Near-Infrared Indocyanine Green-Enhanced Fluorescence and Evaluation of the Bowel Microperfusion During Robotic Colorectal Surgery: a Retrospective Original Paper

BACKGROUND

Leakage of the anastomosis after colorectal surgery is a severe complication, and one of the most important causes is poor vascular supply. However, a microvascular deficit is often not detectable during surgery under white light. Near-infrared indocyanine green (ICG)-enhanced fluorescence may be useful for assessing microvascular deficits and conceivably preventing anastomotic leakage.

OBJECTIVES

This paper presents a preliminary retrospective case series on robotic colorectal surgery. The aim is to evaluate the feasibility, safety and role of near-infrared ICG-enhanced ?uorescence for the intraoperative assessment of peri-anastomotic tissue vascular perfusion.

MATERIALS AND METHODS

From among more than 164 robotic colorectal cases performed, we retrospectively analyzed 28 that were all performed by the same surgeon (PCG) using near-infrared ICG-enhanced fluorescence technology: 16 left colectomies (57.1%), 8 rectal resections (28.6%), 3 right colectomies (10.8%) and 1 pancolectomy (3.6%).

RESULTS

The rates of conversion, intraoperative complications, dye allergic reaction and mortality were all 0%. In two cases (7.1%)-1 left and 1 right colectomy-the level of the anastomosis was changed intraoperatively after ICG showed ischemic tissues. Despite the application of ICG, one anastomotic leak (after left colectomy for a chronic recurrent sigmoid diverticulitis with pericolic abscess) was observed.

CONCLUSIONS

ICG technology may help to determine when to intraoperatively change the anastomotic level to a safer location. In our case series, ICG results led to a change in the level of the anastomosis in 7.1% of the cases. Despite the use of ICG, we observed one leak. This may have been related to vascularization-independent causes (e.g., infection in this case) or may reflect a need for better standardization of this ICG technology. In particular, we need a way to objectively assess the ICG signal and the related risk of leakage. More randomized, prospective, well-powered trials are needed to unveil the full potential of this innovative surgical technology.

Diagnostic value of intestinal fatty acid-binding protein for pneumatosis intestinalis

BACKGROUND

Pneumatosis intestinalis (PI) is known as a sign of a life-threatening bowel ischemia. We aimed to evaluate the utility of intestinal fatty acid-binding protein (I-FABP) in the diagnosis of pathologic PI.

METHODS

All consecutive patients who presented to our emergency department with PI were prospectively enrolled. The diagnostic performance of I-FABP for pathologic PI was compared with that of other traditional biomarkers and various parameters.

RESULTS

Seventy patients with PI were enrolled. Pathologic PI was diagnosed in 27 patients (39%). The levels of most biomarkers were significantly higher in patients with pathologic PI than those with nonpathologic PI (P < .05). Receiver operator characteristic analysis revealed that the area under the curve (AUC) was highest for I-FABP (area under the curve = .82) in the diagnosis of pathologic PI.

CONCLUSIONS

High I-FABP value, in combination with other parameters, might be clinically useful for pathologic PI.

An unusual outcome of a giant ventral hernia

Hernias are routine general surgical problems that may present in any age group, regardless of the patient’s socioeconomic status. We present a rare case of a complicated ventral hernia leading to short bowel. This is an unusual case and is very rarely reported in the literature. This current case report describes a 54-year-old gentleman who presented to the hospital with a giant strangulated ventral hernia causing massive bowel ischemia and resulting in a short bowel. The literature on large abdominal wall hernias leading to short bowel is reviewed, and a discussion on short bowel syndrome is also presented.

[Pathomorphological peculiarities of hemomicrocirculatory bed of the small and large intestine in acute peritonitis]

Experimental comparative morphological investigation of hemomicrocirculation bed (HMCB) of the small and large bowel wall was performed in dynamics of an acute serous peritonitis. Spreaded aseptic peritonitis was simulated using injection of 5 ml of gamma-caraginen (Sigma, USA) in 1 ml of isotonic solution of sodium chloride. On the early stage of peritonitis (in 12 h from beginning of the experiment) in mucosa of small bowel nonsignificant venuls dilatation and the capillary lumen reduction were observed. In 1 day (reactive stage of peritonitis) in mucosa the quantity of capillars have had reduced significantly, comparing with such observed previously. On the 2-nd day (toxic stage of peritonitis) some capillary dilatation in intestinal villi and crypts coexistant with the blood rheology disorders in a form of stasis, change in permeability of the vessels walls, predominantly of the venous, was noted. On the 3-d day (late stage) the arteriol's spasm have had reduced, capillary paralytic dilatation was revealed. The staged course of experimental peritonitis with the HMCB changes, characteristic for every stage, was confirmed, basing on analysis of the investigation result.

[The risk factors of the sutures insufficiency and the choice of the anastomosis formation method during reconstruction-restoration operations on the large bowel]

Basing on statistical analysis of 17 prognostic risk factors for occurrence of the sutures insufficiency in a large bowel anastomoses (SILBA) in 237 patients there was established a trustworthy correlational connection for 7 factors. The results of a regression analysis have had confirmed the influence of the anastomosis formation method on the complication rate, demonstrated by an active inflammation in the anastomosis formation area, technical faults while the wall mobilization and rude formation of sutures, intramural disorder of the blood circulation, the blood circulation general disorders, local infectioning and hypoproteinemia. Application of analysis of the tables of conjunction and comparison in accordance with the numeral and interval predictors, using nonparametric analysis (the method of a binary logistic regression), have permitted to delineate the most prognostically significant risk factors of the SILBA occurrence.

Intraoperative contrast-enhanced sonography of bowel blood flow: preliminary experience

OBJECTIVES

The potential to predict, and therefore avoid, anastomotic failure has eluded generations of colon and rectal surgeons to date. A reliable, reproducible method of assessing bowel blood flow therefore would be of enormous potential clinical relevance. To our knowledge, intraoperative contrast-enhanced sonography of the bowel has not been performed previously. We present our study assessing the feasibility of using contrast-enhanced sonography to study bowel perfusion intraoperatively.

METHODS

We studied 8 patients (4 male and 4 female) with an age range of 52 to 81 years who underwent colorectal surgery (right hemicolectomies, n = 3; Hartmann procedure, n = 1; anterior resections, n = 2; and bowel resections with ileocolic anastomoses, n = 2). A 5-mL bolus of a sulfur hexafluoride contrast agent solution was injected before and after vascular ligation with simultaneous noncompression ultrasound scanning directly over the large bowel. The patients were followed clinically to assess for leaks. Contrast-enhanced sonographic time-intensity curves were generated for the time to peak and maximum amplitude.

RESULTS

Moderate interobserver agreement was shown for the time to peak (κ = 0.50) and maximum amplitude (κ = 0.42), and moderate intraobserver agreement was shown for the time to peak (κ= 0.53) and maximum amplitude (κ= 0.53). No significant differences were shown between the time to peak (P = .28) and maximum amplitude (P = .49) for the preligation and postligation scans.

CONCLUSIONS

To our knowledge, intraoperative contrast-enhanced sonography of the bowel has not been performed previously. We have shown the technique to be feasible with good intraobserver and interobserver agreement. Further work is ongoing to optimize the technique and assess its use in predicting anastomotic breakdown.

The spatial arrangement of the human large intestinal wall blood circulation

The aim of the study was to describe and depict the spatial arrangement of the colon microcirculatory bed as a whole. Various parts of the large intestine and terminal ileum were harvested from either cadaver or section material or gained peroperatively. Samples were then injected with India ink or methylmetacrylate Mercox resin for microdissection and corrosion casting for scanning electron microscopy. The results showed that extramural vasa recta ramified to form the subserous plexus, some of them passing underneath the colon taeniae. Branches of both short and long vasa recta merged in the colon wall, pierced the muscular layer and spread out as the submucous plexus, which extended throughout the whole intestine without any interruption. The muscular layer received blood via both the centrifugal branches of the submucous plexus and the minor branches sent off by the subserous plexus. The mucosa was supplied by the mucous plexus, which sent capillaries into the walls of intestinal glands. The hexagonal arrangement of the intestinal glands reflected their vascular bed. All three presumptive critical points are only gross anatomical points of no physiological relevance in healthy individuals. Neither microscopic weak points nor regional differences were proven within the wall of the whole large intestine. The corrosion casts showed a huge density of capillaries under the mucosa of the large intestine. A regular hexagonal pattern of the vascular bed on the inner surface was revealed. No microvascular critical point proofs were confirmed and a correlation model to various pathological states was created.

Effects of cyclooxygenase inhibition on anastomotic healing following large bowel resection in a rabbit model--a randomized, blinded, placebo-controlled trial

PURPOSE

We performed an experimental study in a rabbit model to investigate the effects of a selective Cox-2 inhibitor (Valdecoxib) on anastomotic healing following large bowel resection after 1 week.

MATERIALS AND METHODS

Eighty New Zealand white rabbits were randomized into four groups and underwent a colon resection with end-to-end anastomosis. Group 1 (n = 20) was treated with Valdecoxib, group 2 with Metamizole (Novalgin), group 3 with Resveratrol (specific Cox-1 inhibitor), or a placebo vehicle with similar volume (group 4). Anastomotic healing was tested at the seventh postoperative day by measurement of the bursting pressure in vitro. Immunohistochemical staining of the anastomotic site was performed with polyclonal antibodies (CD31).

RESULTS

There were no significant differences in anastomotic dehiscence, bursting pressure, or vessel density between the treatment and control groups.

CONCLUSION

The application of Valdecoxib does not influence anastomotic healing or new vessel formation in the anastomotic region following large bowel resection.

[Programmed relaparotomy in treatment of upper mesenteric artery acute occlusion]

Results of surgical treatment and frequency of intestinal necrosis in 44 patients with acute mesenterial circulation failure were analyzed. Instrumental method of detecting the border of necrosis by the infracted intestine should allow refuse programmed relaparotomies in treatment of such patients and perform a sole operation with intestinal resection and anastomosis.

Isolated polyarteritis nodosa of the large bowel: a case report

Polyarteritis nodosa is a form of vasculitis that affects several organs. Gastrointestinal involvement is frequent, but cases in which the gastrointestinal tract is the only site of disease are rare. In this paper we report a case of a 70-year-old patient with polyarteritis nodosa restricted to the large intestine, who underwent a total colectomy. The patient had no other signs of chronic vasculitis and for this reason surgical treatment resolved the clinical symptoms.

Vagal innervation of intestines: afferent pathways mapped with new en bloc horseradish peroxidase adaptation

Neural tracers have not typically been employed to determine the pathways followed by axons between their perikarya and target tissues. We have adapted the tetramethylbenzidine method for horseradish peroxidase (HRP) to stain fibers en bloc in organs and thus to delineate axonal trajectories. We have also applied this protocol to characterize the pathways that vagal afferents follow to the intestines. The protocol confirms that the proximal segment of the duodenum receives afferents carried in the vagal hepatic branch and demonstrates that vagal afferents innervating the remainder of the small and large intestines course through multiple fascicles derived from the celiac branches of the abdominal vagus. These fascicles divide, intermingle, and reorganize along the abdominal aorta and superior mesenteric artery (SMA), but not along the inferior mesenteric artery, and then project to the intestines with secondary arteries that branch from the SMA. The inferior pancreaticoduodenal, jejunal, middle colic, right colic, and ileocecocolic arteries all carry vagal afferents to segments of the intestines. As the arteries derived from the SMA divide repeatedly into successively finer branches and course to the intestines, the vagal afferent fascicles (typically a pair) running with each arterial branch also divide. These divisions generate sets/pairs of finer fascicles coursing with even the highest order arterial radicles. The vagal fascicles enter the intestinal wall with the vessels and appear to innervate the organ near the point of entry. The results verify the practicality and sensitivity of the en bloc HRP technique and suggest that the protocol could delineate other peripheral pathways.

[Obstructive ileus of the large intestine caused by ischemic colitis--literature review and report of 7 cases]

Ischemic colitis is the most common form of intestinal ischemia. The damage produces ulcers in the lining of the large intestine. Ischemic colitis affects primarily people who are 50 or older. The disease was first described by Boley and associates [1] as a "reversible vascular occlusion" of the colon, and Marston and colleagues [2] went on to detail the gangrenous, stricturing, and transient forms. Two mechanisms may cause bowel ischemia: The first and most common is diminished bowel perfusion due to low cardiac output often seen with in patients with cardiac disease or in prolonged shock of any etiology. The second mechanism is occlusive disease of the vascular supply of bowel due to atheroma, thrombosis, or embolism in which the collateral circulation is not adequate to maintain bowel integrity.

Gastro-colonic anastomosis--a viable option in extensive small bowel infarction

INTRODUCTION

We have previously presented a patient with massive small and large bowel infarction and demonstrated that even with only a few inches of remaining small bowel an almost normal life-style and diet is possible.

PATIENT

Recently, we have looked after a young and otherwise fit female patient who suffered mesenteric venous gangrene of the whole small bowel from the Ligament of Treitz to the caecum. In order to achieve gastro-intestinal continuity and to avoid the torrential fluid loss associated with high fistula, an anastomosis between the stomach and the transverse colon was formed.

RESULTS

We are surprised to find that despite the extensive resection our patient maintains a good quality of life and is able to look after her young family.

Calcific uremic arteriolopathy presenting with small and large bowel involvement

Calcific uremic arteriolopathy (CUA) is a rare complication of end-stage renal disease in which thrombosis occurs in calcified arteries, leading to infarction and infection of the affected tissues. This brief report describes a fatal case of CUA which presented with intestinal involvement, significantly before the onset of classical skin lesions. It is essential to raise awareness of this rare but clinically relevant form of presentation of CUA. The diagnostic and treatment issues are discussed in this case.

Celiomesenteric trunk compression and absence of collateral vessels in the large intestine--a case report

The authors report the case of a rare mesenteric anomaly in a 71-year-old man who presented with a preexisting abdominal aortic aneurysm (AAA) and a progressive history of postprandial abdominal pain and 10-lb weight loss. Aortography revealed a common celiomesenteric trunk, an absent middle colic artery, and a stenotic inferior mesenteric artery. At operation, neural fibers compressing the common celiomesenteric trunk were lysed, the AAA was repaired, and the inferior mesenteric artery was subjected to endarterectomy and then reimplanted. The patient remains well and free of symptoms 1 year after operation. This rare case demonstrates the many different causes of intestinal angina and its surgical relief.

Embolization for major lower gastrointestinal haemorrhage: five-year experience

The management of major lower gastrointestinal haemorrhage has changed dramatically in the last 15 years. Innovations in coaxial catheter technology have allowed the interventional radiologist to reach the small peripheral mesenteric arteries and perform superselective embolization with a variety of agents. The present large series represents the 5-year experience of this technique at the Alfred Hospital, Melbourne, in a patient cohort with a high number of comorbidities. Technical success was achieved in 96% of cases. The clinical symptoms of mesenteric ischaemia developed in four patients after embolization and were managed conservatively in two. The procedure-related mortality was low when compared with the published complication rates for emergency surgery, in this clinical setting.

[Intestinal microvessels in patients of different ages after an appendectomy]

The numbers and diameters of microcirculatory bed vessels located in the wall of various regions of small and large intestine, were determined in 43 patients of lirst and second mature ages and in 19 aged and senile patients less than one year - more than ten years after an appendectomy. In was established that during the first year following the operation, the number of arterioles, capillaries and venules per standard area of the section in middle-aged patients was increased in the wall of caecum and ileo-caecal transition with a concomitant increase in the lumen of these vessels. These changes were most pronounced in capillaries, while arterioles were less affected. Vascular changes were expressed in the wall of caecum close to post-operational scar and in the wall of ileo-caecal transition, but in the wall of middle part of small intestine and middle part of colon transversum they disappeared. Three years following the operation, the numbers of microcirculatory bed vessels and their luminal diameters were similar to those found in people with an intact appendix. The changes described were not detected in aged and senile persons.

Ischemia-reperfusion injury of the intestine and protective strategies against injury

Ischemia-reperfusion injury of the intestine is a significant problem in abdominal aortic aneurysm surgery, small bowel transplantation, cardiopulmonary bypass, strangulated hernias, and neonatal necrotizing enterocolitis. It can also occur as a consequence of collapse of systemic circulation, as in hypovolemic and septic shock. It is associated with a high morbidity and mortality. This article is a comprehensive review of the current status of the molecular biology and the strategies to prevent ischemia-reperfusion injury of the intestine. Various treatment modalities have successfully been applied to attenuate reperfusion injury in animal models of reperfusion injury of the intestine. Ischemic preconditioning has been found to be the most promising strategy against reperfusion injury during the last few years, appearing to increase the tolerance of the intestine to reperfusion injury. Although ischemic preconditioning has been shown to be beneficial in the human heart and the liver, prospective controlled studies in humans involving ischemic preconditioning of the intestine are lacking. Research focused on the application of novel drugs that can mimic the effects of ischemic preconditioning to manipulate the cellular events during reperfusion injury of the intestine is required.

[Arterial anatomy of the sigmoid colon useful for colon take down techniques]

BACKGROUND

An anatomic study about the arterial vascularization of the sigmoid was performed in order to obtain guidelines for the surgical treatment of rectal carcinoma.

AIM

In the proposed technique, the sigmoid is brought down to the perineum, after radical anal-rectal resection, including sphincterectomy.

MATERIAL AND METHODS

Thirty-three anatomical pieces were obtained through in situ dissection of formolized corpses (22 were male and 11 female). Turpentine solution, red marking, polyvinyl chloride were the materials used for preparation after catheterization of the inferior mesenteric artery.

RESULTS

The inferior mesenteric artery originated in most cases from the left side of the abdominal aorta, approximately 4.3 cm fromits bifurcation point; the left colonic artery, in 25 cases, originated straight from the inferior mesenteric artery below the left colonic artery, after which the sigmoid would be brought down to the perineum.

CONCLUSION

Knowledge about arterial vascularization of the sigmoid could be helpful in the surgical management of rectal cancer.

[Clinical-functional and morphological changes in the large intestine in patients with chronic abdominal ischemia]

The article presents a study of clinical variants of ischemic lesions of the large intestine (ILLI) in patients with the chronic abdominal ischemia (CAI) syndrome. There was an examination of 42 patients with putative ILLI, who had a cardiovascular pathology at the background, which led to significant hemodynamic disorders of the blood flow in unpaired visceral branches of the abdominal aorta. The authors performed a complex diagnostics of ILLI including anamnestic and clinical data, laboratory and morphological assessment of the large intestine and vessels providing its blood supply. Based on the data collected, other functional and organic diseases of the large intestine (LI) were excluded. It was revealed that the final result of ILLI differed depending on the ischemia degree--from reversible functional disorders to high-grade organic lesions of the LI. Each clinical variant of ILLI has its own clinical manifestations as well as functional, organic and morphological peculiarities of changes in the LI revealed by a laboratory and histological examination of the LI.

Abdominal complications after cardiac surgery in cardiopulmonary bypass

Gastrointestinal problems are an infrequent but serious consequence of cardiac surgery that includes cardiopulmonary bypass. Predictors of these complications are not well developed, and the role of fundamental variables remains controversial. Between July 1998 and August 2002, 1,552 patients (1,106 male and 446 female), mean age 56 years, underwent heart surgery with cardiopulmonary bypass. Among those 1,552 patients, 21 (1.35%) had gastrointestinal complications, mainly because of gastrointestinal bleeding due to gastritis and five of them required surgery. We present these five patients, three with intestinal ischemia, two with intestinal bleeding. There Hoffmeister-Finsterer operation, Rydygier resection, hemicolectomy, appendectomy with cecum sewing and sigmoid resection were performed. The mortality in this group was 60% (three of five), and the cause of death was multiorgan insufficiency.

CONCLUSION

Careful monitoring and physical examination of these high-risk patients following cardiac surgery is required for early detection and effective treatment.

Vascular anatomy of the gastrointestinal tract

The blood supply of the gastrointestinal system has intramural and extramural components. The intramural vascular distribution is generally well developed with plexuses in the different layers of the bowel wall and with specializations in the liver, small intestine and gastroesophageal junction, adapted to the function of these organs. The extramural arterial supply for the oesophagus is derived from the thoracic aorta or its major branches. Blood supply to the abdominal organs is provided by three major unpaired vessels arising from the abdominal aorta, namely the coeliac trunk and the superior and inferior mesenteric arteries. The branches of these vessels form anastomotic systems that provide a rich blood supply to the adjoining organs. In many areas the systems overlap while in other regions linkages are limited. Interrelations and weak points are of significant clinical importance. As well as this, there is a great individual variability in the anatomy of the gastrointestinal vasculature.

Acute intestinal ischaemia

The subsets of acute mesenteric ischaemia include mesenteric arterial occlusion (by embolus or thrombosis), mesenteric venous thrombosis and non-occlusive mesenteric ischaemia. Despite advances in pathophysiology, laboratory diagnosis and imaging techniques, acute mesenteric ischaemia is still associated with mortality rates of more than 60% and continues to be a challenging diagnostic problem. The key to a better outcome (and the main problem in clinical practice) is early diagnosis. Clinical presentation may be unspecific, but is often characterized by an initial discrepancy between severe subjective pain and relatively unspectacular findings on physical examination. Up to now, there are no simple and non-invasive diagnostic tests of sufficient sensitivity and specificity; thus, angiography remains the cornerstone of diagnosis and should be performed early in all patients in which mesenteric ischaemia is a realistic differential diagnosis. Treatment for obstructive mesenteric arterial syndromes and most patients with mesenteric venous thrombosis is surgical, whereas non-occlusive mesenteric ischaemia may be managed by pharmacological vasodilation.

[Anatomic-topographic description of the stomach, small intestine, large intestine and their arteries of the greater mara (Dolichotis patagonum Desmarest 1820)]

The abdominal parts of the alimentary canal and the associated arteries from seven male and nine female maras are described. The mara possesses a stomach with a single cavity and a glandular mucosa lining. The large stomach is situated caudal of the liver at right-angles to the longitudinal body axis. The long jejunum is located on the left side of the body caudal of the stomach. The cecum has two teniae and numerous haustra which are proximal larger than distal. The smooth colon ascendens runs proximal parallel to the cecum and describes distal an U-shaped double-loop. The internal surface of the proximal part of the colon ascendens is characterized by two parallel mucosal ledges. Cecum and colon ascendens lie right caudal of the liver. The colon descendens is coiled and situated on the left body side. The A. gastrica sinistra and branches of the A. lienalis and the A. hepatica supply the stomach. The A. mesenterica cranialis which branches of separately from the A. coeliaca is a large and long vessel that supplies the major parts of the small intestine and the colon. The A. mesenterica caudalis supplies parts of the colon desendens and of the rectum.

Myoelectric assessment of large bowel viability: an experiment in dogs

OBJECTIVE

To design a device for myoelectric assessment of intestinal ischaemia and compare it with every day surgical experience and Doppler signals recorded on the bowel wall.

DESIGN

Experimental study.

SETTING

Thessaloniki university hospital, Greece.

MATERIAL

12 adult mongrel dogs.

INTERVENTIONS

On the first day the large intestine was devascularised for a length of 20 cm, 5 cm away from the ileocaecal valve, and the threshold of the electric stimulus (mA) required to produce a contraction of the normal large bowel was recorded. On the second day, measurements were made on the ischaemic segment of the large bowel at 0.5 cm intervals. Bowel resection and anastomoses were done at the stimulus level of 40 mA.

RESULTS

The mean (SD) stimulus threshold of the normal large intestine was 12.2 mA. The necrotic intestine demanded current stimulus of 100 mA or failed to contract. On the eighth postoperative day the animals were killed to assess anastomotic healing. Of the 12 anastomoses made at the 40 mA stimulus point, only one ruptured. The 40 mA limit of the stimulus level seems to be of value in assessments of bowel viability in vivo.

CONCLUSION

The use of a personal computer as a read out device makes myoelectric analysis easier and more reliable in the assessment of intestinal viability. This method may have a clinical application.

[Vascular complications in intestinal obstructions. The role of computed tomography]

INTRODUCTION

We investigated CT capabilities in showing vascular complications (ischemia, infarction) secondary to intestinal obstruction.

SUBJECTS AND METHODS

32 patients with small bowel obstruction, subdivided in two groups, were examined with CT. The first group consisted of 12 patients with small bowel obstruction complicated by ischemic injury. It was due to loop strangulation in 10 cases and loop distension secondary to colon carcinoma in 2 cases. At surgery the loop strangulation was caused by adhesions in 9 cases and by jejunal hernia in 1 case. Vascular complications were segmentary small bowel infarction in 7 cases, colonic infarction in 2 cases and ischemia, which was resolved after loop debridement, in 3 cases. The second group consisted of 20 patients with intestinal occlusion due to adhesions complicated by a closed loop in 4 cases. All patients were examined with(out) i.v. contrast agent administration. Filling of the intestinal loops by oral contrast agent was never performed.

RESULTS

CT identified the vascular injury secondary to intestinal obstruction in 11/12 patients (91%). In one case it was not possible to diagnose mild ischemia, which was found of surgery. CT findings were: loops distention in all the cases; wall thickening in 11 cases with intramural gas in 8 cases and slight contrast enhancement in 1 case; ascites in 2 cases; mesenteric edema in 9 cases; gas at the mesenteric root in 1 case. In the control group, small bowel obstruction was diagnosed with CT in all cases based on the presence of distended loops up to the occlusion site. Parietal alterations above the lesion were never found.

CONCLUSION

CT is a sensitive tool for diagnosing small bowel obstruction and for assessing the site and cause of obstruction. CT plays a pivotal diagnostic role in vascular complications, giving very important indications for a correct treatment.

Changes of angiogenesis and tumor cell apoptosis during colorectal carcinogenesis

Activation of the angiogenic process occurs during tumorigenesis, as does disturbance of cell proliferation and apoptosis. Seeking a potential correlation, we investigated tumor cell apoptosis, proliferation, and angiogenesis in the adenoma-carcinoma sequence of colorectal carcinogenesis using an in situ apoptosis detection kit and MIB-1 and anti-CD34 antibodies in 27 adenomas with low dysplasia, 17 adenomas with high dysplasia, and 26 carcinomas in adenoma, as well as assessed p53 and bcl-2 expressions. The results showed that the potential for apoptosis was augmented, paralleling the increment of proliferation, in adenomas with low dysplasia but diminished when adenomas progressed from low dysplasia to high dysplasia and cancer. A gradual increment of microvessel density was observed during the progression with an increase during transition from low dysplasia to high dysplasia and cancer. Correlation coefficient test showed an inverse correlation between apoptotic index and microvessel density when all of the lesions were taken into account. No apparent impact of aberrant p53 on angiogenesis or bcl-2 on apoptosis was observed in this study. These results suggest that the angiogenesis initiates during transition from low dysplasia to high dysplasia and cancer, which may, in turn, contribute to the reduction of tumor cell apoptosis during colorectal carcinogenesis.

Giant cell phlebitis as a cause of large intestinal stricture

Although arteritis of the gastrointestinal tract is well known, an isolated phlebitis without associated arteritis of the colon and cecum is rare. We describe a distinct form of giant cell phlebitis in a 16-year-old girl causing ischemic stricture of the large intestine. She presented with subacute intestinal obstruction and was suspected of suffering from tuberculosis. However, histopathologic examination showed giant cell phlebitis, the arterioles and arteries being spared. Although this is an extremely rare form of nonprogressive vasculitis, it should be considered in the differential diagnosis of strictures in the large intestine, especially in the young.

[Intramural blood vessels of the large intestine of the horse (Equus przewalskii f. caballus)]

The vascular system of the large intestine of 12 horses was examined by means of vascular corrosion casts, histology and transmission electron microscopy providing the following results. The Aa. et Vv. breves et longae leave the mesenteric vessels, respectively the subserously on the teniae lying cecal vessels to reach the tela subserosa at the mesenteric margin. The short vessels enter the deeper layers of the wall instantly, whereas the Aa. et Vv. longae move towards the submucosa by penetrating the muscular layers after a variable subserous course. The tela submucosa contains an arterial and a venous vascular plexus. In broader areas of the submucosa a three-dimensional vascular network can be found. This consists of a deep and a superficial vascular plexus, which are closely interconnected. The deep plexus is applied to the inner circular muscles, whereas the superficial plexus is adjacent to the muscularis mucosae. The (deep) arterial plexus receives its afflux from the Aa. breves et longae and supplies parts of the circular muscle layer with recurrent muscle branches. The vascularisation of the mucosa also originates from the submucosal (superficial) plexus. In the basal tunica mucosa, the ascending arteries form a transversal network from which arterioles branch into periglandular capillaries around each Lieberkühn crypt. Close to the lumen, a polygonal subepithelial capillary system is formed. The capillaries turn into postcapillary venules immediately below the epithelium of the mucosal surface. Veins move vertically through the submucosa to enter the submucosal plexus after few inflowing side branches. Branches of the subserous-submucosal connections form an intermuscular plexus between the circular and longitudinal muscular layer. This plexus supplies the capillaries of the tunica muscularis. The subepithelial capillaries are predominantly lined with a fenestrated endothelium, whereas the capillaries of the pericryptal mucosa mainly show a continuous endothelial lining. The latter contain multiple vesicles, which may fuse in order to form transcytoplasmic channels. Sphincter-like muscle bundles at the transition points from capillaries to venules may provide hemodynamic regulatory structures in the submucosa of the horse. Veins with circumferential cushions of smooth muscle fibres, so-called 'throttle veins', are also found.

Effects of hemodilution on splanchnic perfusion and hepatorenal function. I. Splanchnic perfusion

Perfusion of intestinal organs increases in response to acute normovolemic hemodilution (ANH). However, detailed studies on distribution of regional splanchnic organ perfusion during ANH are lacking. We therefore carried out this study to test the hypothesis that ANH does not cause disturbance of physiologic patterns of regional splanchnic organ blood flow. After governmental permission, 22 anesthetized dogs were instrumented to allow invasive hemodynamic measurements and intracardial injection of radioactive microspheres (diameter 15 micro m) for determination of regional organ perfusion. Measurements were made at baseline (hematocrit 37 +/- 3%) and after ANH with 6% hydroxyethyl starch (mol. wt. 200000 / 0.5) to hct 20 +/- 1%. After completion of the protocol, splanchnic organs were removed and dissected into small samples according to anatomical and functional principles. Regional perfusion was determined based on the microsphere content of each sample. Hepatic, intestinal, and pancreatic blood flow increased with ANH. Hepatic arterial blood flow rose by 86%, whereas portal venous perfusion increased by 28%. Small intestine mucosal perfusion was augmented by 68% while the non-mucosal tissue compartment of the gut wall received 32% more blood flow after ANH which is in proportion to the increase in cardiac index after ANH. This redistribution of intestinal flow might be the basis for the preservation of tissue oxygenation during moderate isovolemic anemia.

[Intramural vascular system of the large intestine of mammals. A study of the literature]

From a morphological point of view, too, the summarizing synopsis of the intramural vascular system of the large intestine of mammals shows, that the functional aspect is prominent. As in other studied species the exclusively on the epithelial side existing 'fenestrated endothelium' of the pericryptal and subepithelial capillaries is doubtless the most important structural mark of the large intestinal function, too. Moreover, the direction of the mucosal capillary blood flow informs, that at first the release of the essential substances for the glandular secretion will take place, before epithelial transports concerning the resorption occur. As for the hemodynamic regulatory structures in the wall of the blood-vessels there are obviously differences in their existence depending on the species, respectively they are completely absent such as in the ruminants. Finally, it should be mentioned, that arterio-venous anastomoses could not be detected.

Large intestinal lymphocytic phlebitis and venulitis in chronic ulcerative colitis

Colonic vasculitis is seen in Crohn's disease and as a component of primary systemic vasculitis. It has rarely been described in chronic ulcerative colitis. Here we report a case of ulcerative colitis with prominent transmural lymphocytic phlebitis and venulitis. Although this is, to our knowledge, the first description of such an association, its recognition is important if confusion with other entities is to be avoided. The etiology of the vascular changes is unclear but they may be a secondary phenomenon induced by antigens, toxins or cytokines draining from the inflamed mucosa.

[Reconstructive plastic surgery of the esophagus in children]

The article presents the authors' experiences with reconstructive-plastic operations of the esophagus in children. The esophagoplasty was performed in 60 patients with congenital and acquired diseases. Among the congenital diseases are esophageal atresia, short esophagus and Barrett's esophagus, the acquired diseases include postburn scarry injuries. The optimum method of creation of the artificial esophagus are described. Of great significance are thought to be angiosurgical and microsurgical methods of cutting out the intestinal transplants. Cases of free autotransplantation of the intestinal segments for the substitution of the injured esophagus are described. Positive results were obtained in most cases.

Results of portal thrombectomy and splanchnic thrombolysis for the surgical management of acute mesentericoportal thrombosis

BACKGROUND

Acute venous mesenteric ischaemia is rare and there is no standard conservative or operative treatment.

METHODS

The results of surgical treatment for acute mesentericoportal thrombosis were retrospectively analysed in 31 patients. The thrombotic occlusion affected the superior mesenteric vein in 19 patients, the portal vein in eight and both vessels in four. Surgical treatment comprised venous thrombectomy (nine patients), bowel resection (17), a combination of thrombectomy and bowel resection (two), distal splenorenal shunt (one) and simple laparotomy (two).

RESULTS

When the mesentericoportal blood flow was restored, the mortality rate was lower, but not significantly so, than after bowel resection alone (two of nine versus seven of 17). In addition to thrombectomy, local thrombolysis with recombinant tissue plasminogen activator was performed in five patients via a catheter placed into a distal mesenteric vein and all survived. The overall hospital mortality rate was 11 (35 per cent) of 31.

CONCLUSION

An active approach should be encouraged in patients with this condition employing thrombectomy in addition to bowel resection. Early results are encouraging and local thrombolysis warrants further study.

Immunocytochemical expression of the 70 kD heat shock protein in ischaemic bowel disease

Heat shock proteins (HSPs) are a family of polypeptides which are induced in response to diverse forms of cell injury including hyperthermia, anoxia, ethanol, heavy metals, and others, with a presumably protective function. Among several species of HSPs, the 70 kD protein (HSP70) is the most abundant and consistently induced in mammalian cells. Anti-HSP70 monoclonal antibody and a standard immunocytochemical method were used to study the expression of HSP70 in 28 surgical specimens of small and large intestines from patients with ischaemic bowel disease. Strong immunoreactivity was observed in viable, regenerating cells of both the crypt and surface epithelium within or adjacent to the necrotic foci in 86 per cent of the ischaemic bowel specimens. Staining was mostly cytoplasmic, but focally both cytoplasmic and nuclear. Smooth muscle cells of the muscularis mucosae in the ischaemic areas of some cases also showed immunoreactivity. On the other hand, HSP70 was not expressed in control specimens of small and large intestine or in colonic specimens of Crohn's disease, ulcerative colitis, and adenocarcinoma. These findings suggest a possible role of HSP70 in intestinal epithelial and smooth muscle cell response to ischaemic injury, especially in the recovery phase.

Alveolar hydatid cyst (AHC): inflammation-induced reactive gastrointestinal (GL) amyloidosis in AHC-infected mice and chemical characterization of the GL amyloid

A high incidence of GI amyloidosis has been described in patients with various forms of systemic amyloidosis but its evolution and progression in different subregions of the GI tract are not well documented. These aspects including the chemical nature of GI amyloid were examined in the AHC mouse model of inflammation-associated reactive amyloidosis. C57BL/6 mice were infected intraperitoneally with 250 AHC. Paraffin sections from the stomach and the small and large intestines of AHC mice were stained at different time intervals with Congo red or immunocytochemically with monospecific RAA. The submucosal blood vessels at 1 week postinfection were found to be the first target of amyloid deposition. With time the amyloid deposits extended to the mucosa and the Peyer's patches and immunoreacted with RAA; ileum was the most severely affected region. Amyloid was extracted from the GI tract and purified by size exclusion chromatography using 5 M guanidine-formic acid, pH 3. The purified amyloid was identified by Western blotting using RAA and by partial N-terminal microsequencing up to 10 cycles. The GI amyloid showed homology with murine SAA2, although SAA2 mRNA is not expressed in murine GI tract. These results shows that (a) the GI amyloid is derived, similar to that of splenic/hepatic amyloid, from circulating SAA2 and (b) the GI tract submucosal blood vessels are the first target of AA deposition. The data also suggest that AA-mediated damage to the submucosal blood capillaries may lead to SAA leakage followed by cascading of AA deposition in other layers of the GI tract.

[Vascular system in the large intestine of the dog (Canis lupus f. familiaris)]

The vascular system of the large intestine of 10 dogs was examined by means of vascular corrosion casts, histology and transmission-electron microscopy. The tela submucosa contains an arterial and a venous vascular plexus. In broader areas of the submucosa, a deep and a superficial vascular plexus, which are interconnected, can be found. The plexus are orientated parallel to the layers of the intestinal wall. On the one hand, these vessels naturally provide self-sufficiency and drainage of the submucosa, and, moreover, direct branches to the stratum circulare of the muscular layer. On the other hand, the submucosal vascular plexus is the 'distributional network' for the functional plexus of the tunica mucosa. The arteries, which ascend to the tunica mucosa, supply a flat arterial network underneath the intestinal glands. Bundles of only a few arteriolae originate from this in order to supply the pericryptal capillaries. In the vicinity of the cryptal orifices, these turn into a network of subepithelial capillaries, which is post-connected to the periglandular capillary plexus. From this 'terminal circulatory pathway', the blood is drained off by veins that enter the submucosal plexus. It is characteristic that the postcapillary venules often begin as part of the capillary network. As in other species, the subepithelial capillaries are pre-dominantly lined with a 'fenestrated endothelium', whereas the capillaries of the pericryptal areas show a continuous endothelium. The latter contains multiple vesicles that may fuse in order to form transcytoplasmic channels as a morphological equivalent for transcappillar-epithelial and vice versa occurring transport of substances.

[The blood vessel system of the large intestine of swine (Sus scrofa f. domestica)]

The circulatory system of the large intestine of 27 pigs was examined by means of corrosion anatomy (vascular casts), histology and electron microscopy. The results were as follows: The Aa. et Vv. breves et longae leave the mesenteric vessels and reach the wall of the intestine at the mesenteric margin. The short vessels enter the deeper layers of the wall, whereas the Aa. et Vv. longae, by taking a variable subserous course, reach the submucosa after penetrating the muscular layers. The tela submucosa contains an arterial and a venous vascular plexus. Where the submucosa is larger, there is a three-dimensional vascular network, a deep and superficial vascular plexus that are closely interconnected. The deep plexus is applied to the inner circular muscles, whereas the superficial plexus is adjacent to the muscularis mucosae. The deep arterial plexus receives its afflux from the Aa. breves et longae and provides part of the circular muscle layers with recurrent muscle branches. The vascularization of the mucosa is derived from the (superficial) submucosal plexus. The arteries that ascend the tunica mucosa ramify, in the form of a brush, into some arterioles. In the basal part of the mucosa, they turn into a periglandular capillary system, i.e. a network around each Lieberkühn crypt. Close to the lumen, a polygonal subepithelial capillary system is formed. Below the epithelium of the mucosal surface, the capillaries turn into postcapillary venules. These are running vertically through the submucosa, with few inflowing side branches, and finally enter the submucosal plexus An intermuscular plexus is formed by anastomoses between the circular and the longitudinal muscular layers from the branches of the subserous-submucosal connections. This intermuscular plexus provides the capillaries for the tunica muscularis. The subepithelial capillaries are, above all, furnished with a so-called fenestrated endothelium, whereas the capillaries of the pericryptal mucosa mainly show a continuous endothelium. The latter contains multiple vesicles that can fuse to form transcytoplasmic channels. In the wall of the large intestine of the pig, there are no sure indications as to the existence of either arterio-venous anastomoses or haemodynamic regulatory structures.

[Intramural blood vessel system of the large intestine of domestic ruminants]

The vascular system of the large intestine of 15 cattle, 10 sheep and 5 goats has been examined by means of corrosion vascular casts, histology and electron microscopy. The results are as follows: The course and ramification of the intestinal vessels are identical in the caecum, colon and rectum. Furthermore, as expected, amongst the species studied no substantial differences in the vascular architecture of the large intestinal wall could be determined. The extramural vessels reach the wall of the intestine at the mesenteric margin. Their branches build arterial or venous networks in the tela subserosa, which then divide into branches in the direction of the antimesenteric region. The connections between the blood vessels of the tela subserosa and the tela submucosa as well as the branches to the muscular layers emerge from these networks. In the tela submucosa an arterial and venous system can be found. The obvious vascular arrangement in the submucosa is arranged not only parallel to the stratum circulare of the tunica muscularis but also along the prevailing direction of the lamina muscularis mucosae. From this arrangement both a deep and a superficial submucosal vascular plexus can be denominated. The recurrent branches for the circular muscle layer as well as the afferent and efferent vessels of the mucosa originate from submucosal arteries and veins. The arterioles of the tunica mucosa branch at the level of the basal crypts into a periglandular capillary system running close to the lumen into a subepithelial capillary system. Here the capillaries drain into venules which advance to the region of the intestinal glands and consequently drain into collecting veins in the submucosa. Capillaries of the subepithelial lamina propria mucosae are furnished with continuous or fenestrated endothelial linings as the morphological equivalent of the secretory or resorption processes, respectively. In the walls of the large intestine of the bovine, sheep and goat there are neither arterio-venous anastomoses nor hemodynamic regulatory structures such as sphincters or so-called throttle veins at the points of transition from capillaries to venules. These results are in accord with the findings in the small intestine of domestic ruminants (Hummel 1980).

[Nonobstructive intestinal ischemia]

Acute or chronic intestinal ischaemia can be the consequence of either intrinsic vascular disease, systemic disease, drugs or surgical procedures. In one quarter of the patients with intestinal ischemia, no major vascular obstructions can be detected. Very rarely, the cause of ischaemia is splanchnic vasoconstriction due to cardiac arrhythmias or sepsis. The bowel becomes ischaemic as a result of underperfusion. The clinical picture resembles the one of occlusive intestinal ischaemia. From the pathological standpoint, the ischaemia is more intense on the antimesenteric border of the bowel and the lesions are more advanced in the mucosal than in the serosal layer. Often, the ischaemia involves other organs too: liver, spleen or gallbladder. The reconstructive vascular procedures are inefficient, the only therapeutical options remains the resection of the infarcted bowel, together with other organs involved in the ischaemic process. The mortality rate approaches 90%.