Evaluation of a quality improvement intervention to reduce anastomotic leak following right colectomy (EAGLE): pragmatic, batched stepped-wedge, cluster-randomized trial in 64 countries

BACKGROUND

Anastomotic leak affects 8 per cent of patients after right colectomy with a 10-fold increased risk of postoperative death. The EAGLE study aimed to develop and test whether an international, standardized quality improvement intervention could reduce anastomotic leaks.

METHODS

The internationally intended protocol, iteratively co-developed by a multistage Delphi process, comprised an online educational module introducing risk stratification, an intraoperative checklist, and harmonized surgical techniques. Clusters (hospital teams) were randomized to one of three arms with varied sequences of intervention/data collection by a derived stepped-wedge batch design (at least 18 hospital teams per batch). Patients were blinded to the study allocation. Low- and middle-income country enrolment was encouraged. The primary outcome (assessed by intention to treat) was anastomotic leak rate, and subgroup analyses by module completion (at least 80 per cent of surgeons, high engagement; less than 50 per cent, low engagement) were preplanned.

RESULTS

A total 355 hospital teams registered, with 332 from 64 countries (39.2 per cent low and middle income) included in the final analysis. The online modules were completed by half of the surgeons (2143 of 4411). The primary analysis included 3039 of the 3268 patients recruited (206 patients had no anastomosis and 23 were lost to follow-up), with anastomotic leaks arising before and after the intervention in 10.1 and 9.6 per cent respectively (adjusted OR 0.87, 95 per cent c.i. 0.59 to 1.30; P = 0.498). The proportion of surgeons completing the educational modules was an influence: the leak rate decreased from 12.2 per cent (61 of 500) before intervention to 5.1 per cent (24 of 473) after intervention in high-engagement centres (adjusted OR 0.36, 0.20 to 0.64; P < 0.001), but this was not observed in low-engagement hospitals (8.3 per cent (59 of 714) and 13.8 per cent (61 of 443) respectively; adjusted OR 2.09, 1.31 to 3.31).

CONCLUSION

Completion of globally available digital training by engaged teams can alter anastomotic leak rates. Registration number: NCT04270721 (http://www.clinicaltrials.gov).

Anastomotic Leakage after Gastrectomy for Gastric Cancer

Anastomotic leakage (AL) constitutes a prominent cause of significant morbidity following gastrectomy for gastric cancer. The manifestation of AL typically occurs within 7 to 10 days post-surgery, with reported incidence rates of 5.8-6.7% for open gastrectomy and 3.3-4.1% for laparoscopic gastrectomy. Various predisposing risk factors have been identified, including the individual nutritional status (excluding obesity) and preoperative corticotherapy. Interestingly, the administration of neoadjuvant therapies appears to reduce the AL occurrence. In the context of distal gastrectomies, the rates of AL are comparable between laparoscopic, robotic, and open approaches. The total gastrectomies have higher AL rate compared to distal gastrectomies, which are considered the preferred approach. Prophylactic drainage measures have not demonstrated efficacy in preventing AL. As for postoperative management, conservative treatment is indicated for patients presenting with mild clinical symptoms and increased inflammatory blood tests. This approach involves fasting, enteral or parenteral nutrition, administration of antibiotics, and percutaneous drainage. For small AL, endoscopic therapies such as stents, vacuum therapy, clips, suturing devices, and injections are appropriate treatment options. In cases of high-volume fistulas, severe sepsis or failure of previous therapies, surgical reoperation becomes the ultimate solution.

Non-invasive laparoscopic detection of small tumors of the digestive tract using inductive sensors of proximity

The precise location of gastric and colorectal tumors is of paramount importance for the oncological surgeon as it dictates the limits of resection and the extent of lymphadenectomy. However, this task proves sometimes to be very challenging, especially in the laparoscopic setting when the tumors are small, have a soft texture, and do not invade the serosa. In this view, our research team has developed a new instrument adapted to minimally-invasive surgery, and manipulated solely by the operating surgeon which has the potential to locate precisely tumors of the digestive tract. It consists of an inductive proximity sensor and an electronic block encapsulated into an autoclavable stainless-steel cage that works in tandem with an endoscopic hemostatic clip whose structure was modified to increase detectability. By scanning the serosal side of the colon or stomach, the instrument is capable to accurately pinpoint the location of the clip placed previously during diagnostic endoscopy on the normal bowel mucosa, adjacent to the tumor. In the current in-vivo experiments performed on large animals, the modified clips were transported without difficulties to the point of interest and attached to the mucosa of the bowel. Using a laparoscopic approach, the detection rate of this system reached 65% when the sensor scanned the bowel at a speed of 0.3 cm/s, and applying slight pressure on the serosa. This value increased to 95% when the sensor was guided directly on the point of clip attachment. The detection rate dropped sharply when the scanning speed exceeded 1 cm/s and when the sensor-clip distance exceeded the cut-off value of 3 mm. In conclusion, the proposed detection system demonstrated its potential to offer a swift and convenient solution for the digestive laparoscopic surgeons, however its detection range still needs to be improved to render it useful for the clinical setting.

Risk factors for positive sentinel lymph node, lymphatic or hematogenous dissemination over time in patients with cutaneous melanoma

The aim of the present study was to assess the influence of localization, age or sex and histopathological characteristics upon the chance of developing lymphatic or hematogenous metastatic spread over time, or a positive sentinel lymph node in cutaneous melanoma patients. Patients from the Department of Dermatology, County Emergency Hospital Cluj-Napoca (Cluj-Napoca, Romania), presenting with cutaneous melanoma confirmed histopathologically and a SPECT/CT or lymphoscintigraphic examination to detect the sentinel lymph node, were included in the present study. Our results revealed that Breslow index >2 mm [odds ratio (OR)=4.22, 95% confidence interval (CI) (1.12; 15.93)], presence of ulceration [OR=6.01, 95% CI (1.87; 19.35)], and positive sentinel lymph node [for at least one sentinel lymph node OR=3.58, 95% CI (1.06; 12.04)] were risk factors for hematogenous metastases. All these, except for the Breslow index >2 mm, were demonstrated to be a risk factor for lymphatic spread metastases over time. Ulceration and male sex also represented risk factors for a positive sentinel lymph node, men having a higher risk of developing sentinel lymph nodes than women [adjusted OR=2.27, 95% CI (1.00; 5.13)]. In conclusion, the predictors that influence the occurrence of lymphatic or hematogenous metastases may differ, ulceration and positive sentinel lymph node being common for both types of metastatic spread, while Breslow index being a significant predictor only for hematogenous metastases. Male sex and the presence of ulceration were demonstrated to be significant risk factors for positive sentinel lymph nodes.

Nipple Ultrasound: A Pictorial Essay

Ultrasound (US) is an attractive diagnostic approach to identify both common and uncommon nipple pathologies, such as duct ectasia, nipple abscess, nipple leiomyoma, nipple adenoma, fibroepithelial polyp, ductal carcinoma in situ (restricted to nipple), invasive carcinoma, and Paget's disease. US is the reliable first-line imaging technique to assess nipple pathologies. It is useful to identify and characterize nipple lesions. Additionally, we have presented the mammography and MRI outcomes correlated with histopathologic features for the relevant cases.

Laparoscopic compatible device incorporating inductive proximity sensors for precise detection of gastric and colorectal small tumors

The accurate localization of small tumors of the digestive tract is of paramount importance in surgical oncology because it dictates the limits of resection and the extent of lymph node dissection. In this view, we have designed and fabricated a highly efficient sensing laparoscopic instrument focused on precise non-invasive extralumenal intraoperative detection of small colorectal or gastric tumors. The equipment is fully adapted for laparoscopic surgery and consists of an inductive proximity sensor encapsulated into a watertight stainless-steel case that is connected to an electronic functional block dimensionally scaled-down by the desired form and size for optimal surgical manipulation. The sensor-case unit and the electronic block are coupled together using a modular system which allows disconnection of the latter and sterilization by autoclavation of the former, followed by swift plugging of the electronic block just before surgery in a sterile-controlled environment. The instrument works in tandem with a modified endoscopic hemostatic clip which is attached endoscopically, before surgery, in the mucosa proximal and distal to the tumor. By scanning the serosal side of the digestive organ during the laparoscopic surgical procedure, the detector senses the modified clip and thus pinpoints to the location of the tumor. Additional engineering of the standard endoscopic hemostatic clips by coating them with various combinations of metallic alloys of Cu and Zn was necessary to improve the detection range and sensitivity without compromising on their functionality. The clips were also covered with nanometric layers of Au to ensure their biocompatibility. The ex-vivo dry-lab experiments showed a satisfactory detection distance which was later confirmed in ex-vivo wet-lab experiments on animal organs and human surgical specimens.

Which is the Optimal Method of Reconstruction After Laparoscopic Right Hemicolectomy, the Intracorporeal or Extracorporeal Anastomosis Technique?

Introduction: The laparoscopic approach to right colectomy is gradually gaining a leading role in the surgical treatment of right colonic diseases. However, not all aspects of the procedure are standardized and the method of reconstruction of the digestive tract is still under debate. The present study critically evaluates the extracorporeal (EA) and intracorporeal (IA) techniques used for creation of the ileocolic anastomosis during a laparoscopic right colectomy. Material and Method: The EA and IA anastomotic techniques are described in detail. The peri operative data of a cohort of consecutive patients operated by our surgical team was retrospectively recorded and analyzed regarding type of anastomosis, the path for transition from EA to IA and the incidence of postoperative complications. Furthermore, an analysis of randomized clinical trials, reviews and meta-analyses that provided a comparative evaluation of EA versus IA was performed to provide a more in-depth integration of our own data into the literature. Results: EA was used at the beginning of our experience but was later replaced by IA which became the favorite anastomotic technique. There was no anastomotic fistula recorded in the EA or IA groups but in our cohort IA was unexpectedly associated with higher incidence of peritoneal drainage, prolonged ileus, surgical site infections, anastomotic bleeding and chyloperitoneum. However, IA allows better visualization of the ileal and colonic stumps, avoids twisting of the anastomosis, prevents extraction-related tearing of the mesocolon and reduces the risk of post operative hernia. Data from the literature also shows that IA is generally associated with earlier postoperative return of bowel function, less morbidity and less postoperative pain. Conclusions: Based on this study and the data currently present in the literature it can not be concluded that IA should be considered as the standard of care for laparoscopic right colectomy. The decision for an EA or IA anastomosis ultimately belongs to the surgeon and is influenced by his surgical skill and experience. The results of ongoing randomized controlled trials on large group of patients may bring more clarity on this issue in the future.

Neutrophil-to-lymphocyte ratio: a hidden gem in predicting neoadjuvant treatment response in locally advanced rectal cancer?

PURPOSE

The link between the pro-inflammatory status, tumor aggressiveness and treatment response has been well established in multiple cancers. Various hematologic and biochemical variables representing surrogates for inflammation have been used as predictive markers. Our primary aim was to assess the prognostic value of neutrophil-to-lymphocyte ratio (NLR) in evaluating neoadjuvant treatment response in locally advanced rectal cancer (LARC).

METHODS

We included 60 consecutive patients with LARC, admitted for surgery, after completing a standard full-course neoadjuvant radio-chemotherapy regimen. NLR and other hematologic parameters were collected one day prior to surgery. Treatment response was assessed on the resection specimens.

RESULTS

On univariate analysis, poor responders had a significantly higher NLR value when compared with good responders: 5.81 (5.40-7.28) vs. 3.51 (2.36-4.04), p<0.0001. NLR retained its significance on multivariate analysis, with an OR of 3.51 (1.54-6.57), p=0.001. A NLR cut-off value of 4.50 had the best predictive value for poor response, with an area under the curve (AUC) of 0.85, sensitivity of 83.3% and specificity of 83.3% (p<0.001). Other hematologic ratios, such as the derived NLR (dNLR) and platelet-to-lymphocyte ratio (PLR) were also significant predictors for poor response, although to a lesser extent when compared to NLR.

CONCLUSION

NLR is a simple and cost-effective predictor for neoadjuvant treatment response in LARC. As more data is generated, clear cut-off values could provide valuable insight regarding the management of LARC.

New inductive proximity sensor platform for precise localization of small colorectal tumors

Location of small gastric or colorectal tumors during a laparoscopic procedure is often imprecise and can be misleading. There is a real need for a compatible and straightforward tool that can be used intraoperatively to help the surgeon in this regard. We emphasize in the present work on the fabrication of a new and innovative inductive proximity switch architecture, fully compatible with laparoscopic surgery and with direct application in precise localisation of bowel tumors. An electromagnetic detection probe optimized for laparoscopic surgery and preconditioned for sterilisation was designed and constructed. Various metallic markers designed to be attached to the gastrointestinal mucosa were used for detection by the probe, from standard endoscopic and laparoscopic haemostatic clips to other custom made tags. Experiments were performed in dry and wet-lab experimental laboratory environment using ex-vivo segments of calf's small bowel and colonic surgical specimens from human patients. The dry-lab detection range varied considerably depending on the metallic component of the tags, from 0.5 mm for the endoscopic hemostatic clip to 3.5 mm for the 0.9 mm thickness stainless-steel custom tags. The latter was actually detectable from the serosal side of the fresh colonic surgical specimens in 85% of the attempts if the scanned area was less than 150 cm² and less than 2 mm of fat was interposed between the probe and the bowel. The newly designed system has the potential to discover metallic tags attached to the bowel mucosa for precise intraoperative laparoscopic location of digestive tumors. Further work is in progress to increase the sensitivity and detection range of the system in order to make it fully compatible with the clinical use.

The Value of Staging Laparoscopy for Optimal Multidisciplinary Treatment in Patients with Gastric Cancer

Introduction: Despite improvements in the conventional preoperative tools used for staging of gastric cancer, their accuracy still needs to be improved. Laparoscopy has the potential to visualize and characterize the tumor, the peritoneal cavity and the lymph nodes and thus to better select patients for the optimal treatment strategy. Material and Method: Patients with gastric cancer staged initially with contrast enhanced computer tomography and endoscopic ultrasound were also evaluated by laparoscopy and laparoscopic ultrasound in a distinct preoperative staging procedure. The perioperative data was recorded in a prospective database and was used to decide within the multidisciplinary team the optimal treatment protocol for each patient. The database was retrospectively reviewed for this study. Results: Among the 20 CT-scan M0 patients analyzed, peritoneal carcinomatosis was detected in 15% of the cases. In other 15% of patients laparoscopy upstaged the tumor and directed the patient towards neoadjuvant chemotherapy. Laparoscopic guided percutaneous core biopsies settled the definitive diagnosis in 3 further cases. In total, laparoscopic staging brought important information in 65% of cases and changed the treatment plan in 30% of patients. Conclusions: In the era of neoadjuvant chemotherapy, laparoscopy has the potential to overcome some of the limitations of the conventional staging methods and offers additional informations which finally change the treatment plan in as much as a third of patients with gastric cancer.

Organ sparing management in rectal cancer. Are we there yet?

BACKGROUND

The "watch and wait" approach has recently been proposed as an alternative to surgery in locally-advanced rectal cancer patients that respond to neo-adjuvant chemoradiotherapy, in order to decrease its negative functional consequences upon the quality of life of these patients. Current methods show low accuracy for the identification of complete responders.

MATERIALS AND METHODS

A review of the literature was conducted for articles published up to March 31th, 2019. Relevant studies were identified using bibliographic searches of Pubmed database. The keywords that were used in various combinations were: "neoadjuvant chemoradiotherapy", "non-operative management", "complete pathological response", "rectal cancer", "biomarkers", "staging".

RESULTS

Magnetic resonance imaging can identify complete responders with a high accuracy using new protocols like diffusion weighted imaging. Positron emission tomography with 18-fluoro-deoxy-glucose shows a sensitivity of 90.9% and specificity of 80.3% for the prediction of complete pathologic response using the change in standardized uptake value. A panel of 15 metabolites was identified and shows potential to discriminate patient resistance and sensitivity to neo-adjuvant therapy (Area Under the Curve 0.80). Furthermore, pre-treatment peripheral blood neutrophil to lymphocyte ratio below 2 and platelet to lymphocyte ratio below 133.4 are significantly correlated with good tumor response (OR 2.49). Analysis of the pattern of carcinoembryonic antigen (CEA) clearance after neoadjuvant treatment conclude that an exponential decrease of the CEA levels is associated with significant tumor down staging and complete pathologic response.

CONCLUSION

New methods of assessing the response to neo-adjuvant therapy in locally-advanced rectal cancer have emerged, showing promising results. Further studies need to assess the best combination between imaging and these biomarkers in order to increase the accuracy and standardize the criteria for non-operative management.

KEY WORDS

Biomarkers, Complete pathologic response, Non-Operative management, Rectal cancer, Staging.

Cervical Exenteration - Guidelines and Surgical Technique Principles

Introduction: Neoplastic invasion of the structures of the cervical region originating from a malignant tumour developed in one of the viscera of the throat may benefit from cervical exenteration. Defined as resection of the hypopharynx, cervical oesophagus, larynx and cervical trachea, exenteration has limited indications and is mandatorily accompanied by digestive tube reconstruction. The aim of this article is to highlight the indication, surgical strategy and important surgical stages illustrated by images from personal professional experience.

MATERIALS AND METHOD

Pharyngo-laryngo-oesophageal en bloc resection and radical cervical lymphadenectomy were followed by reconstruction via free jejunal transfer or colic pedicle grafting. Between 2000 and 2018 we have performed cervical exenteration in 25 patients with tumours originating in the pharynx, larynx or cervical oesophagus. In the cases of 5 patients in whom we did not obtain the oncological safety margin for oesophageal cancer we performed transhiatal pharyngo-laryngo-oesophagectomy. In these patients, we performed reconstruction of the oesophagus with colonic graft. In 20 cases we performed jejunal autotransplant. Results: We recorded 4 perioperative deaths, due to major arterial vessel haemorrhage (1 case), after jejunal necrosis (2 cases), and mediastinitis after oesophageal striping and colonic graft necrosis (1 case). One patient presented tumour recurrence at the level of the tracheal stump. Survival rate varied between 6 months and 4 years for the group of patients who presented for postoperative follow-ups. Conclusions: Cervical exenteration remains an option for tumour recurrence after radiochemotherapy or for obstructive airway or digestive tract tumours. It can be burdened by complications difficult to treat. The surgical team has to adapt its initial surgical strategy to the reality of the surgical field, both in terms of exeresis and in terms of types of pharyngo-oesophageal reconstruction.

Extension of Hepatic Resection Ameliorates Survival in Patients with Type IIIa or IIIb Klatskin Tumors Despite Surgical Complications

Background: Major hepatectomies for hilar cholangiocarcinoma (HC) are associated with high rates of morbidity and mortality. We aimed to evaluate how and if surgical complications related to extended hepatectomies for HC type III and IV according to Bismuth-Corlette classification influence patients long-term survival. Methods: The files of all patients with major hepatectomy for HC and postoperative complications were retrospectively reviewed. Only patients with a complete postoperative follow up have be taken into account for the study. Postoperative morbidity and mortality, length of hospital stay (LOS) as well as overall survival (OS) and disease free survival (DFS) were recorded. Results: Five patients have been found to respond to all inclusion criteria. Three of them required re-operation with one in hospital death. Two patients are still alive and two other died because of the tumor recurrence with a DFS of 36 and 49 months respectively. The actuarial mean OS for the group was 30 months and the actuarial DFS was 26 months. Conclusions: In patients with HC, extensive resections bring a clearly benefit in terms of survival, even though there is an increase in postoperative morbidity and mortality. However, postoperative complications, if managed susccesfully do not interfere with the long-term survival.

SURGERY OUTCOMES IN PATIENTS WITH SECONDARY HYPERPARATHYROIDISM AND IMPACT OF INTRA-OPERATIVE PTH MEASUREMENT

Context

The current therapeutical management of secondary hyperparathyroidism (S-HPTH) is difficult to obtain due to the lack of kidney donors. Surgical intervention on the pathologic parathyroid tissue has been suggested as a method to alleviate symptoms in patients with chronic kidney disease (CKD).

Objective

The aim of our study was to evaluate the outcomes of parathyroid surgery in patients with S-HPTH and the advantages of intraoperative quick PTH (iqPTH) to improve surgical results.

Material and methods

In a real-life study, we compared one group of S-HPTH with iqPTH performed after removing all suspected glands and before wound suture (Group 1) and one group in that iqPTH was not assessed (Group 2). When iqPTH dropped less than 50%, additional exploration followed.

Results

Eight out of the 34 patients from Group 1, who underwent subtotal parathyroidectomy, showed elevated levels of serum PTH and calcium, which remained elevated during follow-up, thus, suggesting disease persistence. From the 21 patients in Group 2, none showed early postoperative disease persistence. Serum calcium, but not PTH was increased in one patient from the iqPTH group but normalized after one month. Overall, iqPTH allowed detection of a supplementary parathyroid gland in one case, thereby increasing early post-surgery remission to 100% in Group 2 compared to 76.47% in Group 1. Late postoperative remission of hyperparathyroidism with no further increase in the rate of hypoparathyroidism was obtained in Group 2.

Conclusions

Assessment of intra-operative PTH levels proved to be a useful tool in augmenting the outcome of S-HPTH surgery. In patients which are eligible for renal transplantation who undergo a subtotal resection, iqPTH can enhance the post-operative quality of life by lowering disease recurrence rates until the kidney transplant procedure.

New trends in breast reconstruction

BACKGROUND

Breast reconstruction (BR) after radical mastectomy is intended to recreate symmetrical natural-appearing breasts while preserving patient safety and quality of life.

PURPOSE

To evaluate the esthetic results and the complications of various BR methods after radical mastectomy.

PATIENTS AND METHOD

Between August 2006 and March 2010, 36 women underwent BR after mastectomy in our institution. Their charts were reviewed retrospectively to evaluate the results and complications. We used immediate BR for Stage I and IIa breast carcinoma, and delayed BR for stage IIb and III breast carcinoma.

RESULTS

We performed a pedicled Transverse Rectus Abdominis Muscle flap in 13 cases, pedicled Latissimus Dorsi with silicone implant in 10 cases, free Deep Inferior Epigastric Perforator (DIEP) flap in 9 cases, and other procedures in four cases. The encountered complications were: total flap failure--one case, partial edge flap necrosis--three cases, donor area wound dehiscence--one case, seroma--one case, local infection--one case.

DISCUSSION

Trends in BR in recent years focus more on free perforator flaps, with the DIEP flap being the leader. Internal mammary vessels are most often used as recipient vessels for anasthomoses. Immediate BR when indicated has better aesthetic results. In less well-developed countries, insurance companies do not cover implant expenses and the autologous procedures remain the best option.

Natural killer group 2 member D cell recruitment driven by major histocompatibility complex class I chain-related antigens A and B: a possible mechanism during acute intestinal allograft rejection in the mouse

Intestinal allograft rejection occurs frequently despite potent T-cell depletion protocols. We investigated the interaction of major histocompatibility complex class I chain-related antigens A and B (MICA/B; a ligand for natural killer [NK] cells) and NK group 2 member D (NKG2D) cells as an alternative mechanism for acute rejection (AR) of the intestinal graft. Heterotopic intestinal allotransplantation was performed from BalbC to C57Bl mice. Samples of grafted and native intestine were obtained at days 1, 3, 6, and 8 after transplantation (n = 4-6). We performed immunostaining for MICA/B and NKG2D. Moderate AR with increased crypt apoptosis was observed at day 6 and advanced AR with crypt destruction and mucosal sloughing was present by day 8. Low MICA/B levels were observed in grafted and native intestines on day 1. MICA/B expression gradually increased in the grafts during AR but not in the native intestines. The up-regulation was found mostly in the crypts. NKG2D+ cell counts that increased in the graft colocalized with MICA/B. The increase was most prominent in the crypt and villus. Together, these results suggest that MICA/B up-regulation and its subsequent interaction with the NK cells may represent an important link between innate and adaptive immune responses early after intestinal transplantation.

Effects of the radiofrequency interference with modified titanium surgical clips on liver parenchyma--an in vivo experiment

AIM

This study sets out to test the biocompatibility of titanium clips in liver, in the presence of radiofrequency. Biocompatibility is assessed at various distances from the RF electrode and different points in time.

METHOD

It is an experimental study conducted on pigs and makes use of histological changes that occur at the liver-titanium interface in presence of RF to test hypotheses. The titanium clips were modified in high vacuum (10 -5 atm) by heating them at 1000 degrees C and 1150 degrees C. Titanium clips were placed in liver at 0.5, 1.5 and 2.5 cm from RF probe. At 7, 14 and 28 days the inflammation, necrosis and fibrosis were assessed.

RESULTS

The histological alterations decrease with the distance of implantation of titanium clips. The inflammation and necrosis nearby the titanium clips decrease in time, but the fibrosis does not increased, as expected. The modified titanium at 1000 degrees C clips cause less necrosis than commercial titanium clips. The moderator role of clip type between distance and cell alteration is empirically supported only for fibrosis and necrosis. The moderator role between time and cell alteration is supported only for inflammation.

CONCLUSIONS

Experimental data suggests there are no preferred surgical clips in all situations. The biocompatibility of the titanium clips depends on the distance from the RF probe. The commercial ones prove less damaging if they are placed close to the RF probe (less than 1 cm) and those that were treated at 1150 C have a better bio-compatibility if placed more than 1 cm from RF probe.

[Accessory renal allotransplantation with internal or external urinary drainage. An experimental model in pig]

This study describes an experimental model of accessory renal allotransplantation in the big laboratory animal (pig). A total of 24 common-breed pigs were used. All allografts were transplanted in an accessory manner and revascularized at the level of the infrarenal abdominal aorta and inferior vena cava. The urinary drainage was performed either through a nexternal uretheroneostomy at the ipsilateral lumbar region (Group A--n=8) or by internal uretheroneocystostomy (Group B--n=8). All transplants were monitored for 8 days postoperatively using translumbar ultrasound-guided biopsies at 1, 4, 7 days. A total of 16 transplants were performed. 1 ectopic donor kidney was found and transplanted in the same fashion. Mean operative time was 125 minutes, immediate postoperative survival was 100% and at 72 hours, 87.5%. The onset of acute rejection was at day 4, by massive lymphocyte infiltration and was directly correlated with the abrupt decrease of the allograft diuresis in Group A, at day 3. At day 7, the rejection was complete. Both methods of urinary drainage are functional and can be employed. This experimental model is a useful tool for training of the transplant surgeons or for transplantation research. The surgical technique for accessory renal allotransplantation in pig is easy to learn and offers the possibility for allograft monitoring until complete rejection without influencing the receptor health condition.

Assessement by laser Doppler of the peripheral tumour perfusion after radiofrequency ablation for colorectal liver mestasis--experimental study

Colorectal cancer became one of the most frequent malignant conditions of the past two decades. Non-resecable liver metastases might be destroyed in situ by radiofrequency although the local recurrence is still very important. Laser-Doppler flowmetry has proved to be a simple technique for monitoring the microcirculation, hereby the tissue perfusion at the edge of the post radiofrequency necrosis. The aim of the study was to evaluate microcirculation using lasser-Doppler for hepatic tissue and peripheral tumour perfusion after radiofrequency and the influence of local temperature increasing at 42 degrees C on tissular perfusion. Colorectal adenocarcinoma (CC531s) was used for liver tumour inoculationin on 15 Wag/Rij rats. Twenty-one days after inoculation, perfusion in hepatic tissue, on the tumour before and after radiofrequency treatment was mesured. When hepatic tissue was heated at 42 degrees C there was an increase in tissular perfusion, on the other part, heating the tumoural tissue do not increase perfusion. After radiofrequency in the periphery of necrosis the perfusion was still present, despite a clear drop towards initial level. Assessing the local microcirculation and tissue temperature during RF ablation by Laser-Doppler might be useful not only for RF efficiency evaluation but also as an indication for associating adjuvant local chemotherapy.

Laser-Doppler flowmetry in the monitoring of the human intestinal allograft: a preliminary report

During acute rejection, graft endothelium becomes a prime target for recipient immune cells. Animal studies have shown reduced microvascular perfusion, probably due to increased endothelial-leukocyte interaction and endothelial impairment, leading to graft damage. Using laser-Doppler flowmetry (LDF), we correlated the microvascular blood flow in the intestinal mucosa of five patients receiving multivisceral grafts with clinical events and pathology results. Measurements (n = 75) were performed during the first 4 weeks posttransplantation by inserting the LDF flexible probe through the ileostomy for 25 to 30 cm. Forty-six of the 75 measurements were performed within 24 hours of endoscopy and biopsy. In uncomplicated cases, we recorded a gradual increase in mucosal perfusion during the first week posttransplantation that presumably reflected regeneration after reperfusion injury. Increased mucosal perfusion did not seem to correlate with rejection or other adverse clinical events. Sudden and sustained decreases in mucosal perfusion by 30% or more compared to the previous measurements were associated with septic episodes, rejection, or both. LDF revealed a good sensitivity in monitoring the intestinal microcirculation. It was able to indicate perfusion changes associated with acute rejection. The relatively low specificity of LDF may be compensated by the low invasivity, allowing frequent investigation. LDF may be an additional tool for routine monitoring of intestinal allografts.

Angiotensin II Receptor Expression Following Intestinal Transplantation in Mice

BACKGROUND

To further improve the success rate of intestinal transplantation there is a need to find early appearing indicators of rejection. The specific aim of this study was to compare Angiotensin (Ang) II type 1 receptor and Ang II type 2 receptor expression in relation to histological signs of rejection.

METHODS

Mice of the C57BL6 strain with syngeneic intestinal grafts were compared to mice subjected to allogeneic intestinal transplantation with BalbC strain as donors. Local expression of Ang II type 1 and 2 receptor was evaluated using rt-PCR and Western blot and compared to histological picture in grafts and native intestine.

RESULTS

The Ang II type 2 receptor protein expression was markedly up-regulated in the allogeneically transplanted graft from day 1 postoperatively. Histological signs of rejection were not seen until day 6.

CONCLUSION

Intestinal allograft transplantation in mice is associated with a marked up-regulation of the Ang II type 2 receptor. However, the detailed role of the renin-angiotensin system in the immune rejection following intestinal transplantation remains to be clarified.

Monitoring of the Intestinal Mucosal Perfusion Using Laser Doppler Flowmetry After Multivisceral Transplantation

BACKGROUND

Graft endothelium constitutes a prime target during acute rejection. Infiltration of T cells, monocytes, and enhanced endothelial-leukocyte interactions result in microvascular impairment and altered perfusion.

MATERIALS AND METHODS

We measured mucosal blood flow using a laser Doppler flowmeter in three patients undergoing multivisceral transplantation. Thirty-seven measurements were performed through the ileostomy over the first 4 weeks posttransplantation. Most measurements were performed within a 24-hour interval from endoscopy and biopsy.

RESULTS

Mucosal perfusion increased throughout the first postoperative week and eventually stabilized around levels specific for each patient. Mucosal perfusion remained stable during graft pancreatitis, but decreased 35% to 55% from baseline (the average value of the previous measurements) during acute rejection and sepsis. During the first week posttransplantation there was a gradual increase in mucosal perfusion, which might reflect regeneration after reperfusion injury. Increased mucosal perfusion did not seem to correlate with rejection or other adverse clinical events. A sudden decrease in mucosal perfusion of 30% or more compared to the previous measurements was associated with septic episodes and/or rejection.

Accelerated acute rejection of the intestinal graft in CD28-Deficient mice

OBJECTIVE

Multiple in vivo studies have shown that the pace and severity of graft rejection is little or not at all changed by deleting CD28 molecules in the recipient. These findings contrast with the effects of monoclonal antibody therapy aimed the same costimulatory target. The objective of the present study was to evaluate how the acute rejection process is affected in CD28-deficient mice using a fully allogeneic, highly immunologically reactive transplant model.

METHODS

Heterotopic vascularized small bowel transplants were performed in 24 recipient mice divided into 4 groups: 2 wild-type and 2 knockout groups. Each group consisted of 5 to 7 animals in which BalbC mice were used as intestinal donors to either wild-type C57BL6 or C57BL6 background CD28-deficient recipient mice. Selected endpoints were 3 and 6 postoperative days (POD). Intestinal rejection was evaluated by mucosal laser Doppler flowmetry (expressed in perfusion units) and histology (expressed in rejection grades).

RESULTS

Acute rejection occurred in both wild-type and CD28-deficient groups. At POD 3, no significant difference was noted between groups in terms of mucosal perfusion and histology. At POD 6, significant differences in graft mucosal perfusion and histology revealed a more aggressive rejection in the CD28-deficient group compared to the wild-type group.

CONCLUSIONS

The present study showed that the severity of intestinal graft rejection responses was amplified by deleting CD28 molecules. Together with data from other studies, these results suggest a different pattern of distribution and/or activation of CD28/B7 receptors in various organs.

Intragraft heat shock protein-60 expression after small bowel transplantation in the mouse

The time course of heat shock protein 60 (hsp 60) expression after intestinal transplantation in syngeneic and allogeneic combination was correlated with the degree of rejection. Hsp 60 expression was assessed by immunostaining; rejection degree was established by histologic examination on posttransplantation days 1, 3, 6, and 8. No signs of rejection occurred in syngeneic grafts at any time. In the allogeneic setting, rejection was absent in all but 1 case on postoperative day 3. Three days later moderate rejection was evident based on focal crypt destruction and focal mucosal ulceration, whereas at postoperative day 8 extensive mucosal sloughing was the dominant feature, consistent with advanced rejection. Hsp 60 remained undetectable in the syngeneic setting at all times. In allografts, hsp 60 was initially expressed on posttransplant day 3, increasing synchronously with the progression of rejection at days 6 and 8. Hsp 60 expression was localized almost exclusively to the crypt area and the lower third of the villi. In conclusion, the rejection of murine allogeneic intestinal grafts is characterized by a progressive expression of hsp 60 in the epithelium.

Laser-Doppler flowmetry is reliable for early diagnosis of small-bowel acute rejection in the mouse

The purpose of the study was to investigate intestinal mucosal perfusion in mouse small-bowel transplantation (SBT), using laser-Doppler flowmetry. Heterotopic SBT was performed in syngeneic and allogeneic combinations. Mucosal perfusion was measured both in the native and in the grafted intestine at time of surgery and at 1, 3, 6, and 8 days postoperatively. Histology specimens were obtained at the same time and graded for rejection. No rejection was seen in the syngeneic group at any of the time points studied. The allografts displayed significant decreased mucosal perfusion on postoperative days 3, 6, and 8. Rejection was histologically evident on postoperative days 6 and 8. Laser-Doppler perfusion in the rejecting intestinal allograft was decreased before onset of histological features of rejection. Mucosal blood flow measured by laser-Doppler could be used as an early indicator of acute rejection in SBT.

Heterotopic uterine transplantation by vascular anastomosis in the mouse

A method of heterotopic uterine transplantation was developed in the mouse as a model system for studies of uterine function and transplant immunology of the uterus. The model involved transplantation of the right uterine horn and the cervix by vascular anastomosis to a donor animal with the intact native uterus remaining in situ. F1-hybrids of inbred C57BL/6 x CBA/ca (B6 CBAF1) mice of 6-8 weeks of age (n=42) were used. The specific pelvic vascular anatomy of these mice was first examined by intra-aortal injection of a two-component silicon-rubber curing agent. The surgery of the donor animal involved microsurgical isolation of the right uterine horn and the cervix, with preserved vascular supply from the aorta through the right uterine artery. After isolation of the uterine horn with vascular supply and venous drainage, including approximately 3 mm of the inferior vena cava and aorta, the organ was put on ice. The recipient animal was prepared by exposing and mobilizing the infrarenal part of the aorta and the vena cava. The grafted uterus was placed in the abdomen on the left side and the aorta and vena cava of the graft were anastomosed end-to-side to the aorta and vena cava of the recipient animal with 11-0 sutures. The total time for these procedures declined with time and was 125+/-4 min for the last 28 operations. Viability of the uterus was confirmed, several days later, by demonstrating a blood flow similar to that of the native uterus, and histology of the grafted uterus demonstrated normal morphology, including intact ultrastructure of the endothelial cells. The overall survival rate of the recipient animals increased with learning from approximately 40% in animals 1-21 to 71% in animals 22-42. The proportion of viable grafts, as judged by normal blood flow and histology among the surviving mice was 25% in animals 1-21 and 87% in animals 22-42. An undisturbed function of the transplanted uterus horn was finally demonstrated by its ability to implant inserted blastocysts and to carry pregnancy with fetal weight being similar to that of fetuses in the native uterus and controls. In conclusion, this is the first report of successful transplantation of the uterus with proven functionality in the mouse. The model should be useful for many aspects of research in uterine physiology and pathophysiology.

[Stapled anastomoses in colorectal surgery]

The purpose of this paper was to analyze the advantages, indications and results of stapled circular anastomoses in colorectal surgery. In the last four years (1995-1998), fifteen patients underwent stapled anastomoses after Dixon's anterior rectal resection for cancers of upper and midrectum (11 patients), total colectomy with ileorectal anastomosis for malignant familial polyposis (1 patient), segmental colectomy of transverse and descending colon (1 patient with synchronous colic and rectal cancers, having concomitant rectal resection for cancer), previous Hartmann's resection for perforated upper rectal cancer (1 patient) or distal sigmoid diverticulitis (1 patient). The anastomoses have been performed in end-to-end fashion (11 patients), according to the Knight's technique (2 cases) or in side-to-end fashion (2 patients). As most frequent associated technique with stapled anastomoses, anterior rectal resection for cancer was performed with 2 cm of clearance beyond the macroscopic margin of tumor. Distal margin of resection was histologically verified and it proved to be free of tumor cells. There was no operative mortality. Anastomotic leakage occurred in three patients because of imperfection of stapled anastomosis (2 cases) or after local irradiation (1 case). Spontaneous closure was seen in one patients. The other two patients needed reoperation for suture or colostomy. Late clinical, endoscopic and X-ray controls did not discover local recurrences. Functional results were good in terms of stool frequency and continence. In conclusion, stapled fashioned anastomoses have the main indication in sphincter saving Dixon's and Hartmann's procedures. In these cases, stapled anastomoses are easier than manual technique, reduce operative time and improve suture reliability.

[The indications for celiostomy in acute necrotizing pancreatitis]

The aim of this study was to analyze the indication and results of open pancreatic drainage by celiostomy in severe necrotizing pancreatitis (SNP). 44 patients with SNP were treated surgically by open lesser-omental sac drainage (celiostomy) in the last nine years (1989-1997). They were classified into three groups according to date (timing) of celiostomy: a group of 23 patients with early celiostomy (in the first week after the onset of pancreatitis); second group of 11 patients with celiostomy in the second and third week after SNP; the third group of 10 patients with late celiostomy (4-12 weeks after pancreatitis). Drainage procedure consisted in marsupialization of lesser omental sac by suturing open gastrocolic ligament to anterior peritoneum, with drains inserted via celiostomy. The indications of celiostomy in the first group were: diagnostic laparotomy for unknown acute abdomen (18 patients), severe acute cholecystitis (1 patient), common bile duct stones (2 patients), persistent MOSF (1 patient). The necrosectomy was technically possible only in eight patients (34.7%) at date of laparotomy. Postoperative infection of necrosis occurred in seven patients (30.4%) and nine patients died postoperatively (39.1%) because of aggravated MOSF. In the second group, celiostomy was carried out for extensive sterile (2 patients) or infected necrosis (9 patients). Good results were obtained in 9 patients and two patients with infected necrosis died postoperatively. In the third group late celiostomy was performed for treatment of the pancreatic abscess, with good results in all patients (0% mortality). In conclusion, celiostomy is drainage procedure of choice for patients with extensive infected pancreatic necrosis or pancreatic abscesses and stable biologic condition. It facilitates intermittent debridements of residual necrosis and purulent foci, without relaparotomies. Early celiostomy is not recommended as it is proved ineffective (nondemarcated necrosis) and may cause aggravation of SNP or exogenous infections of necrosis.