transplantation. CD40 protein abundance was reduced to less than 10% of control in STAT-1 dODN-treated grafts. STAT-1 dODN blockade of CD40 expression improves mucosal perfusion, reduces graft rejection, T-cell infiltration and apoptosis in rat small bowel allografts during acute rejection.

[Relaparoscopy as an alternative to laparotomy for laparoscopic complications]. / Relaparoskopie bei laparoskopischen Komplikationen.

In the field of visceral surgery, complications requiring reintervention following laparoscopy are currently most likely to be approached with conventional laparotomy. However, relaparoscopy has the theoretical advantage of maintaining the reduced morbidity allowed by the first procedure. Essential to the success of relaparoscopy is a clear understanding of the various specific complications. Should the surgeon decide on relaparoscopy, then prompt action is of central importance. Following laparoscopic cholecystectomy, it is fundamentally technically possible through renewed laparoscopy to treat not only subhepatic abscesses but also smaller lesions of the bile duct, for example from the gall bladder fossa. Revision of complications following fundoplication is technically very demanding and should be performed only by those most experienced in the techniques of laparoscopy. In contrast to interventional drainage, relaparoscopy of abscesses following laparoscopic appendectomy has the theoretical advantage of allowing recognition and treatment of the causes, for example in the case of appendicular stump insufficiency. Relapses very shortly after endoscopic surgery of inguinal herniae result from erroneous technique and may be corrected endoscopically in most cases. Complications following colon surgery have so far been dealt with using open surgery for technical reasons and also for patient safety. Given the uncertainty in the literature, patient safety must be paramount, when deciding on which technique is best to employ, particularly in cases of haemorrhage.

Predicting postoperative morbidity by clinical assessment.

BACKGROUND: The aim of this study was to determine the accuracy of prediction of the surgeon's 'gut-feeling' in estimating postoperative outcome. METHODS: A prospective series of 1077 consecutive patients undergoing major hepatobiliary or gastrointestinal surgery were studied. Patients having elective (n = 827) and emergency (n = 250) procedures were included. The surgeon predicted the development of postoperative complications immediately after completion of surgery on a scale from 0 to 100 percent. These predictions were compared with the actual outcome and with predictions made using the Physiological and Operative Severity Score for the enUmeration of Mortality and morbidity (POSSUM). The Portsmouth predictor equation (P-POSSUM) was applied for the estimation of mortality. RESULTS: The observed morbidity and mortality rates were 29.5 and 3.4 percent respectively. POSSUM predicted a morbidity rate of 46.4 percent and P-POSSUM a mortality rate of 6.9 percent. The surgeon's gut-feeling was more accurate in the prediction of morbidity at 32.1 percent. On the basis of gut-feeling, surgeons overpredicted morbidity in elective surgery, but underestimated the risk of complications in the emergency setting. The (P)-POSSUM scoring system overpredicted morbidity and mortality for elective and emergency operations. CONCLUSION: The surgeon's gut-feeling is a good predictor of postoperative outcome, especially after elective surgery. (P)-POSSUM overpredicted morbidity and mortality in this series of major gastrointestinal and hepatobiliary operations.

Acute impairment of hepatic microcirculation and recruitment of nonparenchymal cells by intrasplenic hepatocyte transplantation.

BACKGROUND/PURPOSE: Over the last 20 years, hepatocyte transplantation (HcTx) has advanced from the experimental to the clinical stage. To date, HcTx has been performed in 30 patients in the United States. Regardless whether hepatocytes are transplanted into the spleen and migrate to the liver or are injected directly into the portal vein, transplanted liver cells will, to some extent, congest the recipient liver microcirculation. The potential negative consequences of intrasplenic HcTx were the subject of this study. METHODS: By using intravital microscopy, the authors investigated whether intrasplenic HcTx of 20 x 10(6) allogenic hepatocytes would influence liver perfusion, excretory liver function, and nonparenchymal cells (Kupffer and Ito cells) in vivo. RESULTS: The sinusoidal perfusion rate declined significantly from 94% (control) to 84% on day 1 and 76% on day 7. Bile acid excretion decreased in a similar fashion from 0.924 mg/h (control) to 0.669 mg/h on day 7. The authors observed a significant increase of Ito cells from 81.1 cells per microscopic field (control) to 97.1 (day 1) and an increase of Kupffer cells (KC; 6.1 cells per microscopic field on day 1 v 3.8 on control). CONCLUSIONS: This study shows an acute impairment of hepatic microcirculation and hepatucellular function along with an recruitment and activation of nonparenchymal cells in the early posttransplantation period after intrasplenic HcTx. Kupffer cell recruitment indicates an activation of local host defense, and Ito cell activation implies the initiation of liver repair mechanisms owing to ischemia-related cell damage.

Microcirculation and excretory function of the liver under conditions of carbon dioxide pneumoperitoneum.

BACKGROUND: To date, the effects of increased abdominal pressure, as given during carbon dioxide (CO(2)) pneumoperitoneum, on hepatic microcirculation and biliary excretion are unknown. METHODS: Using a custom-made peritoneal cavity chamber, we performed intravital microscopy of the left liver lobe under conditions of CO(2) pneumoperitoneum in a rat model. In addition, biliary excretion was assessed. RESULTS: The establishment of a CO(2) pneumoperitoneum of 4 or 8 mmHg resulted in sinusoidal perfusion failure that was more pronounced in the periportal regions than in the midzonal and pericentral regions of the liver acinus. Biliary excretion was considerably reduced at an intraabdominal pressure of 8 mmHg. Leukocyte-endothelial cell interactions increased significantly in both hepatic sinusoids and postsinusoidal venules. CONCLUSION: Alterations in hepatic microcirculation and liver function must be taken into consideration in any kind of laparoscopic surgery and may be of particular clinical relevance in patients with liver pathology.

[Mesenteric ischemia. Is diagnostic laparoscopy of value?]. / Mesenteriale Ischämie. Hat die diagnostische Laparoskopie einen Stellenwert?

In the past decade laparoscopic surgery replaced many open operations in general surgery. Apart from therapeutic uses in cholecystectomy, appendectomy, hernia surgery, gastric fundoplication, and increasingly also large intestine surgery, it is indicated diagnostically first of all for unclear abdominal findings and for staging of intra-abdominal malignancies. To date laparoscopy has been used occasionally for diagnosis and therapy of mesenteric ischemia. Patients suffering from mesenteric ischemia are usually old and have comorbid conditions. Quick diagnosis and therapy are necessary due to the pathogenesis of the disease. The low rate of morbidity as well as the easy availability of laparoscopy in principle favor the employment of laparoscopy also for mesenteric ischemia. Against the background of increasing experience in the area of laparoscopic surgery, this study gives an overview of the present value of laparoscopy for mesenteric ischemia.

Effect of laparotomy and CO(2) pneumoperitoneum on tumor growth of human colon carcinoma and expression pattern of tumor-associated proteins in the SCID mouse.

BACKGROUND AND AIMS: The impact of laparoscopy on tumor progression is still unclear. This study investigated the effect of CO(2) pneumoperitoneum on the intra-abdominal growth of human colon carcinoma independently of the effect of the immune system. METHODS: SCID mice underwent either median laparotomy or laparoscopy. Human colon carcinoma cells were implanted into the upper abdomen. The control group was not operated on following cell injection. Tumor growth and the protein expression pattern of proliferation marker Ki67, cell-cell adhesion molecules E-cadherin, alpha- and beta-catenin, and cell-extracellular matrix adhesion molecules CD44 v5 and v6 in tumor tissue were analyzed on postoperative day 14. RESULTS: Total tumor volume in the laparoscopy group significantly exceeded that in the laparotomy group. Immunohistochemistry revealed reduced expression of alpha-catenin and elevated expression on beta-catenin and CD44 v5 in the tumor tissue of the laparoscopy group. CONCLUSION: The expression pattern of proteins associated with tumor progression and the increase in tumor growth suggest an increased risk of laparoscopy at least for the growth of advanced human colon carcinoma.

A peritoneal cavity chamber for intravital microscopy of the liver under conditions of pneumoperitoneum.

BACKGROUND: Intravital microscopy allows direct visualization of the hepatic microvasculature. We report on a novel application of this technique using a chamber model that simulates the conditions of pneumoperitoneum. METHODS: For this purpose, we designed a peritoneal cavity chamber for rats. In the present study, we evaluated the technical procedure without any induction of increased intraabdominal pressure to assess undisturbed hepatic microcirculation. Intravital microscopy of the liver was performed in 12 rats. Animals that underwent the same operative procedure without the chamber served as controls (n = 12). RESULTS: Hepatic sinusoidal perfusion rate, leukocyte-endothelial cell interaction, and bile flow showed no significant differences between the groups. Operating time was longer in the chamber group. CONCLUSION: The peritoneal cavity chamber is an attractive approach for the study of hepatic microvascular, cellular, and molecular mechanisms that are important to our understanding of the potential harmful effects of laparoscopy on hepatic circulation and liver function.

[Laparoscopic stoma technique]. / Laparoskopische Stomaanlage.

Laparoscopic stoma creation may be performed as an independent intervention, in combination with local anorectal procedures or as a part of complex laparoscopic intestinal operations. With the exception of specialized methods to preserve continence, every type of stoma formation can be performed laparoscopically. Indications for laparoscopic fecal diversion do not differ from open surgery. Apparent advantages are the limitation of the laparotomy to the location of the stoma, rapid return of bowel function and less postoperative discomfort and morbidity, especially when intestinal diversion is required as an independent procedure. Previous surgery is not a contraindication for the laparoscopic procedure. However, dense adhesions may compromise the ability to identify the bowel segment to be exteriorized and require adhesiolysis. Therefore, the risk of intra- and postoperative complications and the frequency of conversions (reported between 4.1 and 15.7%) is increased in patients with previous surgery. The overall rate of complications reviewed in the literature, including stoma-related problems, seems to be similar or superior to conventional laparotomy. Still, laparoscopic enterostomies are not routinely performed in most institutions. Presently available data are limited and randomized trials have not been performed. We recommend the use of laparoscopic techniques for fecal diversion in patients with intestinal obstruction requiring palliative treatment and in patients with high probability for future abdominal surgery, e.g. in Crohn's disease.

[Ileus of the large intestine as a late sequela of direct diaphragmatic rupture]. / Der Dickdarmileus als Spätfolge einer direkten Zwerchfellruptur.

We report two patients who were administered to our hospital with an obstruction of the colon. 4 months ago one of the patients had suffered a penetrating wound with a knife in the upper left abdomen. The other patient was wounded by gunshot in the left thorax 50 years ago. The x-ray of the lung showed the ruptured diaphragm as a sharp line in the left thorax and the enema with contrast fluid revealed a stop at the left colonic flecture. In both cases the rupture of the diaphragm was closed via an abdominal approach, the inspection of the colon did not discover any defect. The postoperative course was uneventful. In contrast to other authors we believe that the delayed rupture of the diaphragm in connection with a colonic obstruction should be repaired by an abdominal access.

Human colorectal cancer: high frequency of deletions at chromosome 1p35.

Cytogenetic analyses of human colon cancer cells have revealed a high frequency of chromosome 1p deletions among other chromosomal abnormalities. In order to find out whether these chromosomal alterations are manifestations of loss of genetic material, we surveyed DNA of 62 primary tumors, 7 metastases, and matching peripheral blood cells with a panel of polymorphic DNA probes that detect different loci on chromosome 1p. A portion of the probes was derived from a microclone bank generated by microdissection and microcloning of 1p35----pter DNA. In 42% of the colon carcinomas allelic loss was observed with at least one probe. The deletions were of different sizes but always included a region involving band 1p35, except for two tumors in which allelic loss was detected more proximally. The frequency of 1p deletion in the metastases was higher than in the primary tumors. These data indicate that genetic information related to tumorigenesis is located within or nearby region 1p35 and that deletion of this region occurs later in tumor development. Our results add to the number of genetic changes presumably involved in colon cancerogenesis.