PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “MESENTERIC VESSELS”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,747 records · Page 97Linked to original sources

Interstitial cells in the vasculature.

Interstitial cells of Cajal are believed to play an important role in gastrointestinal tissues by generating and propagating electrical slow waves to gastrointestinal muscles and/or mediating signals from the enteric nervous system. Recently cells with similar morphological characteristics have been found in the wall of blood vessels such as rabbit portal vein and guinea pig mesenteric artery. These non-contractile cells are characterised by the presence of numerous processes and were easily detected in the wall of the rabbit portal vein by staining with methylene blue or by antibodies to the marker of Interstitial Cells of Cajal c-kit. These vascular cells have been termed "interstitial cells" by analogy with interstitial cells found in the gastrointestinal tract. Freshly dispersed interstitial cells from rabbit portal vein and guinea pig mesenteric artery displayed various Ca2+-release events from endo/sarcoplasmic reticulum including fast localised Ca2+ transients (Ca2+ sparks) and longer and slower Ca2+ events. Single interstitial cells from the rabbit portal vein, which is a spontaneously active vessel, also demonstrated rhythmical Ca2+ oscillations associated with membrane depolarisations, which suggests that in this vessel interstitial cells may act as pacemakers for smooth muscle cells. The function of interstitial cells from the mesenteric arteries is yet unknown. This article reviews some of the recent findings regarding interstitial cells from blood vessels obtained by our laboratory using electron microscopy, immunohistochemistry, tight-seal patch-clamp recording, and fluorescence confocal imaging techniques.

Animals↗

P-selectin knockout: a mouse model for various human diseases.

P-selectin is a transmembrane adhesion receptor specific to platelets and endothelial cells. It has an N-terminal lectin domain that recognizes specific carbohydrate moieties on monocytes, neutrophils and some other subsets of leukocytes. P-selectin is stored in granules and is expressed on the plasma membrane only after the cells are stimulated by vascular injury or during inflammation. Physiologically P-selectin is likely to be involved in the recruitment of leukocytes that promote wound healing and fight infection. There are many disorders in which the excessive recruitment of leukocytes is characteristic, including chronic inflammation, atherosclerosis, arthritis, diabetes, asthma and reperfusion injury. Because certain cancer cells also express the ligand for P-selectin it is possible that this receptor is involved in metastasis. To study the specific role of P-selectin in these pathological processes, we have prepared a mouse lacking P-selectin through gene targeting. Leukocyte interaction with the vessel wall is defective in these animals as leukocytes do not roll in the mesenteric venules and their extravasation at sites of inflammation and vessel injury is limited. We are testing these animals in models of the various diseases mentioned above in order to evaluate when the absence of P-selectin is beneficial.

Animals↗

Subendothelial nerve fibers in bovine mesenteric lymphatics: an ultrastructural and immunohistochemical study.

In the lymphatic vessels of man and most animals the nerve fibers are confined to the adventitia. However, immunohistochemical studies suggest that acetylcholinesterase-positive and monoamine-containing fibers reach as far as the endothelium in bovines. The aim of this study was to verify the presence of subendothelial nerve fibers by transmission electron microscopy (TEM) in bovine mesenteric lymphatics and to determine whether typical sensory neurotransmitters such as Substance P (SP) and calcitonin gene related peptide (CGRP) could be detected in these fibers. TEM revealed numerous unmyelinated nerve fibers in the subendothelial connective environment in close association with endothelial cells. Their axons were devoid of Schwann cell sheath on the endothelial side and contained small clear vesicles and large nerve fibers were demonstrated to be SP and CGRP-immunoreactive with mouse monoclonal antibodies against SP and rabbit polyclonal antibodies against CGRP. It is hypothesized that these fibers act as mechanoceptors capable of detecting intraluminal pressure and vessel wall tension variations and of locally releasing SP and CGRP. Since SP, potentiated by CGRP, is known to be a vasoconstrictor in lymphatics, we propose that the contraction of bovine mesenteric lymphatics may also be neurogenic.

Animals↗

Effects of neurotensin on norepinephrine release in blood vessels of spontaneously hypertensive rats.

The present study was performed to investigate the effects of neurotensin on noradrenergic transmission in blood vessels of hypertension. In the perfused mesenteric vasculatures prepared from spontaneously hypertensive rats (SHR) and age-matched Wistar-Kyoto (WKY) rats, we examined the influences of neurotensin on vascular responsiveness and norepinephrine release from adrenergic neurons. In studies with male standard Wistar rats, endogenous norepinephrine release during periarterial nerve stimulation was inhibited by neurotensin in a dose-dependent manner. Vasoconstrictor responses to electrical nerve stimulation were also inhibited by neurotensin. In SHR, the stimulation-evoked pressor responses and norepinephrine release were enhanced compared with WKY rats. The suppression of these responses by neurotensin was significantly less in SHR than in WKY rats. These results show that neurotensin could have a modulatory effect on noradrenergic activity and cause a decrease in stimulation-evoked norepinephrine release from vascular adrenergic neurons. The lesser reduction of pressor responses and norepinephrine release by neurotensin in SHR might suggest an insufficient regulation of vascular adrenergic transmission by the peptide hormone in hypertension.

Adrenergic Fibers↗

Experimental hypertension produces diverse changes in the regional vascular responses to endothelin-1 in the rabbit and the rat.

OBJECTIVE: To examine the effects of hypertension on systemic and regional haemodynamic responses to endothelin-1. DESIGN: Comparison of responses between age-matched control and hypertensive rabbits (two-kidney, two wrapped), and between spontaneously hypertensive rats (SHR) and control Wistar-Kyoto rats. METHODS: Arterial pressure, heart rate and blood flow responses to 0.2 nmol/kg intravenous endothelin-1 were measured in conscious animals. Blood flow was measured by pulsed ultrasound Doppler in the ascending aorta, distal abdominal aorta, left renal artery and superior mesenteric artery. RESULTS: Endothelin-1 produced qualitatively similar effects in the hypertensive and control animals. In the systemic circulation, brief initial vasodilation preceded sustained vasoconstriction. In the hindlimb, marked vasodilation preceded relatively minor vasoconstriction, and profound vasoconstriction occurred in the renal and mesenteric vascular beds. In the rats but not the rabbits, fleeting vasodilation preceded the renal and mesenteric vasoconstriction. Significant differences between hypertensive and control animals were: accentuation of the pressor effect and heart rate responses in hypertensive animals of both species, and accentuation of hindlimb vasodilation in hypertensive rabbits but not SHR; and attenuation of the depressor effect in SHR but not hypertensive rabbits, attenuation of the mesenteric vasoconstriction in both hypertensive rabbits and rats, and attenuation of renal vasoconstriction in SHR. CONCLUSIONS: The increased responses to endothelin-1 of some variables in the hypertensive animals may involve structural changes in the resistance vessels. However, the reduced responses in the mesenteric vasculature of both species and the renal vasculature of the SHR are due to some mechanism other than structural change.

Animals↗

State-of-the-art ultrasonography is as accurate as helical computed tomography and computed tomographic angiography for detecting unresectable periampullary cancer.

OBJECTIVE: To compare the ability of state-of-the-art ultrasonography with that of helical computed tomography and computed tomographic angiography in detecting unresectable periampullary cancer. In most patients periampullary cancer is unresectable because of either distant metastasis or local vascular involvement. The advent of gray scale and color Doppler ultrasonography has improved the ability of ultrasonography to detect vascular involvement. METHODS: Twenty-three consecutive patients with periampullary cancer were enrolled for prospective staging of their disease by comparing helical computed tomography and computed tomographic angiography with gray scale and color Doppler ultrasonography of the abdomen. Portal vein, superior mesenteric vein, splenic vein, and superior mesenteric artery involvement was graded 0 to 4, grade 0 being no vascular involvement and grade 4 being total occlusion of the vessel. Agreement between ultrasonography and computed tomographic angiography for determining vascular involvement was measured by chi2 analysis. RESULTS: Two patients (9%) were excluded because excessive overlying bowel gas hampered the ability of ultrasonography to visualize the pancreas. For the remaining 21 patients, there was significant agreement between ultrasonography and computed tomographic angiography for detecting vascular involvement in all vessels (P < .001; portal vein, kappa = 0.67; superior mesenteric vein, kappa = 0.67; splenic vein, kappa = 0.85; and superior mesenteric artery, kappa = 0.59). Ultrasonography was in agreement with computed tomographic angiography in all cases of unresectability. Both modalities were equally poor in preoperatively showing lymphadenopathy and metastases. CONCLUSIONS: Provided that there is adequate visualization on ultrasonography of the head of the pancreas in the periampullary region, then state-of-the-art gray scale and color Doppler ultrasonography are as accurate as helical computed tomography and computed tomographic angiography for detecting the unresectability of periampullary cancer. If performed as the initial investigation and the region of the pancreatic head is clearly shown, and if vascular encasement or occlusion or distant metastasis is identified, further investigations are unnecessary.

Adult↗

Kir2.1 encodes the inward rectifier potassium channel in rat arterial smooth muscle cells.

1. The molecular nature of the strong inward rectifier K+ channel in vascular smooth muscle was explored by using isolated cell RT-PCR, cDNA cloning and expression techniques. 2. RT-PCR of RNA from single smooth muscle cells of rat cerebral (basilar), coronary and mesenteric arteries revealed transcripts for Kir2.1. Transcripts for Kir2.2 and Kir2.3 were not found. 3. Quantitative PCR analysis revealed significant differences in transcript levels of Kir2.1 between the different vascular preparations (n = 3; P < 0.05). A two-fold difference was detected between Kir2.1 mRNA and beta-actin mRNA in coronary arteries when compared with relative levels measured in mesenteric and basilar preparations. 4. Kir2.1 was cloned from rat mesenteric vascular smooth muscle cells and expressed in Xenopus oocytes. Currents were strongly inwardly rectifying and selective for K+. 5. The effect of extracellular Ba2+, Ca2+, Mg2+ and Cs2+ ions on cloned Kir2.1 channels expressed in Xenopus oocytes was examined. Ba2+ and Cs+ block were steeply voltage dependent, whereas block by external Ca2+ and Mg2+ exhibited little voltage dependence. The apparent half-block constants and voltage dependences for Ba2+, Cs+, Ca2+ and Mg2+ were very similar for inward rectifier K+ currents from native cells and cloned Kir2.1 channels expressed in oocytes. 6. Molecular studies demonstrate that Kir2.1 is the only member of the Kir2 channel subfamily present in vascular arterial smooth muscle cells. Expression of cloned Kir2.1 in Xenopus oocytes resulted in inward rectifier K+ currents that strongly resemble those that are observed in native vascular arterial smooth muscle cells. We conclude that Kir2.1 encodes for inward rectifier K+ channels in arterial smooth muscle.

Animals↗

Leukotriene B4 mediates shear rate-dependent leukocyte adhesion in mesenteric venules.

Previous studies have demonstrated that low shear rates promote leukocyte adherence to microvascular endothelium in postcapillary venules. The objective of this study was to determine whether an accumulation of inflammatory mediators such as platelet activating factor and leukotriene B4 is responsible for shear rate-dependent leukocyte-endothelial cell adhesion. Postcapillary venules (25-39 microns in diameter) in cat mesentery were studied by intravital microscopy. Venular wall shear rate was varied over a wide range by graded occlusion of the mesenteric artery. Red blood cell velocity, vessel diameter, leukocyte rolling velocity, and the numbers of rolling and adherent leukocytes were measured at each shear rate. In one series of experiments, shear rate-dependent leukocyte adherence was monitored at different superfusion rates (1.0 and 2.5 ml/min). At the lower superfusion rate, the number of adherent leukocytes was significantly higher at any given shear rate when compared with results obtained at the higher superfusion rate. This suggests that reduced washout of inflammatory mediators contributes to shear rate-dependent leukocyte adhesion. Pretreatment with different platelet activating factor receptor antagonists (WEB 2086 or WEB 2170) had no effect on the number of adherent leukocytes normally observed at lower shear rates, suggesting that platelet activating factor does not play a major role in this process. However, shear rate-dependent leukocyte adhesion was largely prevented by pretreatment with either a leukotriene B4 receptor antagonist (SC-41930) or a leukotriene synthesis inhibitor (L663,536). The results of this study indicate that a reduced washout of leukotriene B4 is responsible for the enhanced leukocyte adherence that occurs at low venular wall shear rates.

Animals↗

Determinants of terminal mesenteric artery resistance during the first postnatal month.

Experiments were conducted to delineate the vascular effector systems that contribute to setting mesenteric vascular tone in swine during the first postnatal month. Terminal mesenteric arteries (TMA), which function as resistance vessels, were studied in vitro with a microvascular perfusion system allowing independent pressure and flow manipulation. When pressure was varied 0-100 mmHg in the absence of flow, TMA from 1-day-old animals demonstrated myogenic vasoconstriction, whereas TMA from 40-day-old animals did not. In 1- but not 40-day-old TMA, the endothelin A (ET(A)) receptor antagonist BQ-610 shifted the pressure-diameter curve upward, whereas the ET(B) receptor antagonist BQ-788 and the L-arginine analog N(G)-monomethyl-L-arginine (L-NMMA) shifted the curve downward; in all instances, myogenic vasoconstriction was preserved. Flow eliminated myogenic vasoconstriction in 1-day-old TMA, i.e., diameter increased as a function of pressure. The effect of BQ-610 was lost under flow conditions; however, BQ-788 and N-acyl-L-Trp-3,5-bis-(trifluoromethyl) benzyl ester, an antagonist specific to the substance P neurokinin-1 (NK(1)) receptor, shifted the pressure-diameter curve downward in the presence of flow, whereas L-NMMA restored myogenic vasoconstriction. Adding flow had no effect on the pressure-diameter relationship in 40-day-old TMA. Other blocking agents, including prazosin, losartan, indomethacin, and charybdotoxin, had no effect on the pressure-diameter relationship in either age group under flow or no-flow conditions. Constitutive production of nitric oxide (NO) and endothelin-1 participates in setting resistance in 1-day-old TMA, and important stimulants to NO production include flow and activation of ET(B) and NK(1) receptors. In contrast, 40-day-old TMA act as passive conduits in which the elastic properties of the vessel are the primary determinant of diameter.

Aging↗

Intra-operative monitoring of the pelvic circulation using a transanal Doppler probe.

The authors have developed a new device to examine the pre-, intra-, and postoperative pelvic blood flow, consisting of a plastic rectoscope with a commercially available 10 MHz flat Doppler probe mounted at the tip surrounded in use by a thin, acoustic gel filled condom and inserted transanally. Blood flow in the superior rectal artery can easily be detected in this way through the posterior wall of the rectum. The authors have used this technique in 70 patients, 49 undergoing abdominal aortic aneurysmectomy and 21 aorto-femoral bypass surgery. In all cases following clamping of the infrarenal aorta a synthetic bifurcated graft was anastomosed usually to the aorta using an end-to-end or end-to-side anastomosis. Immediately after application of the aortic clamp the Doppler recorder was started in order to determine the time when rectal blood flow reappeared. In the superior mesenteric artery dominant group, a good pulse wave was seen within 15 min of clamping and 88% of the aneurysm and 62% of the aorto-iliac patients fell into this group. Fourteen patients in this group underwent triple vessel ligation (bilateral internal iliac and inferior mesenteric arteries) without any postoperative colonic ischaemia. In an additional study consisting of eight patients with vasculogenic impotence and/or hip claudication, the effectiveness of surgery was assessed by the increase in amplitude of the Doppler signals following reconstruction of the internal iliac artery. Following successful internal iliac reconstruction, an improvement in the amplitude of the waveform could be observed and followed postoperatively. In conclusion, the transanal Doppler probe can be used to follow the adequacy of the pelvic circulation allowing safer aorto-iliac and aorto-femoral surgery.

Aged↗

Gray scale sonographic anatomy of the pancreas.

With the development of gray scale, the appearance of pancreatic anatomy and its relationship to surrounding structures can be demonstrated more effectively. Gray scale has made it possible to identify such vessels as the portal vein, superior mesenteric vein, superior mesenteric artery, splenic vein, etc. This makes it possible to identify the pancreas more precisely. The normal pancreas appears to have a fairly specific echo pattern. The pancreas scanning techniques used in this study include the oblique, transverse, and longitudinal sections. Oblique views are especially useful.

Abdomen↗

Type II single umbilical artery (persistent vitelline artery) in an otherwise normal fetus.

A single umbilical artery resulting from absence of the umbilical arteries and persistence of the vitelline artery that arises directly from the abdominal aorta has been described only in malformed fetuses with sirenomelia or caudal regression. Such an aberrant artery was suggested to be the etiology of sirenomelia caused by a 'steal' mechanism of blood flow from the caudal end of the embryo. We present a case in which prenatal ultrasound showed a similar aberrant single artery arising from the abdominal aorta in an otherwise normal fetus with a normal course of pregnancy. This vessel, a continuation of the superior mesenteric artery (SMA), corresponds to a persistent vitelline artery assuming the function of the umbilical arteries. The etiology of such a finding and its possible consequences are discussed.

Adult↗

Postoperative adjuvant therapy for pancreatic cancer.

The majority of patients diagnosed with pancreatic cancer present at an advanced stage, and only a small percentage are considered technically resectable at diagnosis. The overall prognosis for the majority is dismal, with a median survival in untreated cases of only 24 weeks. Even in resected patients the overall 5-year survival rate is generally only 5% to 10%; however, some reports indicate higher 5-year survival rates in patients treated with surgery who are pathologically staged with no lymph node involvement. Even when macroscopically complete resection is achieved, local recurrence (LR) rates are unacceptably high (30% to 70%), which is usually attributed to the difficulty of obtaining microscopically free surgical margins. Microscopic clearance is difficult to achieve because these tumors frequently extend into the peripancreatic tissues (e.g., retropancreatic fat), abut or invade the adjacent large vessels (the portal vein and superior mesenteric artery), and have a propensity to invade the lymphovascular and perineural space. Other common sites of failure after attempted curative resection include metastasis to the liver and the peritoneal cavity. Patients who present with pancreatic cancer, and for whom curative surgery is deemed possible, are thus potential candidates for adjuvant therapy because of the high local failure rate following resection alone. The radiotherapy dose that can be achieved in the postoperative setting for pancreatic cancer is limited because of the proximity of critical structures (e.g., the kidney, liver, small intestines, stomach, and spinal cord). Newer techniques such as conformal radiotherapy and intensity-modulated radiotherapy have the advantage of being able (theoretically) to precisely localize the dose to the target volume while reducing the dose to critical structures. These techniques may potentially enable the tumorcidal dose to be increased; however, they are only now becoming widespread. Systemic radiation-sensitizing chemotherapy is also a promising approach to take advantage of additive or synergistic effects with radiation locally, and for the sterilization of systemic disease. This concept of concomitant chemotherapy with radiotherapy, or chemoradiotherapy, has proved effective in a number of sites, including the anal canal, rectum, lung, and pancreas. The recent trials reviewed here varied considerably in terms of the total dose and technique used, and the choice of radiation sensitizing treatment.

Chemotherapy, Adjuvant↗

Ionic dependence of electrical activity in small mesenteric arteries of guinea-pigs.

The regulation of blood vessel diameter is under the control of the autonomic nervous system (as well as hormones and metabolites), sympathetic nerve stimulation evoking depolarizing post-synaptic potentials. Excitatory junction potentials (EJPs) were recorded from vascular smooth muscle cells of guinea-pig small mesenteric arteries (pressurized) following nerve stimulation. Repetitive stimulation (greater than 5Hz) led to summation of EJPs, which evoked spikes and vasoconstriction. Replacing extracellular Na+ with choline (plus atropine) resulted in a decrease in EJP amplitude, but spike amplitude and maximum rate of rise (+Vmax) were unaffected. Decreasing the Ca2+ concentration produced decreases in EJP amplitude and spike +Vmax. Verapamil and bepridil, agents that depress Ca2+ influx in vascular and visceral smooth muscle, depolarized the membrane and depressed EJPs and spikes at higher concentrations (10(-5) M and 5 X 10(-6) M, respectively). The data indicate that EJPs are dependent on external Na+ and Ca2+ ions, and that spikes are dependent on Ca2+. Thus, neuromuscular transmission in this muscle is similar to that in non-vascular smooth muscles, such as intestinal muscles and vas deferens.

Animals↗

Chronic rejection of small bowel grafts: pediatric and adult study of risk factors and morphologic progression.

One hundred and seventy-two patients underwent small bowel transplantation at Children's Hospital of Pittsburgh and University of Pittsburgh Medical Center between May 1990 and August 2001. Thirty-four patients had complete or partial resection of their primary graft and in 15, histologic features of chronic rejection were present in the resected small bowel. This is a descriptive and correlative study of the demographic, perioperative, and histologic features associated with progression to intestinal graft failure. Variable features associated with an increased risk of chronic rejection included acute rejection within the 1st month, increased number and higher grade of acute rejection episodes, isolated small bowel grafts rather than small bowel-liver grafts, older recipient age, non-Caucasian race, and Caucasian to non-Caucasian transplant. The mucosal biopsies showed predictive changes many months before the grafts were excised. The mucosal biopsy diagnosis of chronic vascular rejection can be difficult because the affected vessels, the distal branches of the mesenteric arteries, and the larger arteries of the subserosa and submucosa are not routinely sampled. The possibility of underlying arteriopathy, however, can be inferred in some instances from the presence of secondary mucosal changes in the small bowel biopsies though the "early" changes lack specificity. It is the progression of biopsy findings over time that is predictive of outcome. It is important to recognize the persistence of "late" mucosal changes of chronic rejection so that patients are not subjected to increased immune suppression when it is unlikely to be of significant benefit.

Adolescent↗

Failure of duplex sonography to diagnose hepatic artery thrombosis in a high-risk group of pediatric liver transplant recipients.

Excellent correlation between angiographic findings and duplex sonography has been previously reported in the diagnosis of hepatic artery thrombosis (HAT), the most common technical complication of pediatric orthotopic liver transplantation (OLT). We now report a significant incidence of false-negative sonograms, ie, hepatic artery reported as patent but thrombosed on subsequent angiography. HAT was diagnosed in 10 of 57 pediatric OLT recipients evaluated prospectively by duplex sonography. In 5 patients HAT was diagnosed only by angiography even though arterial wave forms were observed on duplex sonography. Selective angiography demonstrated extensive collateral vessel formation arising from the superior mesenteric artery, the celiac axis, or both. The 5 patients shared very similar clinical courses marked by relapsing bacteremias with multiple enteric organisms, associated with focal infarctions of the liver. Four of the grafts had difficult arterial reconstructions and 3 of 5 had segmental bile duct dilation. We conclude that duplex sonography has proven to be a valuable screening tool in evaluating hepatic artery patency but must be correlated with angiography studies in a high-risk group of pediatric transplant patients characterized clinically by relapsing bacteremia and radiographically by false-negative duplex examinations.

Child↗

Bombesin-like immunoreactive material in the gut, and the effect of bombesin on the stomach circulatory system of an elasmobranch fish, Squalus acanthias.

The distribution, nature and amount of bombesin-like immunoreactivity (IR) in the gastrointestinal canal and its afferent vessels was investigated in the spiny dogfish (Squalus acanthias) together with the in vitro effect of synthetic bombesin on perfusion flow through the vascularly perfused dogfish stomach. Nerve fibres showing bombesin-like IR frequently occurred in the walls of the anterior mesenteric and coeliac arteries and the intrinsic vessels of the gut. Chromatographic studies revealed that multiple peaks of bombesin-like IR material were present in extracts of the spiny dogfish gastrointestinal vessels. Bombesin-like IR was also present in muscle and mucosal layers of the gut with higher levels in muscle compared with mucosa, and higher levels in the stomach than in the intestine and the rectum. Exogenous bombesin increased the flow through the vasculary perfused spiny dogfish stomach in a dose-dependent manner. Studies with tetrodotoxin and atropine showed that bombesin probably exerts its effect directly on the vascular musculature. It is concluded from this study that bombesin-like material is present in nerves innervating the gut circulatory system of the spiny dogfish. Bombesin may affect the blood-flow to the gastrointestinal canal, possibly via a direct effect on vascular smooth muscle.

Animals↗

Desmoid tumors: local control and patterns of relapse following radiation therapy.

Desmoid tumors are benign neoplasms, arising from musculoaponeurotic tissues, which tend to be locally infiltrative, resulting in a high rate of local recurrence following surgical resection. Nineteen patients with desmoid tumors underwent radiation therapy at the University of California, San Francisco, between 1970 and 1980. Fifteen patients were referred with local recurrence following one or more surgical resections. Three patients were referred for initial radiation therapy with unresectable tumors, and one patient received planned postoperative irradiation following subtotal tumor resection. At the time of treatment, 8 patients had nonresectable disease measuring greater than 10 cm. Five patients had residual tumor masses measuring 4 to 6 cm, and six had only microscopic disease following resection. The majority of patients were treated to a tumor dose of 50-55 Gy at 1.6 to 1.8 Gy per fraction. With a median follow-up of 8 years, 13 patients remained free of recurrent disease following radiation therapy. The 5 year relapse free survival was 72% with 10 patients continuing to be free of disease 5 to 11 years following therapy. Local control was not related to the amount of disease present at the time of treatment. Of the 6 patients who developed recurrent disease, only 1 patient had a true in-field recurrence. Four patients recurred at the margin of the radiation field 1 to 5 years following therapy. Of these four patients, 3 were successfully salvaged while 1 died as a result of tumor extension into a major vessel. One patient with an extensive mesenteric mass did not respond to therapy and died 1 month post irradiation. The patient with the in-field recurrence and 1 patient with a marginal recurrence were successfully treated with combination chemotherapy. Moderate dose radiation therapy to desmoid tumors can result in lasting local control when surgical resection is not possible. Post operative radiation can improve the rate of local control for patients with a high risk of recurrence. As desmoid tumors tend to be locally infiltrative, fields must be very generous to prevent marginal recurrence. Systemic chemotherapy offers an alternative to ablative surgery in the event of local failure following radiation therapy.

Adolescent↗