Complete shutdown of microvascular perfusion upon hepatic cryothermia is critically dependent on local tissue temperature

Since microvascular dysfunction with complete circulatory arrest and, thus, prolongation of tissue ischaemia is considered a potential mechanism for cell necrosis following hepatic cryosurgery, we determined the temperature necessary for induction of complete nutritive perfusion failure in cryothermia-treated rat livers. After localization of the cryoprobe with seven thermocouples and application of a single or double freeze-thaw cycle, in vivo fluorescence microscopy of the cryoinjured left lobe was performed over a 2-h period using a computer-controlled stepping motor, which guaranteed analysis of the identical liver tissue segments with exact allocation of the thermocouples and thus determination of tissue temperature. Cryothermia resulted in a central non-perfused part of injury, surrounded by a heterogeneously perfused peripheral zone. The non-perfused area after single and double freezing continuously increased over the first 90-min period due to a successive shutdown of perfusion within the peripheral border zone. Analysis of the thermocouples' temperature at the end of freezing revealed the 0 degrees C-front at 11.7 mm (single freeze-thaw cycle) and 12.1 mm (double freeze-thaw cycle) distant from the centre of the cryoprobe, which exactly corresponds with the initial (30 min) expansion of the area with nutritive perfusion failure. The increased non-perfused tissue area at 2 h conformed a critical border temperature between 8.29 +/- 1.63 degrees C and 9.07 +/- 0.24 degrees C. From these findings, we conclude that freezing of liver tissue to temperatures of at least < 0 degrees C causes complete/irreversible perfusion failure, which consequently will result in cell death and tissue necrosis, and may thus be supposed as a prerequisite for the safe and successful application of cryosurgery in hepatic tumour ablation.

Epi-illumination fluorescent light microscopy for the in vivo study of rat hepatic microvascular response to cryothermia

To elucidate the hepatic microvascular response to cryothermia, we studied the liver microcirculation of Sprague-Dawley rats after one and two 4-minute freeze-thaw cycles using intravital fluorescence microscopy. Irrespective of the number of freeze-thaw cycles applied, the nature of hepatic microvascular injury was characterized by complete stasis of sinusoidal blood flow within the central part of the cryolesions and heterogeneous sinusoidal perfusion in a critically perfused border zone located at the periphery of the lesions. Analysis over time (2 hours) revealed a successive shutdown of sinusoidal perfusion within this critically perfused border zone, which was caused by intravascularly lodging cell aggregates, blocking the lumen of individual sinusoids. The aggregates consisted of parenchymal cells and cell fragments, but did not include leukocytes or platelets. Strikingly, microvascular perfusion failure was associated with Ito cell disintegration and marked dilation of sinusoids (15.6 +/- 0.8 microm vs. 8.8 +/- 0.8 microm; P <.05). This excludes sinusoidal constriction as the cause of nutritive perfusion failure, and may indicate dysfunction of Ito cell-regulated vasomotor control by cryothermia. However, because circulating cell aggregates were frequently observed plugging individual microvessels, dilation of sinusoids may just be the result of passive distension caused by outflow blockade. Analysis of hepatic tissue at 8 weeks after cryothermia did not reveal regeneration and microvascular remodeling, but loss of hepatic tissue, which corresponded well with the tissue area presenting with sinusoidal perfusion failure during the initial observation period after cryothermia. The fact that there was no recovery of sinusoidal perfusion over the initial 2-hour observation period, but loss of tissue after 8 weeks, supports the view that cryothermia induces injury not only by direct low-temperature-mediated action, but also through ischemia caused by irreversible deterioration of the microcirculation.

Mixed agonistic-antagonistic cytokine response in whole blood from patients undergoing abdominal aortic aneurysm repair

OBJECTIVE

To characterize the impact of abdominal aortic aneurysm repair (AAAR) on spontaneous as well as lipopolysaccharide (LPS)-induced gene expression of pro- and anti-inflammatory cytokines.

DESIGN

Prospective, controlled in vivo/ex vivo study.

SETTING

University hospital.

PATIENTS AND INTERVENTIONS

Whole blood from 14 consecutive patients undergoing AAAR withdrawn prior to surgery (T1), at the end of ischemia (T2), 90 min after declamping (T3) and on the first postoperative day (T4) was cultured in the absence or presence of LPS. Five patients undergoing elective inguinal hernia repair served as controls.

MEASUREMENTS AND RESULTS

While tumor necrosis factor (TNF), Interleukin (IL)-1 and IL-10 plasma concentrations did not increase significantly, IL-6 was elevated at each time point, as compared with T1. Despite the spontaneous release of trace amounts of IL-6, the ability of cultured whole blood to mount a cytokine response in vitro to LPS was impaired for all cytokines studied at T2 (TNF-62%, IL-1-51%, IL-6 -20%, IL-10-51%). The stimulated IL-6 response was restored early after declamping (T3: +56 %) and enhanced 1 day after operation (T4: +144%). In contrast, stimulated TNF and IL-1 responses remained depressed at T3 (TNF -48%, IL-1-64%) and T4 (TNF-40%, IL-1-24%). A biphasic pattern was observed for IL-10 with initial depression at T3 (-51%) and restoration at T4 (+40%). Among the different cytokines monitored, only impaired TNF responsiveness at early reperfusion (T3) correlated with the postoperative course, as reflected by APACHE II. Cytokine response to LPS was maintained or even increased during and after surgery in the whole blood from patients undergoing hernia repair.

CONCLUSIONS

Despite consistent development of clinical signs of systemic inflammatory response syndrome (SIRS) and spontaneous release of IL-6 abdominal aortic aneurysm repair produces a state of impaired pro-inflammatory cytokine response upon a subsequent in vitro Gram-negative stimulus. This early impairment of TNF responsiveness seems to correlate with an unfavorable postoperative course.

[Cryosurgery--renaissance or real progress?]

The development and improvement of the cryosurgical technique in combination with intraoperative ultrasonographic imaging enables reliable destruction of liver tumors--although not free of complications--given that tried and tested rules of cryosurgical research are obeyed. In this respect, we can speak of real progress. On the basis of a 3-year testing phase with the CRYO6 cryosurgical apparatus from ERBE, a protocol for the cryosurgical technique for liver tumors is introduced. The spectrum of indications for cryosurgery includes the destruction of irresectable hepatic secondaries or primary tumors with curative intention and the freezing of insufficient or incomplete resection margins. The preliminary results of this treatment modality are encouraging. However, there remains a need for further clinical research to allow final judgement of the cryosurgical method.

[Symptomatic abdominal aortic aneurysm and left-sided infrarenal vena cava]

Coincidence of an abdominal aortic aneurysm and abnormalities of the inferior vena cava is a rare condition but has significance for surgical therapy. By the preoperative use of various imaging techniques and adapted surgical procedure the risk of the operation is decreasing to a minimal level. A case of symptomatic abdominal aneurysm and left-sided infrarenal vena cava is presented and the importance of preoperative examinations and operative strategy is discussed.

Decreased expression of CD44 splicing variants in advanced colorectal carcinomas

CD44v6 expression appears to be associated with adverse prognosis and propensity for metastasis in patients with colorectal cancer. However, expression of CD44 variants in different tumour stages has been poorly characterised. CD44 variant expression was investigated in normal colonic mucosa (n = 36), colorectal adenomas (n = 15), carcinomas (n = 62) and metastases (n = 6) by reverse transcriptase-polymerase chain reaction (RT-PCR) and Southern blotting with exon-specific probes. High frequencies of CD44 standard (CD44s) and CD44 epithelial (CD44e) were observed in normal and neoplastic tissue. CD44v2 was seen predominantly in adenomas (27%) and UICCI carcinomas (29%). CD44v5 expression was low in normal mucosa (3%), higher in adenomas and carcinomas (29-33%), independent of tumour stage. CD44v6 expression was low in normal mucosa (6%) and higher in adenomas (47%) and carcinomas (42%). Surprisingly, a significant decrease of CD44v6 was observed in metastatic primary tumours (8%) and metastases (17%) (UICCIV) (P < or = 0.05). Therefore, the concept of CD44v6 conferring metastatic potential to malignant cells cannot be supported by our data.

[Temperature distribution pattern in liver tissue in freezing procedures with new cryoprobes]

The performance of new cryoprobes was studied by measuring the spatial and temporal patterns of the temperature distribution in liver tissue around one to three active cryoprobes. After 15 min of maximal freezing a tissue region 22 mm in diameter was frozen to temperatures below - 50 degrees C by one active cryoprobe. With three cryoprobes, using the synergistic cooling effect, a tissue region 45 mm in diameter was cooled to temperatures below - 50 degrees C. Optimal placement of the cryoprobes was found to be of critical importance.

[Endosonography of the esophagus and mediastinum]

It was only the endoscopic ultrasonography that allowed the esophagus and posterior mediastinum to be accessible to ultrasonography. The esophageal wall may be presented in its different anatomic layers to a degree of precision unattained by any other imaging procedure. Being important in the esophagus, both the upper rim of the tumor and the infiltration depth can this way be prognosed correctly to about 85%. In consequence, this allows proceedings appropriate to the tumor stage within the bounds of a multimodal therapeutic concept of esophagus carcinomas. Impressions of the esophagus caused by mediastinal tumors are safely distinguished from intramural tumors. Multiple biopsies to get an examination specimen from a deeper layer should be performed under no other conditions than after endoscopic ultrasonographic examination and just for special questions. In the differential diagnosis of achalasia and peptic stenosis of the esophagus, endoscopic ultrasonography proved to be less efficient. As for bronchial carcinomas, conclusive hints may be drawn from transesophageal and intratracheal ultrasonography. However, due to limited possibilities of judgment caused by air-containing structures these methods are not firmly established in the preoperative staging.

Preoperative staging of rectal and colonic cancer

In rectal cancer, endosonography assesses the tumor penetration depth, EUS T1 to EUS T3, with a sensitivity of 96% and a specificity of 89%. The evaluation of lymph nodes is less accurate, at 79%. The surgical strategy is different in the three parts of the rectum, and depends on the endosonographic tumor stage: upper third of the rectum--anterior resection for all tumor stages; middle third of the rectum--EUS T1 N0: transanal endoscopic microsurgery for "low-risk" carcinomas; EUS T1-2: anterior resection; EUS T3: anterior resection with complete excision of the mesorectum, reconstruction with coloanal pouch; lower third of the rectum--EUS T1 N0: transanal endoscopic microsurgery for "low-risk" carcinomas; EUS T1-2: anterior or intersphincteric resection with complete excision of the mesorectum, reconstruction with colon pouch; EUS T3: abdominoperineal excision. With the impact of endosonography, the proportion of abdominoperineal excisions has dropped from 46% to 15% during the last five years. Laparoscopic technology is likely to have an increasing impact on surgical procedures that have previously required an open approach. The following treatment policy derived from the endosonographic staging of colon tumors is proposed: EUS T1, laparoscopic segmental resection; EUS T2, laparoscopic oncological resection; EUS T3, conventional open surgery.

Expression pattern of breast-cancer-associated protein pS2/BCEI in colorectal tumors

Recently, several carcinomas of the gastrointestinal tract were tested for pS2/BCEI activity, a gene isolated from breast-cancer cells and coding for a small secreted peptide. In the latter tumors, its activity is under estrogen control; surprisingly, it was also found expressed in carcinomas of the stomach, biliary tract and pancreas. We have now investigated the expression of this gene in 64 colorectal carcinomas, 31 adenomas and 13 polyps in comparison with their matrix tissues by applying molecular (RNA analysis) and immunohistochemical (pS2 antibody) techniques. Positive pS2 immunostaining (ranging from focal to strong immunoreaction) was noted in 89% of human colon cancers, while 11% remained negative. Furthermore, all 40 transitional mucosae were strongly positive, whereas normal mucosa was negative. Of hyperplastic polyps, 68.2% displayed a significant immunoreaction, and 80.6% of adenomas were focally positive. Finally, 6 out of 16 cases showed significant pS2 transcription in Northern blot analysis. These data clearly indicate that the breast-cancer-associated pS2 protein also plays an as yet undetermined role in the tumorigenesis of human colorectal carcinomas.

Role of endosonography in the surgical management of non-Hodgkin's lymphoma of the stomach

Ten patients with primary gastric non-Hodgkin's lymphoma (NHL) were preoperatively assessed by endoscopic ultrasonography (EUS). Tumor infiltration depth and lymph node involvement were assessed using the TNM classification system. EUS was 80% accurate in determining the TL stage and 90% in detecting lymph node metastases (NL stage). Based on the longitudinal tumor extent (antrum to fundus), as assessed by preoperative (n = 10) and additionally, intraoperative EUS (n = 3), partial gastric resection was performed in nine patients and total gastrectomy in one. All resection specimens had tumor-free resection margins (R0 resection rate 100%). These results were compared to those in 23 patients with gastric NHL operated on prior to the introduction of EUS in the hospital who were comparable with respect to tumor location and extent. In comparison with the ten cases where treatment was guided by EUS, the rate of total gastrectomy was higher (65% versus 10%) and the R0 resection rate lower (72% versus 100%) in this group of 23 patients. These results show that EUS may play a crucial role in the pre-surgical staging of gastric NHL.

[Monstrous Buschke-Loewenstein tumor (condylomata acuminata gigantea) with transition to invasive squamous epithelial cancer]

The case of a 34-year-old female is reported, who has suffered from recurring condylomata acuminata of the anogenital region since she was 16. In the further course of the disease multiple Buschke-Loewenstein tumors developed, and finally an invasively growing, highly differentiated, keratinizing squamous cell carcinoma. The course of the disease was complicated by severe septicemia. In the framework of multimodal therapy, laser resection was the preferred method of surgical intervention. A systemic or local interferon treatment has only a prophylactic character in this stage of the disease.

Endosonographic differentiation of mucosal and transmural nonspecific inflammatory bowel disease

Thirty-seven patients with nonspecific inflammatory bowel disease were examined with an ultrasonic colonoscope and the inflammation classified as mucosal or transmural. Mucosal inflammation was characterized by preservation of the five-layer structure of the wall with thickening of the submucosa. Transmural inflammation was endosonographically defined as sectional interruption or loss of the five-layer structure. In 14 of the 37 patients a colectomy was performed. Examination of 3 of the 14 resected specimens revealed inflammation confined to the mucosa. This was consistent in all three cases with the preoperative endosonographic evaluation. Eleven of the 14 resected specimens showed sectional transmural inflammation. Ultrasonographically all of the 11 patients fulfilled the criteria for transmural inflammation, whereas endoscopic and microscopic signs were consistent with transmural inflammation in 9 of the 11. Endosonography of the colon enables definition of mucosal inflammation thus providing criteria for selection of patient for ileoanal pouch construction.

Endoscopic ultrasonography of the mediastinum in the diagnosis of bronchial carcinoma

Thoracic computed tomography (CT) is an essential component in the preoperative staging of bronchial carcinomas as is mediastinoscopy (MSC) in cases of mediastinal lymphoma. It is known that endoscopic ultrasonography (EUS), as a new diagnostic procedure, can predict lymph-node involvement in cases of tumors in the upper gastrointestinal tract with an 80% probability. In a prospective study, we examined whether EUS could be used to ascertain the presence of mediastinal lymph nodes in cases of bronchial carcinoma. Since 1990, therefore, 32 patients with operable non-small-cell bronchial carcinoma have been examined with an Olympus-Aloka EU-M2 or EU-M3 (frequency 7.5 and 12 MHz) in addition to routine diagnostics. The graded cross-sections of lymph-node dissections obtained during subsequent surgery served as evidence as to the true or false prognosis of the lymph-node status. Endoscopic ultrasonography identifies the presence and estimates the size of subcarinal, tracheobronchial, paraortal and paraesophageal lymph nodes better than computed tomography. Lymph nodes lying behind organs containing air (pretracheal lymph nodes) cannot be identified by ultrasonography. Lymph-node involvement was correctly identified by EUS in 72% of the cases, and the specificity was 86%. The poor sensitivity, at 67%, is explained by the high proportion (37%) of patients with anthracosilicosis, as the latter produces the same echo pattern as malignant infiltration. In 47% of all the cases, CT showed enlarged mediastinal lymph nodes which were not actually infiltrated in 67%. Of these lymph nodes, 33% could be classified as definitely free of metastases on the strength of their echo pattern, the rest were inflamed or really infiltrated by metastases.(ABSTRACT TRUNCATED AT 250 WORDS)

[Limited surgical radicality in occult cancer of Vater's papilla]

Nine histologically proven benign adenomas of the papilla of Vater were consecutively treated by transduodenal full thickness excision and simultaneous staging of regional lymph nodes without severe postoperative complications. 4 patients had a small well differentiated (pT1 GIpN0) carcinoma, although there was neither macroscopically nor by frozen sections any suspicion of a malignant tumour. A more radical pancreatoduodenectomy was not carried out and the 4 patients are without tumour recurrence or metastases 1-8 years postoperatively.

Neoplasm to neoplasm metastasis. Pheochromocytoma harboring a metastasis of breast cancer

Breast cancer commonly metastasizes to the adrenal glands. Metastases to an already existing adrenal gland tumor, however, are a rare finding. To our knowledge, this report represents the first case of a breast carcinoma metastasizing to a pheochromocytoma. Metastases of a cancer to another coexisting tumor in the same individual is an unusual event.