Jens Hoeppner

Impact of different crystalloid volume regimes on intestinal anastomotic stability.

Background:Anastomotic insufficiency still remains an unsolved problem in digestive surgery. Little clinical data, regarding the impact of perioperative volume management exist, which suggest lower complication rates in intestinal surgery under restrictive volume regimens. The aim of our study was to investigate the effect of the extent of intraoperative fluid administration with crystalloids on the stability of intestinal anastomoses. Material and Methods:Twenty-one rats were randomly assigned to 3 experimental groups (n = 7 rats/group): control group CO (9 mL kg−1 h−1 crystalloid infusion), volume restriction group V (−) (3 mL kg−1 h−1), and animals with volume overload V (+) (36 mL kg−1 h−1). After midline incision, all animals received the corresponding infusion for a 30-minute period. Infusion was continued for further 30 minutes whereas an end-to-end small bowel anastomosis was performed 15 cm proximal to the Bauhin valve with 8 nonabsorbable interrupted inverting sutures. At reoperation on the 4th postoperative day, the anastomotic segment was dissected and the bursting pressure [mmHg] was measured. As a second parameter for the quality of anastomotic healing, hydroxyproline concentration was examined with a spectrophotometric method [&mgr;g/g dry tissue]. Histologically, structural changes of the anastomotic segments were assessed by 2 pathologists. Data are given as mean ± SEM. Results:Anastomotic insufficiency was not seen in all animals. Bursting pressure of CO animals was 102 ± 8 mmHg. Bursting pressure was lowest in V (+) with high volume exposure at 77 ± 6 mmHg and significantly lower than V (−) (112 ± 9 mmHg; P = 0.01) whereas the difference compared with the CO group did not reach significant values. Hydroxyproline concentration in V (+) (64.4 &mgr;g/g dry tissue ± 7.7) was significantly lower compared with V (−) (91.7 &mgr;g/g dry tissue ± 9.1) animals (P < 0.05). In all animals with volume overload a marked submucosal edema was found. Conclusion:We could demonstrate for the first time in a systematic investigation, that the quantity of crystalloid infusion, applied intraoperatively, has a significant impact on functional (bursting pressure) and structural (hydroxyproline) stability of intestinal anastomoses in the early postoperative period. Because the stability and quality of an intestinal anastomosis have an impact on insufficiency rates, it should be noted that volume overload may have deleterious effects on anastomotic healing and postoperative complications in digestive surgery, possibly because of a marked bowel wall edema.

Circulating tumor cells found in patients with localized and advanced pancreatic cancer

Objectives Isolation of circulating tumor cells (CTCs) holds the promise of diagnosing and molecular profiling cancers from a blood sample. Here, we test a simple new low-cost filtration device for CTC isolation in patients with pancreatic ductal adenocarcinoma (PDAC). Methods Peripheral blood samples drawn from healthy donors and PDAC patients were filtered using ScreenCell devices, designed to capture CTCs for cytologic and molecular analysis. Giemsa-stained specimens were evaluated by a pancreatic cytopathologist blinded to the histological diagnosis. Circulating tumor cell DNA was subjected to KRAS mutational analysis. Results Spiking experiments demonstrated a CTC capture efficiency as low as 2 cells/mL of blood. Circulating tumor cells were identified by either malignant cytology or presence of KRAS mutation in 73% of 11 patients (P = 0.001). Circulating tumor cells were identified in 3 of 4 patients with early (⩽American Joint Committee on Cancer stage IIB) and in 5 of 7 patients with advanced (≥ American Joint Committee on Cancer stage III) PDAC. No CTCs were detected in blood from 9 health donors. Conclusions Circulating tumor cells can be found in most patients with PDAC of any stage, whether localized, locally advanced, or metastatic. The ability to capture, cytologically identify, and genetically analyze CTCs suggests a possible tool for the diagnosis and characterization of genetic alterations of PDAC.

Intestinal-type of differentiation predicts favourable overall survival: confirmatory clinicopathological analysis of 198 periampullary adenocarcinomas of pancreatic, biliary, ampullary and duodenal origin

BackgroundPeriampullary adenocarcinomas comprise pancreatic, distal bile duct, ampullary and duodenal adenocarcinoma. The epithelia of these anatomical structures share a common embryologic origin from the foregut. With steadily increasing numbers of pancreatoduodenectomies over the last decades, pathologists, surgeons and oncologists are more often confronted with the diagnosis of “other than pancreatic” periampullary cancers. The intestinal subtype of ampullary cancer has been shown to correlate with better prognosis.MethodsHistological subtype and immunohistochemical staining pattern for CK7, CK20 and CDX2 were assessed for n = 198 cases of pancreatic ductal, distal bile duct, ampullary and duodenal adenocarcinoma with clinical follow-up. Routine pathological parameters were included in survival analysis performed with SPSS 20.ResultsIn univariate analysis, intestinal subtype was associated with better survival in ampullary, pancreatic ductal and duodenal adenocarcinoma. The intestinal type of pancreatic ductal adenocarcinoma was not associated with intraductal papillary mucinous neoplasm and could not be reliably diagnosed by immunohistochemical staining pattern alone. Intestinal differentiation and lymph node ratio, but not tumor location were independent predictors of survival when all significant predictor variables from univariate analysis (grade, TNM stage, presence of precursor lesions, surgical margin status, perineural, vascular and lymphatic vessel invasion, CK7 and CDX2 staining pattern) were included in a Cox proportional hazards model.ConclusionsIntestinal type differentiation and lymph node ratio but not tumor location are independent prognostic factors in pooled analysis of periampullary adenocarcinomas. We conclude that differentiation is more important than tumor location for prognostic stratification in periampullary adenocarcinomas.

Intraoperative crystalloid overload leads to substantial inflammatory infiltration of intestinal anastomoses—a histomorphological analysis

BACKGROUND It has been shown that crystalloid fluid-overload promotes anastomotic instability. As physiologic anastomotic healing requires the sequential infiltration of different cells, we hypothesized this to be altered by liberal fluid regimes and performed a histomorphological analysis. METHODS 36 Wistar rats were randomized into 4 groups (n=8-10 rats/group) and treated with either liberal (+) or restrictive (-) perioperative crystalline (Jonosteril = Cry) or colloidal fluid (Voluven = Col). Anastomotic samples were obtained on postoperative day 4, routinely stained and histophathologically reviewed. Anastomotic healing was assessed using a semiquantitative score, assessing inflammatory cells, anastomotic repair and collagenase activity. RESULTS Overall, the crystalloid overload group (Cry (+)) showed the worst healing score (P < 0.01). A substantial increase of lymphocytes and macrophages was found in this group compared to the other three (P < 0.01). Both groups that received colloidal fluid (Col (+) and Col (-)) as well as the group that received restricted crystalloid fluid resuscitation (Cry (-)) had better intestinal healing. Collagenase activity was significantly higher in the Cry (+) group. CONCLUSION Intraoperative infusion of high-volume crystalloid fluid leads to a pathological anastomotic inflammatory response with a marked infiltration of leukocytes and macrophages resulting in accelerated collagenolysis.

Limited resection for duodenal gastrointestinal stromal tumors: Surgical management and clinical outcome

AIM To analyze our experience in patients with duodenal gastrointestinal stromal tumors (GIST) and review the appropriate surgical approach. METHODS We retrospectively reviewed the medical records of all patients with duodenal GIST surgically treated at our medical institution between 2002 and 2011. Patient files, operative reports, radiological charts and pathology were analyzed. For surgical therapy open and laparoscopic wedge resections and segmental resections were performed for limited resection (LR). For extended resection pancreatoduodenectomy was performed. Age, gender, clinical symptoms of the tumor, anatomical localization, tumor size, mitotic count, type of resection resectional status, neoadjuvant therapy, adjuvant therapy, risk classification and follow-up details were investigated in this retrospective study. RESULTS Nine patients (5 males/4 females) with a median age of 58 years were surgically treated. The median follow-up period was 45 mo (range 6-111 mo). The initial symptom in 6 of 9 patients was gastrointestinal bleeding (67%). Tumors were found in all four parts of the duodenum, but were predominantly located in the first and second part of the duodenum with each 3 of 9 patients (33%). Two patients received neoadjuvant medical treatment with 400 mg imatinib per day for 12 wk before resection. In one patient, the GIST resection was done by pancreatoduodenectomy. The 8 LRs included a segmental resection of pars 4 of the duodenum, 5 wedge resections with primary closure and a wedge resection with luminal closure by Roux-Y duodeno-jejunostomy. One of these LRs was done minimally invasive; seven were done in open fashion. The median diameter of the tumors was 54 mm (14-110 mm). Using the Fletcher classification scheme, 3/9 (33%) tumors had high risk, 1/9 (11%) had intermediate risk, 4/9 (44%) had low risk, and 1/9 (11%) had very low risk for aggressive behaviour. Seven resections showed microscopically negative transsection margins (R0), two showed positive margins (R1). No patient developed local recurrence during follow-up. The one patient who underwent pancreatoduodenectomy died due to progressive disease with hepatic metastasis but without evidence of local recurrence. Another patient died in complete remission due to cardiac disease. Seven of the nine patients are alive disease-free. CONCLUSION In patients with duodenal GIST, limited surgical resection with microscopically negative margins, but also with microscopically positive margins, lead to very good local and systemic disease-free survival.

Selective inhibition of esophageal cancer cells by combination of HDAC inhibitors and Azacytidine

Esophageal cancers are highly aggressive tumors with poor prognosis despite some recent advances in surgical and radiochemotherapy treatment options. This study addressed the feasibility of drugs targeting epigenetic modifiers in esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EAC) cells. We tested inhibition of histone deacetylases (HDACs) by SAHA, MS-275, and FK228, inhibition of DNA methyltransferases by Azacytidine (AZA) and Decitabine (DAC), and the effect of combination treatment using both types of drugs. The drug targets, HDAC1/2/3 and DNMT1, were expressed in normal esophageal epithelium and tumor cells of ESCC or EAC tissue specimens, as well as in non-neoplastic esophageal epithelial (Het-1A), ESCC (OE21, Kyse-270, Kyse-410), and EAC (OE33, SK-GT-4) cell lines. In vitro, HDAC activity, histone acetylation, and p21 expression were similarly affected in non-neoplastic, ESCC, and EAC cell lines post inhibitor treatment. Combined MS-275/AZA treatment, however, selectively targeted esophageal cancer cell lines by inducing DNA damage, cell viability loss, and apoptosis, and by decreasing cell migration. Non-neoplastic Het-1A cells were protected against HDACi (MS-275)/AZA treatment. RNA transcriptome analyses post MS-275 and/or AZA treatment identified novel regulated candidate genes (up: BCL6, Hes2; down: FAIM, MLKL), which were specifically associated with the treatment responses of esophageal cancer cells. In summary, combined HDACi/AZA treatment is efficient and selective for the targeting of esophageal cancer cells, despite similar target expression of normal and esophageal cancer epithelium, in vitro and in human esophageal carcinomas. The precise mechanisms of action of treatment responses involve novel candidate genes regulated by HDACi/AZA in esophageal cancer cells. Together, targeting of epigenetic modifiers in esophageal cancers may represent a potential future therapeutic approach.

Multimodal Treatment of Locally Advanced Esophageal Adenocarcinoma: Which Regimen Should We Choose? Outcome Analysis of Perioperative Chemotherapy Versus Neoadjuvant Chemoradiation in 105 Patients

The study was done to compare treatment and long‐term outcomes of neoadjuvant chemoradiation (neoCRT) and perioperative chemotherapy (periCTX) in patients with surgically treated esophageal adenocarcinoma.

Pitfalls and Technical Aspects during the Research of Intestinal Anastomotic Healing in Rats

Background: Fundamental experimental research into intestinal anastomotic healing in rodent models will gain increasing interest in the future. Methods: The aim of this study was to describe our 5-year experience with a standardized experimental setup of small and large bowel anastomoses in a rodent model and present a basic set of assessment tools investigating anastomotic healing. Anastomotic technique, perioperative complications such as anastomotic insufficiency (AI) and obstructive ileus were in the focus. Results: During different studies with varying study patterns, 167 rat small bowel anastomoses and 120 colonic anastomoses were performed. Overall mortality was 3.6% in small bowel and 2.5% in colonic anastomoses, AI occurred in 2.9 and 4%, respectively. A postoperative obstructive ileus was seen in 3/167 small bowel anastomoses and none in the colonic group. Conclusion: When performing experimental intestinal anastomoses in a standardized operative setting and critically considering special perioperative issues, the incidence of relevant complications can be maintained at an adequately low level.

The pig as an experimental model for colonic healing study of leakage and ischemia in colonic anastomosis.

Background: The object of this experimental study was to develop a model of anastomotic failure due to primary leakage and ischemia in porcine large bowel anastomosis. Methods: End-to-end anastomosis was constructed at descending colon in 12 pigs. The pigs were randomly divided into three groups. In Group A, the anastomosis was applied with a leak of 18 mm. In Group B, in addition to primary leakage, an artificial ischemia of the proximal anastomotic bowel segment was created by ligation of supplying vessels over 5 cm. In Group C, an artificial ischemia was created in the same manner at the proximal and distal anastomotic segment and the anastomosis was applied with an intentional leakage as in Groups A and B. The animals were sacrificed immediately in case of clinical signs of anastomotic dehiscence, sepsis, peritonitis, or ileus. The animals were sacrificed on day 28. The peritoneal cavity was examined for peritonitis, anastomotic wound dehiscence, and pericolic abscess formation. Results: Distinct fibrinous coverings and adhesions at the anastomotic area were found in all animals. In cases of primary leakage without ischemia, only one of the four animals developed abscess at anastomotic side with clinical sepsis. In cases of primary leakage with ischemia of the proximal anastomotic bowel segment, one of the four animals presented generalized peritonitis with sepsis. In Group C, there were no signs of leakage or peritonitis, although three of the four animals developed colonic ileus due to obturation of the colonic lumen by a clot of necrotic bowel wall. Conclusion: Large anastomotic dehiscence and local ischemia of the bowel wall are not reliable factors for the development of intra-abdominal abscess, peritonitis, or sepsis in the pig model.

Impact of remote ischemic preconditioning on wound healing in small bowel anastomoses

AIM To investigate the influence of remote ischemic preconditioning (RIPC) on anastomotic integrity. METHODS Sixty male Wistar rats were randomized to six groups. The control group (n = 10) had an end-to-end ileal anastomosis without RIPC. The preconditioned groups (n = 34) varied in time of ischemia and time of reperfusion. One group received the amino acid L-arginine before constructing the anastomosis (n = 9). On postoperative day 4, the rats were re-laparotomized, and bursting pressure, hydroxyproline concentration, intra-abdominal adhesions, and a histological score concerning the mucosal ischemic injury were collected. The data are given as median (range). RESULTS On postoperative day 4, median bursting pressure was 124 mmHg (60-146 mmHg) in the control group. The experimental groups did not show a statistically significant difference (P > 0.05). Regarding the hydroxyproline concentration, we did not find any significant variation in the experimental groups. We detected significantly less mucosal injury in the RIPC groups. Furthermore, we assessed more extensive intra-abdominal adhesions in the preconditioned groups than in the control group. CONCLUSION RIPC directly before performing small bowel anastomosis does not affect anastomotic stability in the early period, as seen in ischemic preconditioning.