Vascular patterns of small and large intestine compared

Diverticular hemorrhage of terminal ileum successfully treated by ultra-selective transcatheter arterial embolization using triaxial system: a case report

Small intestinal hemorrhage due to diverticulum is a relatively rare condition among gastrointestinal hemorrhages. We report a case of diverticular hemorrhage of the terminal ileum that was successfully treated by ultra-selective transcatheter arterial embolization using a triaxial system. A 25-year-old man was referred to our hospital due to melena. Abdominal contrast-enhanced computed tomography demonstrated marked extravasation of contrast medium in a diverticulum of the terminal ileum. We immediately attempted transcatheter arterial embolization after onset of hemorrhagic hypovolemic shock. Angiogram of the superior mesenteric artery revealed apparent hemorrhage at the end of the ileocolic artery. We performed embolization with 2 platinum coils using a triaxial system via the vasa recta of the terminal ileum. This procedure stopped extravasation of contrast medium. Postoperative course was uneventful, and he was discharged four days postoperatively. The triaxial system may facilitate high diagnostic ability to accurately identify target arteries of the ileal diverticular hemorrhage.

Special considerations in the management of lower GI bleed by interventional radiology

Despite the rapid development of diagnostic and therapeutic modalities and techniques to manage LGIB patients from interventional radiology's standpoint, a successful localization of the bleeding site that leads to an effective embolotherapy remains a significant technical challenge. The interventional radiologist's decisions when managing patients with LGIB may significantly impact the clinical outcomes; therefore, management should be made based on careful and thorough considerations of factors such as etiology, locations, patient's comorbidities, and potential post-procedure complications, among others. The purpose of this paper is to review the management of LGIB by interventional radiology, focusing on a few challenging and common clinical situations that require special consideration by interventional radiologists.

The superior mesenteric artery and the variations of the colic patterns. A new anatomical and radiological classification of the colic arteries

The superior mesenteric artery (SMA) supplies irrigation to the small intestine, ascending and a variable area of the transverse colon. Although medical imaging and surgical procedures have been widely developed in the last decades, the anatomy of the SMA using advanced imaging technology remains to be elucidated. Previous studies have used small sample sizes of cadaveric or radiological samples to propose a number of classifications for the SMA. In this study, we aimed to provide a more detailed description and useful classification of the SMA and its main branches [middle colic artery (MCA), right colic artery (RCA), and ileocolic artery (ICA)]. Samples (n = 50, 28 males and 22 females) were obtained from the repository of human cadavers located at the Department of Human Anatomy and Embryology, Complutense University of Madrid. This sample was dissected by preclinical medical students and completed by two of the authors (Gamo and Jiménez). A second set of samples was obtained from a bank of computerized tomography (CT) (560 CTs, 399 males and 161 females) collected by the Radiology Department at the Clínico San Carlos Hospital, Spain. Based on the results obtained from these studies, we propose a new classification of four patterns for the SMA anatomy. Pattern I as the independent origin of the three main branches of the SMA (cadaveric 40 %; CT 73.69 %); Pattern II is subdivided in three sub-patterns based on the common trunks of origin: Pattern IIa, common trunk between RCA and MCA (cadaveric 20 %, CT 4.28 %); Pattern IIb, common trunk between RCA and ICA (cadaveric 32 %, CT 15 %); Pattern IIc, common trunk for the three main branches (cadaveric 0 %, CT 0.35 %); Pattern III, as the absence of RCA (cadaveric 8 %; CT 2.32 %) and Pattern IV, based on presence of accessory arteries (not found in any of the samples). Although the independent origin of the three colic arteries have been classically described as the most frequent, the right colic artery is responsible of major variations.

The angiographic anatomy of the small arteries and their collaterals in colorectal resections: some insights into anastomotic perfusion

OBJECTIVE

The aim of this study was to examine by screening angiography the anatomy of the small arteries and their collaterals in colorectal resections in order to identify factors that might be implicated in anastomotic leak.

SUMMARY BACKGROUND DATA

Anastomotic leak is more frequent following low anterior resection. Vascular compromise is frequently implicated but poorly understood as a mechanism.

METHODS

High definition screening angiography was performed on 17 colorectal resection specimens.

RESULTS

(1) The small arteries of the colon (the vasa recta that arise from the marginal artery) show variability in their spacing and in their collaterals based on their anatomical positions. At the splenic flexure and the proximal and mid descending colons, the vasa recta are spaced 2-cm apart and have few collaterals. At the right, transverse, distal descending and sigmoid colons, the vasa recta are spaced <1 cm apart and have more extensive collaterals. (2) The small arteries of the rectum are spaced <1 cm apart and also show variability in their collaterals based on their anatomical level. In the mid-to-upper rectum there are good collaterals between the small arteries within the mesorectum based upon the bifurcation of the superior rectal artery and its main branches. In the lower rectum, however, there are only a few and very variable intramural collaterals between the small arteries.

CONCLUSIONS

Based on these findings, unrecognized disruption of small artery collaterals during colorectal resection might be implicated in anastomotic leak and in particular might explain the higher leak rate in low anterior resection.

Ischemic effects of transcatheter arterial embolization with N-butyl cyanoacrylate-lipiodol on the colon in a Swine model

This study was designed to assess the safety of transcatheter arterial embolization (TAE) with n-butyl cyanoacrylate-lipiodol (NBCA-Lp) for the large bowel and to investigate the vital response to NBCA-Lp in a swine model. In nine swine, nine arteries nourishing the colon were embolized with NBCA-Lp (1 ml of NBCA mixed with 4 ml of lipiodol): sigmoid-rectal branch artery in six swine, right colic branch artery in two, and middle colic branch artery in one. The amount of NBCA-Lp was 0.1-0.4 ml. Sacrifice was conducted 3 days after TAE to identify histological infarction. Classification was conducted retrospectively: group A, vasa recta without NBCA-Lp embolization despite TAE; group B, three or fewer vasa recta with NBCA-Lp embolization; and group C, five or more vasa recta with NBCA-Lp embolization. In one swine in group A, no necrotic focus was observed. In group B, three of four swine experienced no ischemic damage. The remaining one swine experienced necrosis of mucosal and submucosal layers in one-fourth of the circumference. In group C, all four swine with marginal artery and five vasa recta or more embolized experienced total necrosis of mucosa, submucosa, and smooth muscle layers of the whole colonic circumference. Significant difference on the extent of ischemic damage was observed between groups B and C (P < 0.05). Microscopically, NBCA-Lp induced acute vasculitis. Embolization of three or fewer vasa recta with NBCA-Lp induced no ischemic damage or limited necrosis, whereas embolization of five or more vasa recta with NBCA-Lp induced extensive necrosis.

Transcatheter treatment for lower gastrointestinal hemorrhage

Modern transcatheter embolization has emerged as a viable option for the treatment of lower gastrointestinal (LGI) hemorrhage. Over the last decade, steady data has accumulated showing the safety and effectiveness of superselective microcoil embolization within the colon. In light of such results, the application of microcatheter-based skills has become more important in an algorithm for managing LGI bleeding. The purpose of this article is to discuss the modern embolization technique while also reviewing traditional and experimental transcatheter methods that may prove useful in the appropriate clinical settings. While recognizing that transcatheter therapy continues to evolve, the proposed indications for these current treatments are reviewed.

Superselective microcoil embolization for the treatment of lower gastrointestinal hemorrhage

PURPOSE

To evaluate the safety and effectiveness of superselective microcoil embolization for the treatment of lower gastrointestinal (LGI) hemorrhage.

MATERIALS AND METHODS

A retrospective review of LGI superselective microcoil embolization data for a 10-year period was performed. During this period, twenty-two patients with evidence on angiography of LGI bleeding underwent superselective microcoil embolization. Hemorrhage was treated in the colon (n = 19) and jejunum (n = 3). Ivalon was used adjunctively in two patients and gelfoam was used as a secondary agent in two additional patients. Postembolization ischemia was evaluated objectively in 14 patients by colonoscopy (n = 10), surgical specimen (n = 3), and barium enema (n = 1). All patients were followed for clinical evidence of bowel ischemia. Four patients died before further follow-up could be performed. Additionally, 122 cases of LGI hemorrhage treated with superselective microcoil embolization were identified in a review of the literature. A meta-analysis was then performed, combining the data in this study and the data from the literature, to estimate the rate of major and minor ischemic complications on a total of 144 superselective microcoil embolizations.

RESULTS

Immediate hemostasis was achieved in all 22 patients in this study. Complete clinical success was achieved in 86% of patients (19 of 22 patients). Rebleeding occurred in 14% of patients (3 of 22 patients) and each underwent colonoscopic intervention with success. Postembolization objective follow-up was performed in 64% of patients (14 of 22 patients). Ten patients underwent follow-up colonoscopy; one patient received a follow-up barium enema; and three patients underwent subsequent surgery. Colonic resection (one partial and one total) was performed in two patients. The partial colectomy was performed in a patient who had been diagnosed with colonic polyps and dysplasia. The total colectomy was performed on a patient with history of chronic LGI bleeding complicated by long-term anticoagulation therapy and a history of tubular adenoma resection. The third surgical patient (16 months old) underwent a follow-up exploratory laparotomy after embolization of a proximal jejunal branch of the superior mesenteric artery. None of the three patients who underwent surgery were found to have postembolic ischemic changes in the bowel specimen. Four patients in this study died, for reasons unrelated to hemorrhage or embolization, before further follow-up could be performed. The last four patients were followed clinically and experienced no symptoms of intestinal ischemia. A minor ischemic complication was reported in 4.5% of patients (1 of 22 patients), and there were no major ischemic complications (0%) in this series. A review of the data from 122 cases of LGI superselective microcoil embolization in the literature is also presented. Combined with the data in this study, the minor complication rate was 9% (13 of 144 patients), and the major complication rate was 0% (0 of 144 patients).

CONCLUSION

Superselective microcoil embolization is a safe and effective treatment for LGI hemorrhage.

Morphologic and histopathologic changes in the bowel after super-selective transcatheter embolization for focal lower gastrointestinal hemorrhage

PURPOSE

To evaluate the safety of superselective arterial embolization therapy in the lower gastrointestinal tract. The sequelae on normal enteric tissue in lower gastrointestinal arterial embolization were retrospectively reviewed.

MATERIAL AND METHODS

To control hemorrhage and tumor blood supply, 14 patients were treated by superselective transcatheter embolization at different levels of the colonic and small intestine vessels via the superior and inferior mesenteric arteries using microcoils and/or gelatin sponge. Normal enteric tissues in the embolized areas were analyzed for the occurrence of ischemic changes by clinical follow-up, colonoscopy, and surgery.

RESULTS

Normal bowel function was preserved in 13 patients. In 1 patient treated with numerous gelatin sponge particles delivered from the proximal arcade of the superior mesenteric artery, significant muscular fibrosis occurred.

CONCLUSION

Superselective arterial embolization for lower gastrointestinal hemorrhage can be safely performed by minimizing the amount of embolic materials and delivering them as distally as possible.

Treatment of lower gastrointestinal bleeding: vasopressin infusion versus embolization

Traditionally, embolization has been reserved for treatment of upper gastrointestinal bleeding whereas lower gastrointestinal (LGI) bleeding has been controlled with vasopressin infusion. This is based on findings in older literature in which infarction frequently complicated LGI embolization. With modern embolization techniques, clinically significant bowel ischemia has become an uncommon complication. Although the efficacies of vasopressin and embolization are fairly comparable, embolotherapy has advantages in terms of quicker completion of therapy and decreased likelihood of systemic complications. Although vasopressin is still probably preferable for diffuse lesions and cases in which superselective catheterization is not technically possible, embolization should be considered a primary option for treating LGI bleeding.

Transcatheter embolization for acute lower gastrointestinal hemorrhage

PURPOSE

The authors review their experience using transcatheter embolization in the treatment of acute lower gastrointestinal hemorrhage.

MATERIALS AND METHODS

A retrospective review was conducted on 17 patients who underwent superselective transcatheter embolization for an acute lower gastrointestinal hemorrhage. All 17 patients were followed clinically 4 days to 60 months (mean, 18.5 months) after embolization for the presence of ischemia or for recurrent bleeding. In addition, 12 of 17 patients were examined 1 day to 12 months (mean, 38.8 months) after embolization by means of colonoscopy or by pathologic review.

RESULTS

Transcatheter embolization achieved immediate hemostasis in 15 of 17 patients (88%) and was the definitive treatment in 76%. The other two patients underwent successful surgical resections after incomplete hemostasis of cecal lesions. Two patients of the 15, with initially successful embolizations, had recurrent hemorrhage within 30 days; both underwent further embolization with one failure. No intestinal infarction or stricture developed in the 15 patients who underwent successful embolization.

CONCLUSIONS

The authors' experience supports the role of transcatheter embolization as a primary means of therapy for patients with an acute lower gastrointestinal hemorrhage. Their data further supports growing evidence that superselective embolization may be most efficacious in reducing complication rates.

Imaging and radiological interventional techniques for gastrointestinal bleeding in children

Causes of pediatric gastrointestinal (GI) bleeding in children are numerous. The role of radiology in defining associated pathology, pinpointing the bleeding site, and intervening to control hemorrhage is discussed here. Barium studies, computed tomography (CT), and magnetic resonance imaging (MRI) each may play a role in identifying the underlying pathology associated with the bleeding. The exact source of bleeding may be localized by means of nuclear scintigraphy as well as selective angiography. In cases of life-threatening or persistent hemorrhage, once a bleeding source is identified, the interventional radiologist may offer percutaneous transcatheter therapy with selective intraarterial vasopressin infusion or embolotherapy.

Embolization of superior mesenteric artery branches in dogs. Ischemic bowel changes depend on location of vessel occlusion and embolic materials

OBJECTIVE

To evaluate the degree of ischemic changes of the small intestine after arterial embolization of proximal or distal arteries with Gelfoam particles and coils in dogs.

METHODS

Superselective arterial embolization in 18 dogs was performed using a coaxial catheter system. Gelfoam occlusion of the proximal level of ileal or jejunal arteries was performed in four dogs (group A). Gelfoam occlusion of the distal level was performed in four dogs (group B). Coil occlusion of the proximal level was performed in five dogs (group C). Coil occlusion of the distal level was performed in five dogs (group D). All 18 dogs were killed 1 day after the procedure. Gross and microscopic findings were evaluated.

RESULTS

The embolizations were successful in all dogs. In group B, significant mucosal destruction, lymphocyte proliferation of the submucosa and mucosa, and diffuse swelling in all layers of the intestine were found in all four dogs. Three revealed diffuse ischemic changes and one showed focal ischemic changes. In groups A and C, all the layers of the intestine were intact and did not show any ischemic changes. In group D, one dog showed erosion of a small portion of mucosa and lymphocytic infiltration. The other dogs showed nonspecific findings in all layers of the intestine.

CONCLUSIONS

Proximal embolization with Gelfoam and coils as well as distal embolization with coils did not cause ischemia. However, ischemic changes in the intestinal wall could be observed after distal embolization with Gelfoam.

Embolization of the vasa recta in acute lower gastrointestinal hemorrhage: A report of five cases

PURPOSE

To present our preliminary experience in embolization of the vasa recta in acute gastrointestinal hemorrhage.

METHODS

In four of five patients with acute gastrointestinal hemorrhage superselective embolization of the vasa recta was performed. In one patient in whom superselective catheterization of the bleeding vas rectum was technically impossible, the origin of this vessel was embolized at the level of the terminal arcade. The following embolization materials were used: microcoils and polyvinyl alcohol particles (355-500 microm), n = 2; microcoils only, n = 2; Gelfoam particles, n = 1.

RESULTS

Bleeding was found in two patients in the small bowel (jejunum and ileum) and in three patients in the colon. Immediate hemostasis was achieved in all patients. No signs of ischemia or infarction were observed after intervention.

CONCLUSIONS

Superselective embolization of the vasa recta proved efficient and safe in our small patient group. Advantages of this technique are reduction of the embolized area to a minimum and direct control of hemostasis.

Percutaneous embolotherapy of lower gastrointestinal hemorrhage

PURPOSE

To evaluate percutaneous embolotherapy in the treatment of lower gastrointestinal hemorrhage.

MATERIALS AND METHODS

Twenty-one patients who underwent attempted percutaneous embolization for acute lower gastrointestinal bleeding between 1982 and 1997 were retrospectively studied. Hemorrhagic sites included jejunum (n = 4), ileum (n = 4), cecum (n = 4), and the remaining colon (n = 9).

RESULTS

Embolization was not technically possible in four patients (19%). Hemostasis was achieved in 15 patients (71%) with prolonged hemostasis in 10 (48%). All embolizations distal to the cecum resulted in prolonged hemostasis. Three of four patients with jejunal bleeding had recurrent bleeding after apparent successful embolization. Only one of four cecal embolizations achieved prolonged cessation of bleeding. No ischemic complications were identified.

CONCLUSION

Based on these data, it would appear that the risk of bowel ischemia/infarction in the lower gastrointestinal tract may not be as high as has been suggested. Two regions (cecum and proximal jejunum) were associated with poor results, suggesting these areas may not be as responsive to embolotherapy as other sites in the lower gastrointestinal tract.

Superselective coil embolization in acute gastrointestinal hemorrhage: personal experience in 10 patients and review of the literature

PURPOSE

To evaluate the safety and efficiency of microcoil embolization in upper and lower gastrointestinal hemorrhage.

PATIENTS AND METHODS

Superselective microcoil embolization was performed in 10 patients (upper gastrointestinal bleeding, n = 3; lower gastrointestinal bleeding, n = 7) who had acute gastrointestinal hemorrhage. Embolization was performed as peripherally as possible with use of coaxial catheter systems. Embolization materials included microcoils (2-4 mm) alone (n = 5), microcoils and polyvinyl alcohol particles (355-500 microm) (n = 4), and microcoils and gelatin sponge particles (n = 1).

RESULTS

Immediate hemostasis was achieved in eight patients. In two patients with dual blood supply of the bleeding site, significant reduction of hemorrhage resulted. In these two patients, it was technically impossible to place the coaxial catheter distally enough to allow safe embolization of both feeding vessels. No clinical signs of ischemia or infarction were observed after intervention.

CONCLUSION

Microcoil embolization is a safe and efficient procedure for controlling acute lower gastrointestinal bleeding if performed in a superselective catheter position. In upper gastrointestinal bleeding, microcoil embolization is an established treatment and can be performed more proximally.

[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.

Emergent embolotherapy of small intestine hemorrhage

The efficacy of emergent embolotherapy was evaluated in six patients suffering hemorrhage from the small intestine. Hemorrhage was from the jejunum in four patients, from the ileum in one, and from Meckel's diverticulum in one. Superselective embolization of the arcade of the small intestine artery branch was performed in all patients with a coaxial catheter. Embolic materials used were Gelfoam particles alone or Gelfoam particles plus coils in earlier cases and microcoils in recent cases. Complete hemostasis was immediately achieved in all patients, but one patient died of disseminated intravascular coagulation. After stabilization of the patient's condition by hemostasis, elective surgery was performed on three patients suffering small intestine ulcer. Histopathologically, no bowel infarction was noted but mild mucosal inflammation with submucosal edema was found in the jejunum of two patients. We recommend embolization for life-threatening small intestine hemorrhage, preferentially in situations where the blood vessel involved can be super-selectively occluded at the nearest level of the arcade of the vasa recta, lest the vasa recta should be occluded.

Transanal and intraperitoneal prolapse in intussusception

An infant with intussusception who developed an unusual complication of transanal and intraperitoneal prolapse is reported. Complete venous occlusion of the intussusceptum for a prolonged period in a patient with congenital anomalous vascular supply of the colon is suggested as a mechanism responsible for rupture of the intussuscepiens.

Embolisation in small bowel haemorrhage

As embolism of small bowel arteries carries the risk of bowel infarction, the technique is usually reserved for situations where a vasopressin infusion has failed to control bleeding. We report three cases in which embolisation was used as the primary treatment to control small bowel haemorrhage without the complication of bowel infarction.

A new surgical approach to duplications of the intestine

Two unusual intestinal duplications are described. In each case the mesenteric duplication had a separate muscular coat from the normal bowel permitting complete excision of the duplication without interference with the blood supply to the normal intestine.

Per catheter control of haemorrhage from the superior and inferior mesenteric arteries

The relevant findings in 11 cases of per catheter control of haemorrhage from different sites in the large and small bowel are presented together with a description of the techniques and some of the possible complications of vasopressin infusion and gelfoam embolisation. In six of these cases vasopressin infusion was sus achieved by embolisation, three following the failure of vasopressin therapy. In one case embolisation of the ileo-colic artery produced a caecal infarct. Important differences in the vascular supply to the large and small bowel and their practical significance in embolisation are discussed.

Experimental gut anastomoses and their revascularization

A study was made of the healing and revascularization of intestinal anastomoses in the small and large intestines of rabbits. Single-layer and double-layer suture, techniques were used and compared, and revascularization of the anastomoses was particularly examined after devascularization of their distal segments. The anastomotic segments were removed at intervals after construction varying from one to six weeks and studied histologically after haemotoxylin and eosin staining, by xylol-clear thick sections and by angiography, a gelatin Micropaque emulsion being used to fill the vascular network. Forty-four rabbit intestinal anastomoses were studied. Inverted intestinal anastomoses took about two weeks to develop continuous mucosa on the luminal side, and were completely healed after six weeks. Revascularization began after eight days with both single-layer and double-layer anastomoses, proceeding from the submucosal and the surrounding muscular layers. The vascular pattern mirrored the healing stage of the anastomosis. Irregular fine vessels crossing the anastomoses were seen in specimens examined at the second week. After three or four weeks, the vascular patterns of the anastomoses showed an irregularity of calibre and direction because of the presence of residual scar tissue, and the mucosal surfaces were covered with regenerating epithelium. Healing and revascularization were complete after six weeks.