[Epidemiology and surgical treatment of pancreatic cancer in the State of Brandenburg : Analysis of 5418 cases]

BACKGROUND

Pancreatic cancer is the second most frequent cause of death among all forms of cancer in Germany with more than 19,000 deaths per year. The evaluation of the nationwide clinical cancer register aims to depict the reality of treatment and to improve the quality of treatment in the future by targeted analyses.

METHOD

The data from the clinical cancer register of Brandenburg-Berlin for the diagnosis years 2001-2017 were analyzed with respect to the treatment of pancreatic cancer. Data from patients resident in the State of Brandenburg were evaluated with respect to epidemiological and therapeutic parameters.

RESULTS

A total of 5418 patients with pancreatic cancer were documented in the register from 2001 to 2017 and 49.6% of the patients were diagnosed as having the Union for International Cancer Control (UICC) stage IV. A pancreas resection was carried out in 26.4% of the cases. In cases of cancer of the head of the pancreas the most frequent procedure was a pylorus-preserving resection with 51.8% and a pancreatectomy was carried out in 9.4%. The R0 resection rate of all pancreatic cancers in the period from 2014 to 2017 was 61.9%. After R0 resection the 5‑year survival was 19%. Relevant multivariate survival factors were age, UICC stage and the residual (R) tumor classification. The case numbers per hospital had no influence on the absolute survival of patients operated on in the State of Brandenburg.

CONCLUSION

The treatment reality in the State of Brandenburg for patients with pancreatic cancer corresponds to the results of international publications with respect to the key performance indicators investigated. A qualitative internationally comparable treatment of these patients is also possible in nonmetropolitan regions.

Outlier classification using autoencoders: Application for fluctuation driven flows in fusion plasmas

Understanding the statistics of fluctuation driven flows in the boundary layer of magnetically confined plasmas is desired to accurately model the lifetime of the vacuum vessel components. Mirror Langmuir probes (MLPs) are a novel diagnostic that uniquely allow us to sample the plasma parameters on a time scale shorter than the characteristic time scale of their fluctuations. Sudden large-amplitude fluctuations in the plasma degrade the precision and accuracy of the plasma parameters reported by MLPs for cases in which the probe bias range is of insufficient amplitude. While some data samples can readily be classified as valid and invalid, we find that such a classification may be ambiguous for up to 40% of data sampled for the plasma parameters and bias voltages considered in this study. In this contribution, we employ an autoencoder (AE) to learn a low-dimensional representation of valid data samples. By definition, the coordinates in this space are the features that mostly characterize valid data. Ambiguous data samples are classified in this space using standard classifiers for vectorial data. In this way, we avoid defining complicated threshold rules to identify outliers, which require strong assumptions and introduce biases in the analysis. By removing the outliers that are identified in the latent low-dimensional space of the AE, we find that the average conductive and convective radial heat fluxes are between approximately 5% and 15% lower as when removing outliers identified by threshold values. For contributions to the radial heat flux due to triple correlations, the difference is up to 40%.

[Metastasized colonic cancer. When are there no indications for primary resection?]

The determination of an optimal treatment protocol for colonic cancer with synchronous incurable metastases remains a challenge, especially if the primary tumor is asymptomatic. Available data on whether resection of the primary tumor means a benefit or a danger to the patient are limited and inhomogeneous. A survival benefit could be shown only in retrospective studies with a bias against primary chemotherapy. The important question of the quality of life (QOL) remains completely unanswered in this respect. There are numerous groups and guidelines in favor of a primary palliative chemotherapy for these patients, possibly intensified by antibodies. The results of the currently ongoing randomized multicenter SYNCHRONUS study will deliver objective data facilitating the decision-making process with respect to the indications for resection of the primary tumor or primary chemotherapy.

Laparoscopy in the surgical treatment of rectal cancer in Germany 2000-2009

AIM

The goal of this registry study was to compare open surgery with planned laparoscopy and then with laparoscopic to open conversion for rectal cancer surgery.

METHOD

The study included 17,964 rectal cancer patients, operated on between 1 January 2000 and 31 December 2009, from 345 hospitals in Germany. All statistical tests were two-sided, with the χ(2) test (Pearson correlation) for patients and tumour characteristics. Fisher's exact test was used for complications and 30-day mortality.

RESULTS

Of the 17,964 rectal cancer patients, 16,308 (90.8%) had an open procedure and 1656 (9.2%) were started with a laparoscopy. The 1455 patients with completed laparoscopic operations had fewer intra-operative and postoperative complications (5.4%vs 7.0%, P = 0.020, and 20.5%vs 25.8%, P < 0.001, respectively) and a lower 30-day mortality rate (1.1%vs 1.9%, P = 0.023). Of the 1656 planned laparoscopies, 201 (12.1%) were converted to open. The converted group suffered more intra-operative complications (18.9%vs 3.6% for completed laparoscopy and 7.0% for open surgery, P < 0.0001) and postoperative complications (32.3%vs 18.9% for completed laparoscopy and 25.8% for open operations, P < 0.0001). The converted group also had a higher 30-day mortality rate (2.0%vs 1.0% for completed laparoscopy and 1.9% for open surgery, P = 0.043).

CONCLUSION

The more favourable patient profile provided justification for a laparoscopic procedure. For those converted to an open procedure, however, there were significantly more complications than planned open surgery patients. A move away from the standard open procedure for rectal cancer surgery and towards laparoscopy is not yet feasible.

[The development process of colon cancer centres]

Colon carcinomas are the most common malignant tumours in the Western world. Important findings about the overall quality of medical care have been reported in multi-centre observational studies. A quality enhancement of therapeutic care can be achieved by an additional increase in diagnostic and therapeutic measures in the interdisciplinary setting. The development of colon cancer centres improves the chance to objectively observe the results of medical care induced by the development of an interdisciplinary and cross-sectoral unit that includes a comprehensive medical care for patients. The implementation of the current medical findings based on evidence in clinical routine, the inspection of the usage of guidelines by external specialists as part of an audit and the continuous correction of analysed deficits in the course of treatment guarantee a continuous improvement of service.

Incidence of synchronous liver metastases in patients with colorectal cancer in relationship to clinico-pathologic characteristics. Results of a German prospective multicentre observational study

BACKGROUND

The aim of this prospective observational multicentre study was to evaluate the incidence of synchronous liver metastases in colon and rectal cancer and to determine clinico-pathologic factors of the colorectal cancer that influenced the development of synchronous liver metastases.

METHODS

Of 48,894 patients with colorectal cancer and who underwent surgery between January 2000 and December 2004, 7209 developed hepatic metastases and were analyzed.

RESULTS

Synchronous liver metastases occurred in 14.7% of the colorectal cancer cases. Colon cancer (15.4%) led significantly more frequently to haematogenous spread to the liver than rectal cancer (13.5%) in a univariate approach. The N, V, and T stage, as well as the number of metastatic-involved local lymph nodes independently influenced the frequency of synchronous liver metastases in colon and rectal cancer in a multivariate analysis. Localization of the cancer in the colon led to a different number of synchronous liver metastases. Localization of the rectal cancer did not influence the rate of synchronous liver metastases. In the case of synchronous liver metastases, patients with colon cancer had significantly more peritoneal metastases (17.9 vs. 9.15%) but less lung (9.7 vs. 14%) and bone (0.7 vs. 1.6%) metastases. Simultaneous curative liver resections were done in 7% of colon cancer cases and in 8.8% of rectal cancer cases.

CONCLUSION

In this national study the incidence of synchronous liver metastases in colon and rectal cancer were different. Independent factors leading to synchronous liver metastases could be identified. Venous infiltration seems to be important for the development of distant metastases.

Low-volume centre vs high-volume: the role of a quality assurance programme in colon cancer surgery

AIM

The study aimed to determine whether hospitals within a quality assurance programme have outcomes of colon cancer surgery related to volume.

METHOD

Data were used from an observational study to determine whether outcomes of colon cancer surgery are related to hospital volume. Hospitals were divided into three groups (low, medium and high) based on annual caseload. Cancer staging, resected lymph nodes, perioperative complications and follow up were monitored. Between 2000 and 2004, 345 hospitals entered 31,261 patients into the study: 202 hospitals (group I) were classified as low volume (<30 operations; 7760 patients; 24.8%), 111 (group II) as medium volume (30-60; 14,008 patients; 44.8%) and 32 (groups III) as high volume (>60; 9493 patients; 30.4%).

RESULTS

High-volume centres treated more patients in UICC stages 0, I and IV, whereas low-volume centres treated more in stages II and III (P<0.001). There was no significant difference for intra-operative complications and anastomotic leakage. The difference in 30-day mortality between the low and high-volume groups was 0.8% (P=0.023).Local recurrence at 5 years was highest in the medium group. Overall survival was highest in the high-volume group; however, the difference was only significant between the medium and high-volume groups. For the low and high-volume groups, there was no significant difference in the 5-year overall survival rates.

CONCLUSION

A definitive statement on outcome differences between low-volume and high-volume centres participating in a quality assurance programme cannot be made because of the heterogeneity of results and levels of significance. Studies on volume-outcome effects should be regarded critically.

Quality assessment of colorectal cancer care: an international online model

AIM

We present an alternative approach to quality assessment in colorectal cancer, enabling a direct comparison of improvement at the level of the care provider.

METHOD

In 2000, a quality assessment project in colorectal cancer in Germany was started. Data were provided for every patient treated for colorectal cancer. The enrolment questionnaire described patient data, risk factors, reason for hospitalization, diagnostics prior to surgery, surgical procedures, intraoperative complications, general and surgical complications in postoperative period, pathological report and discharge status.

RESULTS

From 2000 to 2007, there were 57 429 patients included in the study. The total number of 372 hospitals that took part in the project varied from 153 to 281 per year. The overall resection rate for colon cancer was 97.1% and 94.8% for rectal cancer. Although the localization of rectal tumours did not vary, the percentage of abdominoperineal excisions fell from 26.1% in 2000 to 21.3% in 2008 (P < 0.001). Hospital mortality for colon cancer varied between 3.2% and 4.2% (P Pearson chi-square 0.032, linear-by-linear 0.257) and for rectal cancer between 2.7% and 3.7% (P Pearson chi-square 0.233). Patient age was not related to in-hospital mortality.

CONCLUSION

The proposed model of quality assessment shows validity and results comparable to population-based studies. It does not require support from the health care system, making its implementation possible in every hospital worldwide.

Colon carcinoma--classification into right and left sided cancer or according to colonic subsite?--Analysis of 29,568 patients

BACKGROUND

It is common to distinguish between right and left colon cancer (RCC and LCC). But, little is known about the influence of its exact location on the tumor stage and characteristics when considering the colonic subsite within the right or left colon.

METHODS

During a five-year period, 29,568 consecutive patients were evaluated by data from the German multi-centered observational study "Colon/Rectal Carcinoma". Patients were split into 7 groups, each group representing a colonic subsite. They were compared regarding demographic factors, tumor stage, metastatic spread and histopathological characteristics.

RESULTS

Analysis of tumor differentiation and histological subtype revealed a linear correlation to the ileocecal valve, supporting the right and left side classification model. However, cancers arising from the RCC's cecum (52.3%) and LCC's splenic flexure (51.0%) showed the highest proportion of UICC stage III/IV tumors and lymphatic invasion, whereas the RCC's ascending colon (46.5%) and LCC's descending (44.7%) showed the lowest, which supports a more complex classification system, breaking down the right and left sides into colonic subsites.

CONCLUSIONS

Age, tumor grade and histological subtype support the right and left side classification model. However, gender, UICC stage, metastatic spread, T and N status, and lymphatic invasion correlated with a specific colonic subsite, irrespective of the side. The classification of RCC or LCC provides a general understanding of the tumor, but identification of the colonic subsite provides additional prognostic information. This study shows that the standard right and left side classification model may be insufficient.

Primary appendiceal carcinoma--epidemiology, surgery and survival: results of a German multi-center study

BACKGROUND

While carcinoma of the colon is a common malignancy, primary carcinoma of the appendix is rare. Many retrospective reviews outlined experience from different centers on appendiceal neoplasms. However, the study population is often small because it is so rare. The aim of this study was to analyze the type of surgery and survival of patients with appendiceal malignancies using data from a German multi-center observational study (31 341 patients).

METHODS

During a five-year period, 196 consecutive patients with malignant appendiceal tumors were distributed into four groups: appendiceal carcinoids, adenocarcinoma, mucinous adenocarcinoma and adenosquamous carcinoma. The following parameters were analyzed: demographics, clinical presentation, comorbidities, type and appropriateness of surgery, final pathology and survival.

RESULTS

Adenocarcinoma had the highest incidence (50.5%). The most common presentation was that of acute appendicitis. Mean age at presentation was youngest for carcinoid tumors. Carcinoid tumors had lowest tumor size and localized disease was present in 72.9%. Metastatic spread at presentation was highest for adenosquamous and mucinous adenocarcinoma and each had a distinct pattern. Right hemicolectomy was performed in 71.4%, limited resection in 11.7%. Overall 5-year survival was 83.1% for carcinoid vs. 49.2% for non-carcinoid tumors. Histological subtype and tumor stage significantly affected survival.

CONCLUSIONS

Long-term outcome of carcinoid tumors is superior to non-carcinoid neoplasms. Among all appendiceal neoplasms, adenosquamous carcinoma is the rarest histological subtype which is most commonly associated with advanced tumor stage and worst prognosis. Appropriate oncologic resection is being performed in a significant percentage of cases in Germany. However, the high rate of right hemicolectomy in patients with small carcinoid tumors needs to be critically discussed.

Surgical practices for malignant left colonic obstruction in Germany

AIM

Data from the multicentric observation study Kolon/Rektum-Karzinome (Primärtumor) (primary colorectal carcinoma) are adduced to assess the status of surgical treatment of this condition in Germany and to compare different operative approaches in the emergency treatment of obstructive left-sided colon cancer, especially diversion (Hartmann's procedure) and primary anastomosis.

PATIENTS AND METHODS

Out of 15,911 patients with cancer of the left colon, recorded between 01.01.2000 and 31.12.2004, a total of 743 patients underwent emergency surgery for an obstructive tumour, performed as a radical resection. These patients were compared in respect of their risk profile and postoperative result.

RESULTS

In 57.9% (n=430) a one-stage operation (Group I), in 11.7% (n=87) a primary anastomosis with protective stoma (Group II), and in 30.4% (n=226), Hartmann's procedure (Group III) was performed. In Group III more patients were male, overweight and multimorbid, and more had advanced-stage tumours. The morbidity and hospital mortality (overall hospital mortality, 7.7%; n=57) did not differ significantly between the groups. The insertion of a protective stoma did not affect the rate of anastomotic insufficiency (Group I, 7%; Group II, 8.0%).

CONCLUSIONS

Primary anastomosis for emergency left colon carcinoma obstruction should only be regarded as indicated in cases where the risk profile is favourable. Our results suggest that in advanced obstruction and in high-risk cases Hartmann's procedure should be used. A protective stoma did not appear to confer any advantage.

[How safe is laparoscopic cholecystectomy?]

INTRODUCTION

Laparoscopic cholecystectomy (LCE) is the standard treatment for symptomatic non-complicated cholecystolithiasis. However, there is still an ongoing debate about the appropriate surgical approach in cases with complicated cholecystolithiasis. As a result, an initial decision whether to use the open or laparoscopic approach must be primarily based on patient safety. Additional indications favouring the use of LCE must not lead to an increase in the rate of serious complications.

METHODS

All patients who underwent operations for cholecystolithiasis performed in a single surgical centre, from 1 / 1 / 1994 to 12 / 31 / 2007, were considered in this analysis. Parameters for the characterisation of the results were intervention-associated hospital mortality and iatrogenic transsection of the common bile duct.

RESULTS

5 084 cholecystectomies were performed during the study period, 84 % (n = 4 272) intended as laparoscopic and 16 % (n = 812) as open procedures. The LCE operations were done by 36 surgeons. The conversion rate to open surgery was 6.2 % (n = 265), in cases of acute cholecystitis, however, it was 26.3 % (n = 86). One LCE procedure involved an iatrogenic bile duct transsection (0.02 %). The in-hospital mortality rate for LCE was 0.05 % (n = 2).

CONCLUSIONS

In the hands of experienced surgeons LCE is a safe procedure for the treatment of symptomatic, non-complicated cholecystolithiasis. Associated with complicated cholecystolithiasis however are an increase in conversion rate and thus the risk of severe complications.

[Surgical treatment of esophageal cancer]

Prospective study, included 117 patients with esophageal cancer, all received resection of the esophagus through laparatomy and and right-side thoracotomy without neoadjuvant chemotherapy. 70,0% of patients demonstrated stage higher then IIb UICC. R0 resection was possible in 101 patients (86,3%). Hospital lethality was 5,1%. Overall lethality among the operated patients was 21,4%. Long-term follow-up results were obtained in 96,6%. Surgical treatment alone does not provide satisfactory results for the patients with cancer of esophagus. Further therapy individualization and combination of surgery with modern neoadjuvant chemotherapy can provide better prognosis for these patients.

[Pseudomalignant primary renal actinomycosis after ureterosigmoidostomy. A case report]

Actinomycosis is a chronic infectious disease caused by a gram-positive anaerobe. The bacterial disease is known to predominantly affect the oropharyngeal mucosa and soft tissues as well as the gastrointestinal tract. However, renal involvement by actinomycosis is exceedingly rare. Thus, renal actinomycosis is usually diagnosed by means of histopathological assessment of nephrectomy specimens because affected patients seek medical care due to (peri-) renal mass lesion clinically mimicking cancer. To best of our knowledge, we present the first case worldwide reporting on a 65-year-old man diagnosed with renal actinomycosis following ureterosigmoidostomy in whom nephrectomy was performed due the clinical suspicion of renal cancer (stage cT4). Subsequently, calculated antibiotic therapeutic regimens were initiated after the diagnosis was suspected by the pathologist. During the entire postsurgical follow-up comprising a total of 6 months, the patient did not experience any local or systemic recurrence. In summary, detailed information concerning the etiology, the clinical symptoms as well as diagnostic and therapeutic options are discussed in our case report.

[Elective surgical treatment of a giant scrotal hernia]

We report on a 69-year-old man presenting with a giant scrotal hernia, who failed to tolerate a pre-operative pneumoperitoneum applied with the intention to increase his intra-abdominal capacity. After enlarging the hernial orifice, the hernia contents - comprising the entire small bowel, the right colon and the greater omentum - were replaced into the abdominal cavity. Closure of the abdominal wound with mesh support was possible only after extensive resection of the small bowel, together with the voluminous mesentery and greater omentum. In a second operation performed later on revision of the scrotum and penis was undertaken. It is not always possible to achieve the required increase in intra-abdominal capacity through the use of a pneumoperitoneum. In such cases, extensive bowel resections and the use of biomaterials for tension-free abdominal wall repair must form an integral part of the treatment concept. Surgical management of such giant hernias has to be adapted to the individual situation of the patient using all therapeutic options.

[Prospective multicenter comparative study of the management of peritonitis. Quality assurance in severe intra-abdominal infection]

Despite all the efforts made in the areas of intensive care and surgery, severe peritonitis remains a feared condition that is associated with a high mortality rate. Severe abdominal infections are accompanied by a high level of endotoxin production, resulting in the so-called systemic inflammatory response syndrome (SIRS), which is often complicated by multiple organ failure. In addition to the surgical elimination of the source of the infection, the removal of the endotoxin is of prime importance. The aim of surgical treatment of peritonitis is, in the first instance, the elimination of the bacterial contamination and prevention or reduction--if possible--of fibrin formation. Attempts to block the cascade of mediators by pharmacological means have so far proved ineffective. For more than 10 years, therefor, various forms of abdominal lavage have been of vital importance in reducing bacterial contamination and aiding the healing process after successful surgical elimination of the focus of infection. A watertight temporary closure for the abdominal wall (TAC) was developed, which makes possible the continuous irrigation of the abdominal cavity. At the same time, it also gives the oedematous abdominal organs room to expand without the constraints otherwise imposed by the abdominal wall. This concept has extended the spectrum of surgical options, and we believe that, as a result, a reduction in the mortality rate associated with severe peritonitis with sepsis (MPI > 26) can be achieved. To investigate this hypothesis, a multi-centre study is presently being conducted. In a prospective parallel-group study, patients are randomized to either programmed etappenlavage with the Ethizip or to open dorsoventral interval therapy using the TAC. The patients are stratified on the basis of APACHE II and MPI, and the post-operative course is documented in a standardized manner. As secondary objectives, the study also aims to clarify the question as to whether the new therapeutic concept is also capable of reducing the number of revisions necessary, the duration of intensive care treatment, and the lenght of hospitalization, as also of abbreviating antibiotic treatment. Since it is being done under controlled conditions, and a uniform documentation is being used, the study represents a major contribution to quality control in the field of surgical treatment of peritonitis.

[Laparoscopic creation of stomas--an ideal single indication in minimally invasive surgery]

The laparoscopic creation of ileostomas and colostomas can be performed in a quick, safe and technically effective manner. The advantages of the minimally invasive approach are low morbidity and mortality, minimal blood loss and fast recovery in these mostly multimorbid patients as well as shorter time of hospitalization. We report on a total of 20 patients who underwent laparoscopic creation of colostoma in 19 cases and creation of ileostoma in one case in a period of 2 years. There were no intraabdominal complications and no lethal outcome. All patients reached their preoperative level of mobilization at the 2nd postoperative day. The indications for the laparoscopic enterostomy are described.

[Postoperative recurrent nerve paralysis after initial interventions for benign goiter]

Between January 1st, 1979 and December 31st 1993, 2501 operations for benign diseases of the thyroid gland were performed. The documentation was done prospectively. The operation technique remained the same during these years. The recurrent laryngeal nerve wasn't routinely identified. All together we saw 0.6% permanent vocal cord palsies. The incidence of nerve paralysis was correlated to the size (weight), to the expansion of the goiter, to the performed operative procedure and to patients' age and gender.

[Abdomino-thoracoscopic esophagus resection--an animal experiment study]

Based on animal trials the presented study results describe a method of abdomino-thoracoscopic oesophagectomy for the treatment of oesophageal carcinoma of the middle and lower third. Technical details and the advantages of the surgical procedure, including the avoidance of thoracotomy and the practicability of the thoracoscopic dissection of the oesophagus are shown. Problems exist in the salvage of the specimen, especially in the transcervical passage of the tumorbearing oesophageal part. A final evaluation of the importance of the minimally invasive techniques in oesophageal surgery should not be given until the results of clinical studies are available.