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J R Siewert

Publications and source records attributed to J R Siewert.

At least 37 records · Page 2Linked to original sources
PubMed2005

[Abdomino-right-thoracic esophagectomy with intrathoracic anastomosis in Barrett's cancer].

The modified technique of abdomino-right-thoracic esophagectomy (the Lewis-Tanner approach) is increasingly being favoured as the surgical procedure of choice in patients with resectable adenocarcinoma of the distal esophagus, so-called Barrett's cancer. The technical details of this procedure and the reconstruction of gastrointestinal continuity using a gastric tube with high intrathoracic anastomosis are illustrated, as they have proved useful in our own practice during recent years.

Abdomen↗
PubMed2005

[Esophagectomy as therapeutic principle for squamous cell esophageal cancer].

The fatalistic approach towards surgical therapy of esophageal squamous cell cancer has been replaced in recent years by a more differentiated view. This was triggered by the establishment of individualized therapeutic modalities based on tumor stage, tumor location, general patient status, and comorbidity. Despite advances in nonsurgical therapy of squamous cell esophageal cancer, esophagectomy remains the central therapeutic modality. Primary subtotal en-bloc esophagectomy with lymphadenectomy is the only curative option with a high likelihood of success for resectable tumors (uT1-3 categories) located below the level of the tracheal bifurcation and for early more proximal tumors. In patients with locally advanced tumors at or above the level of the tracheal bifurcation, surgical resection can still cure those who respond to neoadjuvant radiochemotherapy. Preoperative "conditioning" of risk patients, surgical safety strategies in risk situations, and standardization of both the operative procedure and the perioperative management have resulted in a marked reduction of the previously substantial postoperative mortality to below 3% in experienced centers. In our own experience of 900 esophagectomies for squamous cell esophageal cancer, the 5-year survival rate rose from about 20% to more than 50% in the last two decades. Esophagectomy thus has become a safe operation and remains the only therapeutic option offering cure for a substantial proportion of patients with squamous cell cancer of the esophagus.

Adenocarcinoma↗
PubMed2005

[Prophylactic gastric surgery].

A premalignant condition with high risk of gastric cancer is the basis for prophylactic gastric surgery. The germline mutation carrier in the E-cadherin gene has a lifetime risk of 70-80% for diffuse-type gastric cancer, and high-grade intraepithelial neoplasia has a 60-70% gastric cancer risk. Other premalignant conditions such as HNPCC syndrome (5% gastric cancer) and low-grade intraepithelial neoplasia (10% risk) are moderate risk factors for developing gastric cancer. They do not justify prophylactic surgery, but surveillance is required. In case high-grade intraepithelial neoplasia or early gastric cancer is detected, an option is extended radicality with total gastrectomy instead of subtotal gastric resection. Positive family history and early-onset of gastric cancer are risk factors to consider when discussing prophylactic gastrectomy or extended radicality.

Adolescent↗
PubMed2005

Endocrine tumours of the hindgut.

Neuroendocrine tumours of the colon and rectum are rare but distinct with regard to clinical symptoms, diagnostic and therapeutic management and prognosis compared to other neuroendocrine tumours of the gut as well as ordinary colorectal cancer. Therapeutic algorithms are proposed depending mainly on analogous TNM categories and grading considering conventional and experimental surgical and non-surgical therapy. Colonic neuroendocrine tumours are often misdiagnosed as undifferentiated adenocarcinoma and are therefore not properly treated with adjuvant and additive chemotherapy. As most rectal neuroendocrine tumours are benign because of submucosal extension only, the size and infiltration depth correlates with lymph-node and distant metastases and therefore with the prognosis. It is unknown whether endoscopic ultrasound can improve the diagnostic accuracy compared to size-related conclusions, and therefore whether it can change therapeutic strategies and improve survival by modern rectal surgery.

Anastomosis, Surgical↗
PubMed2005

COX2 expression, angiogenesis, proliferation and survival in Barrett's cancer.

OBJECTIVES: To examine COX2 expression and its relation to angiogenesis, Ki67 and Bcl2 expression in Barrett's cancer. METHODS: Specimens from 48 R0-resected Barrett's adenocarcinoma were immunostained for cyclooxygenase 2 (COX2), CD 31 and alpha-sm actin to discriminate between mature and immature vessels, Mib-1 and Bcl2. COX2 staining, angiogenesis, Ki67 expression and Bcl2 expression were also measured. RESULTS: COX2 expression was increased in 25 of 48 cases. There was no significant correlation between COX2 expression and age, sex and tumor differentiation. A significant association was found between lymph node positive cases and elevated COX2 expression (p=0.008). The percentage of Ki67 positive cancer cells was 43.8% (range 15.4-67.5%) in the low COX2 group and 57.8% (range 12.0-84.6%) in the high COX2 group. The difference was statistically significant (p=0.046). The median neovascularisation coefficient in the low COX2 group was 11.68 (range 8.22-43.64) and 25.47 (range 8-38.3) in the high COX2 group. The difference was statistically significant (p=0.012). A significant difference in survival was observed between patients in the COX2 low category when compared with the COX2 high category (log-rank test p=0.013). CONCLUSIONS: Elevated COX2 expression is associated with lymph-node metastases and reduced survival in Barrett's cancer. This appears to be related to the induction of angiogenesis and proliferation.

Barrett Esophagus↗
PubMed2005

Influence of hospital volume on local recurrence and survival in a population sample of rectal cancer patients.

AIMS: To investigate the role of hospital volume and individual hospitals on long term outcomes (local recurrence and survival) of rectal cancer patients. METHODS: One thousand thirty-eight patients with rectal cancer were diagnosed between 1996 and 1998. From these, we analysed 884 patients with a resected invasive primary rectal cancer. Median follow-up was 5.7 years. The impact of hospital volume (<10, 10-30 and >30 rectal cancer patients annually) on local recurrence and survival was examined in a Cox model. Differences between the four largest clinics in the high volume group were also investigated. RESULTS: In the multivariate model predicting survival the following variables were significant: UICC stage, grade, age, local recurrence, and (neo-) adjuvant therapy treatment. In the multivariate model predicting local recurrence UICC stage, tumour localisation, and neoadjuvant therapy treatment were significant variables. Hospital volume was not a significant factor for survival or local recurrence. Within the high volume category one hospital showed significantly worse local recurrence rates than all other hospitals, but no survival difference could be seen between the four largest hospitals of the high volume group. CONCLUSIONS: This analysis of a rectal cancer population found that hospital volume did not determine survival or local recurrence. Detailed clinical data with long term follow-up from cancer registries are vital to demonstrate the quality of routine care.

Aged↗
PubMed2004

The value of endosonographic rectal carcinoma staging in routine diagnostics: a 10-year analysis.

BACKGROUND: Endosonography is currently the gold standard for the local staging of rectal carcinoma, but its accuracy varies from 62% to 91%. This study aimed to determine the accuracy of endosonography, to evaluate the interobserver variability, and to compare the performance of the 7.5-MHz and the 10-MHz ultrasound scanners. METHODS: Between 1990 and 2000, 458 patients with rectal cancer were included in the study. All the patients had undergone rectal endosonography with a 7.5-MHz scan (period 1: 1990-1996) or a 10-MHz scan (period 2: 1997-2000). Endosonographic staging was compared with pathologic staging. RESULTS: The overall rate for correctly classified patients was 69% with respect to the T category and 68% with respect to the N category. There was no difference between the two scanners. In terms of accuracy, the T3 category tumors were the most (86%) and the T4 tumors the least (36%) accurately classified. Overstaging of tumors (19%) was much more frequent than understaging (12%). A high interobserver variability of 61% to 77% was noted. For pT1 tumors, the 10-MHz scan was almost two times more accurate than the 7.5-MHz scan (71% vs 36%). CONCLUSIONS: The accuracy of endosonographic staging of rectal carcinoma very much depends on the T category. A high-resolution scanner and an experienced examiner can help to ensure that endosonography remains an important tool in the staging process of patients with rectal carcinoma, especially early carcinoma.

Carcinoma↗
PubMed2004

Enucleation of submucosal tumors of the esophagus: minimally invasive versus open approach.

BACKGROUND: Surgical enucleation of submucosal tumors (SMTs) of the esophagus (mostly leiomyomas) is indicated when either the tumors are symptomatic or their biological behavior is unclear. The classic approach is a thoracotomy, but tumor enucleation can now also be performed via thoracoscopy or, for distal tumors, via laparoscopy. METHODS: We assessed our experience with the different approaches in a total of 25 patients (n = 13 minimally invasive approach and n = 12 open surgery). Enucleation of the SMT was the basic surgical principle; the choice of the approach was based on the preference of the surgeon. RESULTS: Compared to open surgery, the minimally invasive approach reduced pulmonary complications, hospital stay, and postoperative wound-related pain. The operating time was the same for both approaches. CONCLUSION: Minimally invasive approaches are suitable for the surgical enucleation of submucosal esophageal tumors. Thoracoscopic and laparoscopic techniques are recommended as standard procedures in experienced centers.

Adolescent↗
PubMed2004

Periarterial application of papaverine during laparoscopic donor nephrectomy improves early graft function after kidney transplantation in pigs.

BACKGROUND: Laparoscopic donor nephrectomy (LDN) increases incentives to donation by subjects who might refuse an open operation. However, the incidence of delayed graft function is higher after LDN than after open operation. This may be caused by the reduction of renal perfusion as a result of the raised intraabdominal pressure and mechanically induced renal angiospasm during the operation. We conducted experiments to find out whether the application of papaverine around the renal artery during LDN could improve early graft function after transplantation. METHODS: Renal function was studied in 10 male pigs (weight approximately 25 kg). The left kidney was harvested laparoscopically (intraabdominal pressure 8 mmHg). Five animals were randomly selected to have perivascular application of 50 mg papaverine (treatment group) before preparation of the vessels. In controls no papaverine was used. After LDN and open right nephrectomy the left kidney was autotransplanted. The main outcome measures were volume of urine produced and creatinine clearance during the first 20 h after the transplant. RESULTS: The groups were comparable in respect of body weight, hemodynamic values, amount of infusions, warm and cold ischemia time, and duration of anastomosis. Urine output and creatinine clearance were significantly higher in pigs treated with papaverine than in controls. CONCLUSIONS: Papaverine substantially improved early graft function in pigs when applied around the renal artery during LDN. Whether this is applicable to procurement of human kidneys remains to be evaluated.

Animals↗
PubMed2004

Assessment of respiratory symptoms with dual pH monitoring in patients with gastro-oesophageal reflux disease.

BACKGROUND: Gastro-oesophageal reflux disease (GORD) is a commonly underestimated aetiological factor in patients with respiratory symptoms. In this study, acid reflux in healthy volunteers and patients with GORD with and without respiratory symptoms was investigated by dual pH monitoring. METHODS: Thirty healthy volunteers and 43 patients with GORD underwent oesophageal manometry and dual pH monitoring with one probe in the proximal and one in the distal oesophagus. Nineteen of the 43 patients complained of respiratory symptoms. RESULTS: There were no differences in proximal probe measurements between volunteers and patients without respiratory symptoms. Patients with GORD and respiratory symptoms had a higher prevalence of abnormally high exposure to gastric juice and more reflux episodes in the proximal oesophagus compared with patients with GORD and no respiratory symptoms. Some 17 of 19 patients with GORD and respiratory symptoms showed deteriorated oesophageal body motility. CONCLUSION: Dual pH monitoring is feasible and well tolerated, and provides an objective means of evaluating patients with GORD and respiratory symptoms. Prolonged exposure of the proximal oesophagus to gastric juice and disorders of oesophageal body motility seem to be responsible for the development of respiratory symptoms.

Adult↗
PubMed2004

Neoadjuvant therapy for oesophagogastric cancer.

BACKGROUND: The prognosis after surgery for oesophagogastric cancer remains poor. METHODS: This review clarifies current indications for neoadjuvant therapy for oesophageal and gastric cancer. A systematic literature research and evaluation of data from international cancer meetings were carried out. RESULTS: Recently published results of large randomized phase III trials underscore the potential value of neoadjuvant treatment for oesophagogastric cancer. However, it remains uncertain which subgroups of patients should routinely undergo preoperative therapy. Metabolic response evaluation during neoadjuvant treatment is a promising tool for the selection of responding patients. CONCLUSION: Neoadjuvant chemotherapy is a valid option for locally advanced oesophageal and gastric cancer. In the future, more effective and better tolerated treatment strategies, tailored to the specific tumour characteristics of each individual, should be possible.

Chemotherapy, Adjuvant↗
PubMed2004

Factors influencing survival after resection of pulmonary metastases from colorectal cancer.

BACKGROUND: Selection of patients for resection of lung metastases from colorectal cancer is problematic. The aim of this study was to evaluate clinically relevant prognostic factors and to define a subgroup of patients who would most benefit from such surgery. PATIENTS: Seventy-five patients (median age 58 (range 33-82) years) with pulmonary metastases from colorectal cancer underwent 104 R0 lung resections. Median follow-up was 33 (range 4-116) months. Patients who had no evidence of recurrent extrathoracic disease, no more than three metastases on either side, lobectomy as the maximal surgical procedure, and adequate cardiorespiratory function were eligible for surgery. Univariate and multivariate Cox regression, and classification and regression tree subgroup analyses were performed. RESULTS: Overall median survival was 33 months, with 3- and 5-year survival rates of 47 and 27 per cent respectively. Size of metastases (relative risk (RR) 2.6) and extent of resection (RR 0.4) were identified as independent prognostic factors. Primary tumour stage was significant in univariate analysis. Subgroup analysis defined two statistically relevant prognostic groups: patients with a maximum metastasis size of 3.75 cm or less with a disease-free interval of more than 10 months and patients with larger metastases and a shorter disease-free interval. Median survival and 5-year survival were 45 months and 39 per cent in the former group, and 24 months and less than 11 per cent in the latter. CONCLUSION: Subgroup analysis provided criteria for the selection of patients for R0 resection of lung metastases from colorectal cancer and differentiated between those at high or low risk of early tumour progression; the latter patients would benefit most from surgery.

Adult↗
PubMed2004

[Sentinel lymph node mapping in gastric and esophageal carcinomas].

During the last 5 years, the concept of sentinel lymph nodes has been investigated in a variety of solid tumors. Despite the multidirectional and complex lymphatic drainage of the stomach, early gastric cancer has been shown to be a suitable model for sentinel lymph node mapping. In contrast, sentinel lymph node mapping of esophageal cancer is compromised by the anatomic location of the esophagus and its lymphatic drainage in the closed space of the mediastinum. The technique and clinical application of sentinel lymph node mapping thus differ between esophageal and gastric cancer. Reliable detection of sentinel lymph nodes in the mediastinum requires radioisotope labelling, while blue dye and radioisotope labelling are both feasible for gastric cancer. In patients with early gastric cancer, laparoscopic resection with sentinel node negative status is already under investigation in clinical trials. In esophageal cancer, sentinel node mapping is still considered an experimental technique. Preliminary data, however, indicate that it may be reliable and feasible in patients with early adenocarcinoma of the distal esophagus.

Adenocarcinoma↗