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J Weitz

Publications and source records attributed to J Weitz.

At least 19 recordsLinked to original sources
PubMed2006

[Scope and limitations of diagnostics in breast disease--focussing on large core biopsy].

Percutaneous high speed large core biopsy (LCB) using a 14-gauge-needle, supported by sonographic procedures, is a safe and reliable method for the diagnosis of benign and malignant breast lesions in daily practice. All malignant diagnoses (B5)--comprising 44 % (267/604) of cases--were confirmed by subsequent surgical biopsy. This indicates a positive predictive value of 100 %. Evidence for uncertain dignity in LCB (categories B3 and B4) was found in 3 % of our cases (20/604), requiring open breast surgery for further clarification. This is strongly supported by the fact that 22 % of B3 and 82 % of B4 cases were identified as carcinomas in subsequent surgery. In 9 % of our cases (53/604), histology was only questionably representative (category B1) without cancer in the follow-up. In the B2-category--which comprised nearly 44 % of all cases (n = 263)--the positive predictive value ranged at 2 %. For clinical investigation, mammography, breast ultrasound and LCB the sensitivity were at 79 %, 92 %, 92 % and 98 %, respectively. The specificity of clinical findings, mammography, breast ultrasound and LCB ranged at 88 %, 67 %, 79 % and 99 %, respectively. The combination of the 3 methods: clinical findings, mammography and breast ultrasound (leading to a "total diagnostic score" provided a sensitivity and specificity of 97 % and 52 %. LCB revealed an excellent specificity of 99 %. Therefore, large core biopsy takes up a definite and reliable place in procedures of breast diagnostics, thereby preventing a high number of unnecessary open surgical interventions.

Adolescent↗
PubMed2006

[Importance of anesthesia in multimodal oncologic therapeutical concepts].

Patients with malignant diseases are increasingly being treated with multimodal therapeutical concepts based on the three major modalities surgery, radiotherapy and chemotherapy. The perioperative period is crucial within this multimodal concept as the prognosis of patients may be directly influenced by perioperative measures. In addition, it is of major importance to avoid complications in the perioperative phase, as these might worsen the prognosis of the patient and in order to prevent a delay in the beginning of planned adjuvant therapies. These aspects demonstrate the important role of anesthesia in the treatment of patients with cancer. Further studies defining the relevance of anesthesiologic measures in oncologic patients are needed.

Aged↗
PubMed2006

[Percutaneous large core breast biopsy].

Percutaneous large core biopsy of the breast with a 14-gauge needle, supported by sonographic and mammographic procedures, shows a high degree of safety during the collection for benign and malignant lesions. All malignant diagnoses (B 5) with a portion of 44% (267/604) were confirmed surgically, whereby the typing with 79% and grading with 58% were congruent. In 3.3% (20/604), there was uncertainty (B 3 and B 4), with the necessity for further clarification by open biopsy. This was supported by the fact that in 10/16 operated cases carcinoma was found. In the B 2-category, with a portion of nearly 44% (264/604), four cases of cancer were verified--not due to a wrongly negative histology but to non-representative material. In 8.8% (53/604), a questionable representative histology (B 1) occurred, but no cancer was found after surgical intervention (n=7). The indication for surgery is not only the punch biopsy result, but additionally negative histology and suspect or malignant clinical findings.

Biopsy↗
PubMed2006

Evaluation of microperfusion disturbances in the transplanted liver after Kupffer cell destruction using GdCl3: an experimental porcine study.

BACKGROUND: Organ function after liver transplantation is determined by ischemia-reperfusion injury. Destruction of Kupffer cells with gadolinium chloride (GdCl3) has been shown to have a possible preventive effect on the extent of this injury, which can be extrapolated by analyzing the distribution of hepatic microperfusion. The aim of this study was to evaluate the protective effect of GdCl3 on disturbances of microperfusion in the transplanted liver. METHODS: Landrace pigs were randomly divided into three groups. In the control group (CG; n=6) a mapping of the native liver was conducted. For mapping, the four hepatic liver lobes were named from right to left with A to D and every lobe was divided into three vertical segments (cranial, medial, and caudal). In each of these 12 areas, microperfusion was quantified using a thermodiffusion probe (TD [mL/100 g/min]). The other two groups were considered as transplanted treated group (TTG; n=10) and transplanted nontreated group (TnTG; n=10). The TTG received an infusion of 20 mg/kg GdCl3 intravenously 24 hours before organ harvesting. Then standardized orthotopic liver transplantation was performed. In TnTG, standardized orthotopic liver transplantation was carried out without prior GdCl3 injection. In the recipients, the microperfusion of transplanted livers were mapped in both TnTG and TTG, in two different time points (1 hour [n=5] and 24 hours (n=5]) after reperfusion. RESULTS: A significant reduction of macrophages in the TTG livers in comparison to the CG and TnTG livers was observed (P<.05). However, the number of macrophages in CG and TnTG livers showed no significant difference (P>.05). Regarding liver microperfusion, in TnTG, a marked heterogeneity was detected in the livers after reperfusion. Significant differences between liver lobes (horizontal planes; P=.032) and vertical layers of intralobar liver parenchyma (P=.029) were observed. The same pattern was seen in TTG livers after reperfusion and a significant difference between horizontal (P=.024) and vertical layers (P=.018) of liver tissue were observed. Comparing intralobar regional flow data between vertical planes 24 hours after reperfusion still showed a prominent variation of hepatic tissue perfusion in TnTG livers (P=.028). Within the same horizontal layers, no significant differences between lobes were measured anymore (P=.16). Contrary to TnTG, in TTG, a homogenous pattern of regional liver tissue perfusion was recorded 24 hours after reperfusion. Comparison of TD data on the liver regions showed no significant microperfusion differences in either horizontal (P=.888) or vertical (P=.841) layers. CONCLUSIONS: Application of GdCl3 resulted in a significant reduction of Kupffer cells. Twenty four hours after transplantation microperfusion showed a homogeneous pattern, which constituted an earlier and better recovery of the transplanted liver. Therefore, destruction of Kupffer cells reduced ischemia-reperfusion injury and seemed to be responsible for the early recovery of microperfusion disturbances and thus for an improvement of graft function.

Animals↗
PubMed2006

[Fiction and facts about multi-modal therapy in rectal cancer].

The prognosis of patients with rectal cancer has been improved significantly after introduction of the total mesorectal excision (TME). Just by performing TME, the local recurrence rates could be decreased to less than 10 %, independent of multi-modal therapeutic concepts. In contrast, the local recurrence rate reached 4 to 55 % (median 20 %) in a German multicenter study in 1995 prior to the nationwide introduction of TME. The goal of this overview is to compare the different concepts in the multi-modal therapy of rectal cancer with their advantages and disadvantages based on the current literature. Mentioned will be local recurrence rates and survival, but also toxicity, costs and acceptance of patients. Furthermore, a preview is given about future developments.

Antineoplastic Agents↗
PubMed2006

The role and value of sirolimus administration in kidney and liver transplantation.

Enormous advancements in visceral transplantation have led to significant improvements in the quality of life of patients. However, despite these developments, the average graft half-life after transplantation has remained almost unchanged and chronic rejection is still considered a major problem. In this regard, more concerns have shifted to factors influencing long-term graft survival, patient survival, and quality of life. To achieve this goal, detrimental effects of immunosuppressive (IS) agents, which have deleterious influence on the quality of life and/or patient survival, should be reduced. In the course of recent years, the transplant community has worked on reducing these side effects by developing new ISs, employing new combination regimens, or finding and adjusting optimal dosages and blood level concentrations. Among the IS agents, the antifungal, antitumoral and IS activity of mammalian target of rapamycin (mTOR) inhibitors without nephrotoxicity, have received special attention regarding this new class of IS. Sirolimus (SRL), as the first member of mTOR inhibitors, has been utilized in many clinical trials with respect to its benefit-risk assessment. In our review, the clinical evolution of SRL, as well as the evidence-based clinical benefits of SRL in kidney and liver transplantation (KTx, LTx), are summarized. Various studies of SRL in KTx and LTx have shown that combination therapy with SRL will enrich the variety of IS modalities. It also can be regarded as a safe base therapy to which other necessary drugs can be added. In addition to the enhanced acute rejection prophylaxis, and in contrast to the calcineurin inhibitors (CNI) and steroids, this drug solely does not have common side effects such as nephrotoxicity, neurotoxicity, diabetes mellitus and hypertension. Moreover, this agent might diminish vasculopathic processes that mediate chronic allograft nephropathy (CAN). Therefore, by reducing the likelihood of CAN it can decrease the rate of long-term organ failure. One possibly desirable characteristic of SRL is its antiproliferative effect, which could provoke antitumoral or antiatherogenic activity following transplantation. Despite all promising impacts of SRL in organ transplantation, there are some concerns regarding the adverse effects of this drug, for instance dyslipidemia, pneumonitis and wound healing problems. However, the majority of these side effects can be reduced or ceased by careful dose adjustments and correct timing of use. In conclusion, after a decade of both in vivo and in vitro studies on SRL, it can be advocated that SRL is a promising, potent and effective IS agent as it reduces the rate of acute rejection episodes in de novo transplants. It could improve the quality of life, graft and patient survival rate, and achieve excellent outcomes with few adverse effects when wisely used in combination with other immunosuppressants.

Graft Rejection↗
PubMed2006

How to increase inflow in liver transplantation.

Liver transplantation (LTx) has become the treatment of choice for selected cases of benign and malignant liver disease. Despite becoming increasingly safer in recent years this procedure still incurs several serious postoperative complications. The most significant surgical complications are related to surgical technique, particularly the reconstruction and/or anastomosis of the hepatic artery. Arterial hypoperfusion may lead to graft failure, sepsis, or ischemic biliary lesions. In this review we focus on the Achilles' heel of LTx: the hepatic artery. We provide transplant surgeons with an overview of the technical options that are available to increase arterial inflow and subsequently improve patient outcome. We exemplify some of the discussed techniques using a liver transplant case with an eventful postoperative course because of arterial complications.

Adult↗
PubMed2006

Wound complications following kidney and liver transplantation.

Advances in surgical techniques and immunosuppression (IS) have led to an appreciable reduction in postoperative complications following transplantation. However, wound complications as probably the most common type of post-transplantation surgical complication can still limit these improved outcomes and result in prolonged hospitalization, hospital readmission, and reoperation, consequently increasing overall transplant cost. Our aim was to review the literature to delineate the evidence-based risk factors for wound complications following kidney and liver transplantation (KTx, LTx), and to present the preventive and therapeutic modalities for this bothersome morbidity. Generally, wound complications are categorized as superficial and deep wound dehiscences, perigraft fluid collections and seroma, superficial and deep wound infections, cellulitis, lymphocele and wound drainage. The results of several studies showed that the most important risk factors for wound complications are IS and obesity. Additionally, there are surgical and/or technical factors, including type of incision, reoperation, and surgeon's expertise, as well as comorbidities such as advanced age, diabetes mellitus, malnutrition, and uremia. Preventive management of wound complications necessitates defining their etiological factors so that their detrimental effects on healing processes can be addressed and reduced. IS modalities and agents, especially sirolimus (SRL), and steroids (ST) should be adjusted according to the patient's co-existing risk factors. SRL should be administered three months after transplantation and ST should be tapered as soon as possible. A body mass index (BMI) lower than 30 kg/m2 is advisable for inclusion in a transplantation program, but higher BMIs do not exclude recipients. Surgical risk factors can be prevented by applying precise surgical techniques. Therapeutic modalities must focus on the most efficient and cost-effective medications and/or interventions to facilitate and improve wound healing.

Humans↗
PubMed2006

Laparoscopic surgery for colorectal cancer.

Traditionally open surgical resection has been recommended for colorectal tumours, but recently, laparoscopic surgery has gained popularity. This review summarizes the published data on laparoscopic colorectal cancer surgery with emphasis on recently published trials. For colon cancer laparoscopic resection appears to be associated with the same outcome as open surgery. However, whilst short-term outcome was better in the laparoscopic group in most of the randomized trials, when comparing laparoscopic with fast-track open surgery, no differences could be demonstrated in a randomized control trial. For rectal cancer the data are less clear. It seems that it may be feasible to resect at least small rectal cancers laparoscopically. Clearly the role of the laparoscopic technique needs to be better defined in rectal cancer. It has been well documented that short- and long-term outcome of colorectal cancer surgery depends on the quality and experience of the team treating the patient. Therefore, the major future challenge in laparoscopic colorectal cancer surgery will be to provide and structure adequate training and introduce quality control measures.

Colectomy↗
PubMed2006

Specific immune recognition of pancreatic carcinoma by patient-derived CD4 and CD8 T cells and its improvement by interferon-gamma.

Pancreatic carcinoma is a very aggressive disease and little is known about its immunobiology. We here describe the presence in pancreatic cancer patients of spontaneously induced functional CD4 and CD8 memory/effector T cells reactive to autologous tumor cells or to the pancreatic cancer associated antigen, MUC-1. Such specific cells were present in the bone marrow or peripheral blood of most of the 23 tested patients. Low dose stimulation of primary cultures of pancreatic cancer cells with 500 IU/ml IFN-gamma for 72 h enhanced HLA-I expression and induced the de novo expression of HLA-II molecules. This led to a much better immune recognition by autologous HLA-I restricted and purified CD8 T cells and allowed tumor cell recognition by HLA-II restricted purified CD4 T-helper cells. Thus, interferon-gamma appears to be a useful adjuvant cytokine to enhance the immunogenicity of a patients' tumor cells and their recognition by tumor reactive immune cells.

Aged↗
PubMed2005

The transverse coloplasty pouch.

BACKGROUND: The introduction of the total mesorectal excision (TME) and the use of modern staplers have improved outcome and increased the rate of sphincter-preserving low anterior resections in rectal cancer. Consequently, the interest in functional results after rectal reservoir reconstruction increased significantly. METHODS: A review of the current literature was conducted on the development of colon pouch procedures with a particular focus on the transverse coloplasty pouch compared with the colon J-pouch and other current techniques of reconstruction after TME such as the side-to-end anastomosis. RESULTS: The colon J-pouch (CJP) became the "gold standard" for rectal reservoir reconstruction owing to better early functional results compared with the straight coloanal anastomosis (CAA). However, 30% of the patients with CJP faced late evacuation problems requiring the chronic use of enemas or laxatives. This rate could be decreased by shortening the limb of the CJP from 8-10 to 5-6 cm, but the late evacuation problems remained in approximately 10% of the patients. An overview of the current knowledge on technical and functional aspects as well as indications and results of the transverse coloplasty pouch (TCP) is presented. CONCLUSION: The TCP was developed to provide early functional results comparable to the CJP while avoiding the late evacuation problems. Functional results after TCP, small colon J-pouch and side-to-end anastomosis are similar. Evacuation problems after TCP have not been reported.

Colectomy↗
PubMed2005

Laparoscopic restorative proctocolectomy.

BACKGROUND: Restorative proctocolectomy is increasingly being performed using minimally invasive surgery. In published series laparoscopically assisted techniques have usually included a suprapubic incision to enable major parts of the operation to be done openly. METHODS: Fifty consecutive patients with familial adenomatous polyposis or ulcerative colitis underwent laparoscopic restorative proctocolectomy using only a small perumbilical incision of 4 cm or less for vascular dissection and pouch formation; all other steps were performed entirely laparoscopically. Logistic regression was used for statistical analysis. RESULTS: In four patients (8 per cent) the operation was converted to an open procedure. The diagnosis of ulcerative colitis was associated with a higher overall rate of complications (P = 0.011), and an increased body mass index (BMI) with a higher rate of major complications (P = 0.050). The occurrence of wound infection was related to the diagnosis of ulcerative colitis (P = 0.049). Conversion resulted in greater blood loss (P = 0.004), but not in a higher complication rate. No patient required a blood transfusion. Patients with an increased BMI and those taking immunosuppressive therapy had a longer hospital stay (P = 0.043). CONCLUSION: Laparoscopic restorative proctocolectomy is technically feasible. Patients with ulcerative colitis and increased BMI have a higher risk of complications. This minimally invasive technique may reduce the need for perioperative blood transfusion.

Adenomatous Polyposis Coli↗
PubMed2005

Guidelines for prevention and management of complications following kidney transplantation in rats.

Kidney transplantation in rats is a useful model for microsurgery, transplantation, and immunology studies. Our aim was to analyze various techniques of kidney transplantation in rats with emphasis on guidelines for the prevention and management of complications. Complications were categorized into general, vascular, and urological types and respectively attributed to long transplantation time, core body temperature drop, nonreplaced intraoperative blood loss, anastomosis failure, and ureteral anastomoses with stents or cannulas, which increase the risk of calculus formation. In conclusion, to decrease the complication rates the animal should be placed on a heating pad. For hemodynamic stability NaCl should be administered subcutaneously. To reduce the risk of thrombosis, ice-cold saline containing heparin should be administered. Vascular complications, which mainly depend on the microsurgeon's expertise, can be prevented by meticulous surgical technique (preferably an end-in-end anastomosis). The main urinary complications can be minimized by avoiding stents and cannulas and focusing on using techniques like the bladder-patch technique.

Animal Husbandry↗
PubMed2005

[Surgical strategies for the prevention of gastrointestinal tumours].

Over many decades the surgical treatment of gastrointestinal tumours was limited to cases of manifest malignancy and was performed with curative or palliative intent. Molecular diagnostics have now led to an optimised characterisation of different sporadic and hereditary tumour entities. Furthermore, a number of diseases which are an obligatory precancerosis or which carry a very high risk of cancer in their long courses have now been identified. Parallel to these developments, a dramatic reduction of morbidity has been achieved in major abdominal surgery due to more subtle and blood-sparing surgical techniques and mortality has been reduced to a minimum even in the most major procedures. This combination nowadays safely allows preventive or preventive extended surgical measures in cases where interventional therapy cannot be adequately employed.

Adenomatous Polyposis Coli↗
PubMed2004

Hematogenous tumor cell dissemination during colonoscopy for colorectal cancer.

BACKGROUND: It has long been suspected that mechanical influences may enhance the release of viable colorectal cancer cells into the circulation. The objective of this study was to determine the extent of hematogenous tumor cell spread in colorectal cancer patients during colonoscopy. METHODS: Peripheral venous blood samples were taken before and after colonoscopy from 44 patients with colorectal cancer. Blood samples were examined using a reverse-transcriptase polymerase chain reaction assay to amplify cytokeratin 20 transcripts. RESULTS: Eleven patients with colorectal cancer displayed circulating tumor cells before and after colonoscopy (25%), whereas tumor cells were detected in six of 44 patients (14%) only after the procedure (p = 0.03, McNemar's test: tumor cell detection before after colonoscopy). All control samples consistently tested negative. CONCLUSIONS: Mechanical forces may result in enhanced release of viable colorectal cancer cells into the circulation; however, the clinical significance of these results needs to be clarified.

Adenocarcinoma↗
PubMed2004

[The transverse coloplasty pouch after low anterior resection: early postoperative results].

INTRODUCTION: A colon J pouch (CJP) still represents the standard rectal reservoir after low anterior resection. Though the CJP shows favourable early functional results, pouch evacuation problems tend to occur in the long term. The transverse coloplasty pouch (TCP), developed by our group allows comparable early functional results while avoiding evacuation problems. We report our experience with the TCP at the University Hospital of Heidelberg, Germany, and examine the risk of anastomotic leaks with this technique. METHODS: Between 1 October 2001 and 31 May 2003, 201 patients with rectal tumours underwent resection. Eighty-two patients with formation of TCP were enrolled in the study. RESULTS: During the creation of the TCP, no technical problems occurred, and the overall morbidity was 28%, including anastomotic leaks in seven patients (8.5%) and bleeding in two. The reoperation rate was 8.5%. An association between postoperative morbidity and preoperative radiation therapy could not be established. The hospital mortality rate was 3.6%. CONCLUSIONS: The use of TCP is a safe procedure which has gained worldwide acceptance in a short time, representing a technically straightforward procedure. Independently of patient size, habitus, and bulkiness of the colon, a TCP can always be performed after low rectal resection.

Adult↗