C. Kuntz

General stress response to conventional and laparoscopic cholecystectomy.

ObjectiveIn many retrospective and prospective observational studies, laparoscopic cholecystectomy (LC) compares favorably with conventional cholecystectomy (CC), with respect to length of hospital stay, postoperative pain, and pulmonary function, indicating a diminished operative trauma. Comparison of laboratory findings (stress hormones, blood glucose, interleukins) are a possibility to objectify stress and tissue trauma of laparoscopic and conventional cholecystectomy. Summary Background DataMajor body injury, surgical or accidental, evokes reproducible hormonal and immunologic responses. The magnitude of many of these changes essentially is proportional to the extent of the injury. MethodsIn a prospective study, biochemical stress parameters were measured in the blood of patients undergoing elective cholecystectomy because of symptomatic cholecystolithiasis. Patients with acute cholecystitis, pancreatitis, choledocholithiasis, or malignant disease were excluded. Values from 40 patients after LC and from 18 patients after CC were compared. Both groups had similar patient characteristics, baseline values, and perioperative care, except for deeper anesthesia during CC. ResultsOn postoperative day 1, epinephrine (p = 0.05), norepinephrine (p = 0.02), and glucose (p = 0.02) responses were higher after CC. Two days postoperatively, norepinephrine remained higher after CC (p < 0.01). Interleukin-1β responses were higher during (p < 0.01) and 6 hours after CC (p = 0.03). Interleukin-6 responses were higher 6 hours (p = 0.03), 1 day (p = 0.02), and 2 days (p < 0.01) after CC. ConclusionsThe results show significant lower values of intraoperatively and postoperatively measured epinephrine, norepinephrine, interleukin-1β, and interleukin-6 in patients with laparoscopic cholecystectomy, indicating a minor stress response and tissue trauma in this group of patients. The results correspond to the favorable results of most other trials evaluating clinical aspects of laparoscopic cholecystectomy.

Effect of pressure and gas type on intraabdominal, subcutaneous, and blood pH in laparoscopy

AbstractBackground: According to the literature, the number of port-site metastases in laparoscopic surgery varies considerably depending on the type of gas used for the pneumoperitoneum. In order to investigate this observation we studied the changes in blood, subcutaneous, and intra-abdominal pH during laparoscopy with helium, CO2 and room air in a rat model. In addition, we looked at the influence of intra-abdominal pressure and duration of pneumoperitoneum on the pH during the laparoscopy. Methods: pH was measured by tonometry, intra-abdominally and subcutaneously. A pH electrode was additionally placed into the subcutaneous tissue and the results compared to those measured by tonometry. Blood samples were taken from a catheter in the carotid artery. The intra-abdominal pressure was 0, 3, 6, 9 mmHg for 30 min in each case. We investigated the effect of pneumoperitoneum with CO2, helium and air in randomized groups of 5 rats. In an additional series the pressure was held constant at 3 mmHg and the pH was measured every 30 min. Results: Due to the different absorption capacity of the peritoneum, laparoscopy with CO2 decreases the subcutaneous pH from 7.35 to 6.81. Blood pH is reduced from 7.37 to 7.17 and the intra-abdominal pH from 7.35 to 6.24. Other, less absorbable gases induce smaller changes of blood and subcutaneous pH (only 10% of CO2). In a variance analysis the p value is less than 0.001. The influence of duration of laparoscopy (30 min vs 90 min) on the subcutaneous pH is less compared to the influence of intra-abdominal pressure (0, 3, 6, 9 mmHg). Conclusions: Depending on the type of gas (CO2, air, helium) used for laparoscopy blood, subcutaneous and intra-abdominal pH are influenced differently. Because lower pH is known to impair local defense mechanisms, these results may be one explanation for the higher incidence of port-site metastasis in laparoscopy with CO2 than with other gases, as reported in the literature.

Prospective Comparison of Endoscopy, Endosonography and Computed Tomography for Staging of Tumours of the Oesophagus and Gastric Cardia

Background: Local and multimodal therapeutic strategies for tumours of the oesophagus and gastric cardia, require precise preoperative staging. Endosonography is considered the most accurate staging method, while computed tomography (CT) has limitations especially in the evaluation of local infiltration. Macroscopic endoscopic evaluation was reported to be accurate in selected series, but no study has yet compared all three staging modalities. Methods: One hundred and seventeen unselected patients with tumours of the oesophagus and gastric cardia were prospectively staged first by the endoscopic macroscopic appearance and then by endosonography. All patients had preoperative CT scans, however, only the 36 patients receiving the scans at our institution were included in the study. The preoperative staging results were then compared to postoperative histology which was available as the gold standard in all included patients. Kappa statistics were used to exclude chance agreement of the clinical staging results with the pathohistological findings. Differences between the resulting ĸ values for the different staging modalities were analysed with a jack-knife test. Results: Endoscopic macroscopic staging and endosonography (accuracy 67 and 69%, weighted ĸ 0.78 and 0.84) were significantly more accurate than CT (accuracy 33%, weighted ĸ 0.44) for determination of the T category (p = 0.006 and p = 0.001). After exclusion of tumours of the cardia (n = 33), the accuracy of macroscopic and endosonographic staging (accuracy 72 and 75%, weighted ĸ 0.86 and 0.88) increased and remained more accurate than CT (accuracy 50%, weighted ĸ 0.62). The main pitfall in our series in staging the T category was the overestimation of T2 tumours in the cardia as T3 or even as T4 tumours due to the inability to visualise the serosa. The accuracy of predicting lymph node metastasis was 68% for macroscopic endoscopic, 79% for endosonographic, and 67% for CT staging. Only endosonographic staging was significantly different from chance agreement with histology (weighted ĸ = 0.56). Endosonographic staging was significantly more accurate than endoscopic macroscopic and CT staging (p = 0.03). Conclusions: Endosonography is the most accurate staging modality for overall preoperative staging of oesophageal and cardial tumours. Endoscopic macroscopic staging allows a reasonably accurate assessment of the T category.

Prospective randomized study of stress and immune response after laparoscopic vs conventional colonic resection

AbstractMethods: In order to evaluate the stress and immunological response to laparoscopic and conventional colon resection we operated on male Wistar rats (350–380 g), performing either laparoscopic (n= 15) or open colon resection (n= 15). A third group (n= 10) underwent anesthesia only. Immediately before and after surgery as well as 1 and 7 days postoperatively a 1 ml sample of blood was taken from the retrobulbar veinous plexus. Stress (corticosterone) and immune parameters (neopterin and interleukin [IL] 1-β) were measured. Furthermore, the body weight as a parameter of postoperative recovery was monitored. Results: The analysis of variance showed significant differences between the three groups over a period of 1 week (p < 0.0001 for corticosterone, p= 0.0854 for IL 1-β, p= 0.0045 for neopterin). Additionally in a t-test significant differences were found between the laparoscopic and conventional group with regard to corticosterone (p= 0.08), to neopterin (p= 0.045), and to IL 1-β (p= 0.0043) at the end of the operation.One week after the operation the stress and immune parameters were back to normal levels in each group except IL 1-β, but the recovery indicated by body weight was different according to the kind of the applied operative procedure: 7 days postoperatively the rats lost 5.99% of their body weight after open surgery and only 2.4% after laparoscopic surgery. After anesthesia only the body weight increased by about 4.8%. Conclusion: Laparoscopic colon resection alters the stress and immune system of healthy rats less than open colon resection. This observation is confirmed by the quicker recovery in laparoscopically operated rats.

Endorectal ultrasound for control of preoperative radiotherapy of rectal cancer

Endorectal ultrasound (EDS) is known to be a reliable method for preoperative staging of rectal tumors. In this study, EUS was used to select patients with rectal cancer suitable for preoperative radiation therapy. By performing EUS before and after radiation, the aim of the study was to evaluate the role of EUS in monitoring the effects of preoperative radiation therapy. In 17 patients with large T3 or T4 rectal tumors, a complete staging by EUS was done before and after radiation therapy. Beside a shrinkage of the tumor, there was a change of echopattern to more hyperechoic gray levels to be observed in the irradiated tumor. The rectal wall lost its normal architecture, and lymph nodes disappeared or changed their echopattern from echopoor to echorich. There was no down-staging of a tumor seen by EUS. Complete preoperative staging was correct in 13 of 17 patients because of endosonographic examination before and after preoperative radiation therapy. New interpretation criteria are given for evaluation of patients with rectal cancer treated by radiation therapy.

Imaging diagnosis for staging of gastric cancer

A more differentiated therapy regimen concept for gastric cancer requires more precise pre-operative diagnostic imaging. There are several methods for pre-operative locoregional tumor staging in gastric cancer: percutaneous abdominal ultrasound with hydrotechnique (HUS), endoluminal ultrasound in the stomach (EUS), computed tomography (CT), and magnetic resonance imaging (MRI). The advantages and indications for each method are described and an overview of the medical literature is given. The results in the literature are compared to our own findings, which were obtained in prospective studies comparing the four different imaging methods. On the basis of our experience and the literature, we conclude that the indication for the different diagnostic imaging methods primarily depends on the type of therapy concept followed in the respective surgical department. Endoscopy with biopsy remains the primary diagnostic procedure. Endosonography (EUS) is another diagnostic procedure, which can be performed simultaneously with endoscopy. Only special questions or reasons warrant the use of other imaging methods.

New coil concept for endoluminal MR imaging

Our aim was to conduct a prospective study to evaluate staging accuracy of a new coil concept for endoluminal magnetic resonance imaging (MRI) on ex vivo gastric carcinomas. Twenty-eight consecutive patients referred to surgery with a clinically proven primary gastric malignancy were included. Surgical specimens were examined with a foldable and self-expanding loop coil (8-cm diameter) at 1.5 Tesla immediately after total gastrectomy. T1- and T2-weighted and opposed-phase sequences (axial, frontal sections; 3- to 4-mm slice thickness) were acquired. Investigators blinded to any patient information analyzed signal intensity of normal gastric wall, gastric tumor, and lymph nodes. Findings were compared with histopathological staging. On surgical specimens, 2–5 gastric wall layers could be visualized. All gastric tumors (26 carcinomas, two lymphomas) were identified on endoluminal MR data (100%). Overall accuracy for T staging was 75% (18/24); sensitivity to detect serosal involvement was 80% and specificity 89%. N staging correlated in 58% (14/24) with histopathology (N+ versus N−). The endoluminal coil concept is feasible and applicable for an ex vivo setting. Endoluminal MR data provided sufficient detail for gastric wall layer differentiation, and therefore, identification of T stages in gastric carcinoma is possible. Further investigations in in vivo settings should explore the potential of our coil concept for endoluminal MR imaging.

Metabolism and immunology in laparoscopy: First workshop on experimental laparoscopic surgery, Frankfurt, 1997

Surgery has been shown to result in a physiologic stress response and postoperative immunosuppression. The human and animal organisms answer to such an injury is characterized by an early rise of the serum level for stress hormones and a drop in the immunoresponse conveyed by the cells. This causes a reduction in lymphocyte and macrophage interactions; a decreased activity of natural killer cell, lymphocyte, and neutrophil chemotaxis; and delayedtype hypersensitivity (DTH) responses. The force and duration of the stress reaction is considered to be proportional to the severity of the injury. There is a correlation between a reduced perioperative cell-conveyed immunoresponse and an increased risk of postoperative infection and metastatic tumor spreading [12, 14, 15, 16, 18, 21]. Laparoscopic surgery is associated with less postoperative pain and earlier return to normal activity than conventional surgery. Furthermore, immune function of the patient may be better preserved using the laparoscopic approach [10, 17]. Nevertheless, further experimental studies about metabolism and immunology are necessary to support suggested advantages. The rat has been used extensively in studies of immunity and cancer is increasingly used for laparoscopic research [2, 3, 7, 8]. Surgery alters the stress and immune system of healthy rats. To evaluate the stress and immunologic response of laparoscopic and open surgery Kuntz [13] performed laparoscopy-assisted and conventional colon resection in rats. Immediately before and after surgery as well as 1 and 7 days postoperatively serum levels of corticosterone, neoptrine, and IL 1-13 were measured. At the end of the operation, significant differences were found between the laparoscopic and conventional groups with regard to corticosterone, neopterine, and IL 1-13. One week after the operation, the stress and immune parameters were back to normal levels in all except the IL 1-13 group, but the recovery indicated by body weight was different according to the kind of applied procedure. Seven days after open surgery, the body weight was significant lower than after laparoscopic surgery. The body weight supposedly reflects anabolic state. Another representative parameter of anabolism is insulin-like growth factor I (IGF-I), an analog of insulin. IGF is important for normal human growth and development and

Comparison of laparoscopic versus conventional technique in colonic and liver resection in a tumor-bearing small animal model

Background: Laparoscopic procedures in oncological surgery are either done in curative or palliative intent. We present two experiments comparing laparoscopic to conventional surgery in the curative and palliative setting regarding short-term (stress and immune alteration) and long-term aspects (survival time and recurrence rate). Methods: We established two syngenic tumor-bearing small animal models for curative liver resection (Morris hepatoma 3924A, ACI rats) and palliative colon resection (BSp73 ASML, BOX rats). Male rats were operated on, performing laparoscopic and conventional liver resection as well as laparoscopic and conventional colon resection; control groups (anesthesia) were included. The following parameters of the stress and immune system were measured: corticosterone, neopterine, Il-1-b, Il-6, and body weight as a parameter of postoperative recovery. Analyzed long-term parameters were survival time, tumor weight, and recurrence rate (histology). Results: After colon resection, analysis of variance showed significant differences in all short-term parameters, including body weight after laparoscopic versus conventional colon resection (p <0.05). In the case of laparoscopic versus conventional liver resection, only Il-6 showed globally statistically significant differences for the short-term parameters (p = 0.05). Long-term parameters were not significantly different between the laparoscopic and conventional groups, regardless of the type of resection (colon or liver) or the operative setting (curative or palliative). However, there were differences after curative liver resection compared to the control group (anesthesia alone). Conclusion: These results suggest that the type of intraabdominal operation (colon or liver) may influence the degree of trauma of an operation more than the type of technique (laparoscopic or open). The perioperative alteration of stress and immune function has no implications on the long-term results, such as survival time or recurrence, neither in the curative nor in the palliative setting. The thesis that laparoscopic surgery results in less pain, which in turn means less stress and less alteration of the immune system and therefore results in a lower rate of postoperative metastasis is only valid for laparoscopic colonic resection in our model. The part of the thesis that states that fewer metastases should occur after laparoscopic oncological surgery cannot be confirmed in our study.

TNM staging of gastrointestinal tumors by hydrosonography: results of a histopathologically controlled study in 60 patients

Abstract.Background: The study is a prospective evaluation of preoperative TNM staging of gastrointestinal tumors by hydrosonography (HUS). Methods: Sixty patients with suspected gastric or colorectal cancer underwent HUS for TNM staging. All patients were operated on and the tumors completely removed when possible. HUS findings were correlated with histopathologic staging. Results: HUS correctly localized tumors in 75% of patients. T stage accuracy was low for gastric cancers (41%). N staging of gastric cancers was accurate in 68% of all cases and was highly specific (100%). Staging was more accurate for colorectal tumors (70%), especially with respect to infiltration of other structures (sensitivity 100%, specificity 95%). N staging, however, was not reliable, mostly owing to impaired examination conditions. Conclusion: HUS easily misses tumors of the gastric cardia and distal part of the rectum. T staging of colorectal tumors with HUS is highly accurate, reaching 92% if the tumor is localized. T1 cancers of the stomach tend to be overstaged, and serosal infiltration by gastric cancers is often misjudged. With the exception of cardial gastric and distal rectal cancers, HUS comes close to endosonography for staging gastrointestinal tumors. HUS does not require intraluminal access.