colorectal cancer is the third most common cancer ( ~1.2 million new cases are diagnosed each year ) , and the fourth cancer - associated cause of mortality in the world 's population ( 1 ) . approximately 20% of patients have at the time of presentation metastasized colorectal cancer , which is incurable in ~80% of cases ( 1 ) . although , during the last two decades , there has been an increase in the survival rate of end - stage patients of 814 months , and even 2 years or more in certain cases , predominantly due to novel chemotherapeutic agents , the quality of life may be severely affected ( 1 ) . international guidelines recommend that an incurable metastasized colorectal cancer should not be resected although , in practice , the therapeutic approach varies widely : two - thirds of cases are operated on in the united states whereas , in the netherlands , the majority of patients do not receive surgery ( 1 ) . considerable perioperative mortality and morbidity following incurable colorectal cancer resection should be weighed against a supposed longer survival rate ( 1 ) . an innovative approach to metastasized colorectal cancer , the tumor is completely devascularized by the ligature of all arteries and veins , and left in situ in the body . this provokes a generalized immune response to tumor antigens , and leads not only to the elimination of the devascularized tumor , but possibly also to the elimination of distant lesions without causing sepsis ( 2 ) . the czech surgeon , karel fortn , coincidentally discovered this technique when he operated a patient wounded by gunfire . besides the injury , the patient was also suffering from a metastasized inoperable stomach tumor . to prolong the life of the patient , the surgeon arrested all hemorrhage and performed a jejunal stomach bypass . due to its invasive nature , the tumor could not be completely resected , and was therefore left completely devascularized in the body . unexpectedly , the patient fully recovered in the following months , with no relapse of the cancer years later ( 2 ) . following this emergency operation , the surgeon realized that the remaining completely devascularized tumor apparently provoked an immune response against tumor cells . after this case , following the identical procedure , dr fortn operated several patients presenting predominantly colorectal cancer , though also patients with stomach and kidney cancer ( 35 ) . animal models and other studies elucidated the immunological working priniciple of this technique ( 2,6 ) . it has thus been demonstrated that total devascularization of the primary tumor , with the interruption of all blood vessels ( arteries and veins ) , promotes apoptosis of tumor cells , while circulating leukocytes are massively mobilized and accumulate at the periphery of the devascularized tumor under the influence of liberated stress - signaling factors , predominantly heat - shock proteins ( 6 ) . this allows phagocytosis of cellular debris to occur by antigen - presenting cells , and the normal processing of non - denatured tumor antigens for presentation to cytotoxic t - lymphocytes . finally , this leads to the specific activation of cytotoxic t - lymphocytes by all tumor - specific antigens and tumor - associated antigens through co - stimulation , also involving tumor - infiltrating lymphocytes and memory t - lymphocytes , which conjointly effect the elimination of lesions ( 2 ) . the method resembles other immune therapies , such as specific tumor antigen vaccines and tumor cell lysate - pulsed , dendritic cell - based cancer vaccines , with the main difference being that , for the atid technique , the specific activation of cytotoxic t - lymphocytes against all the potential tumor antigens proceeds entirely in vivo , with the involvement of all co - stimulating mediators of the immune system . in the present study , a case is described of a patient who presented with an invasive colorectal carcinoma , after having undergone atid with 14 years of clinical follow - up . a 48-year - old man with a history of rectal bleeding and increased frequency of loose stools for 6 months underwent colonoscopy in the polyclinic eleznin , olomouc czech republic , on january 25 , 2001 . a polyp ( measuring 35 cm ) located 17 cm from the anus was detected as the source of hemorrhage . five biopsies were taken , and directly fixated in 10% formalin and paraffin , whereafter slices of 34 m were stained with hematoxylin and eosin . ct scans with contrast per os and per rectum of the pelvis and rectum did not reveal any other suspect lesions or enlarged lymph nodes . due to the histological outcome , with no suspicion of malignant transformation due to its size , the polyp was resected in parts on february 7 , 2001 . histology of the whole polyp , performed as described above , revealed adenocarcinoma invading the muscularis propria , free of tumor cells at the cutting edges , staged as pt2 , nx , mx . follow - up with rectoscopies in march , june and september 2001 and biopsy of the scar from the previous tumor resection taken in march 2001 did not reveal any malignancy . in september 2001 , also , the level of carcinoembryonic antigen ( cea ) was revealed to be negative . all further examinations were negative up to january 14 , 2002 , at which time ultrasound of the abdomen revealed two suspect lesions in the right liver lobe . a colonoscopy also performed on january 14 , 2002 , a small polyp of 2 mm in diameter was resected near the distal part of the scar from the previous polypectomy performed in 2001 . further histological analysis revealed adenocarcinoma in situ originating from the cylindrical colon epithelium , although invasion was not detected . the patient was informed of the histological outcome and the suspect lesions in the liver , which urged the necessity to undergo further examinations to reveal the extent of the cancer . this was refused , and the patient sought directly the possibility of an atid intervention at the podripska hospital . in podripska hospital , ultrasound examination of the liver confirmed the presence of two suspect hypodense lesions in the right liver lobe measuring 14 mm ( 1.5 cc ) and 9 mm ( 0.5 cc ) in diameter . therefore , the decision was taken not to wait for ct scans of the rectum and abdomen , which at that time could not have been performed in the same hospital and would lead to a delay of several weeks , but to perform atid directly . the body weight and height of the patient were 72 kg and 175 cm , respectively ( body mass index : 23.5 ) . initial biochemical analyses revealed only a slight increase in the levels of non - conjugated and overall bilirubin . c - reactive protein ( crp ) , cea and cancer antigen 199 ( ca19 - 9 ) values were revealed to be within normal limits , or negative . furthermore , blood counts were within the normal range . on february 15 , 2002 , the patient underwent atid through a lower middle laparotomy . a tumor ( measuring 8 cm by 5 cm ; 220 cc ) the tumor , which had invaded perirectal fat tissue , the prostate , periosteum of the os sacrum and os coccygis , was first enucleated from the invaded tissues . liver metastases were not palpable . due to its invasive nature in surrounding tissues , without considering lesions in the liver , the tumor was determined to be at stage t4 , nx , mx . the mesorectum was subsequently released and ligated . then , the rectum and its lumen were closed by ligatures applied 1 cm proximally , and 3 cm distally , from the tumor . drains were placed inside the pelvis , and the laparotomy was closed according to the normal procedure with sutures : peritoneum and aponeurosis together with a continuous resorbable suture , subcutaneous tissue with single resorbable sutures , and skin with single non - resorbable sutures . antibiotic regimen was applied with amoxicillin 1,000 mg and clavulanic acid 200 mg every 8 h and gentamicin 240 mg every 24 h intravenously starting 30 min prior to operation during 7 days . hereafter amoxicillin 875 mg and clavulanic acid 125 mg per os twice daily was given 3 days . the first day after the intervention , the temperature of the patient rose to ~38c . due to discharges from the rectum 13 days following the operation , a rectoscopy was performed , and biopsy samples of possibly necrotic tissue were taken at a distance of 8 cm from the rectum . . increased postoperative levels of crp and the white blood count returned to within the normal range in 2 months . regular check - ups were not performed due to the patient 's non - compliance . eleven years later , as determined on may 23 , 2013 , subsequent ct scans did not reveal any malignancy , and all tumor and inflammation markers were within the normal range . in august 2016 the presented case of an invasive colorectal tumor reveals the clinical safety of atid , and also indicates both the immunizing and the curative potential of this method . total devascularization of the tumor mass ( ~220 cc ) was well tolerated by the patient , without any serious side - effects and resulted in a curative outcome , with a symptom - free survival rate exceeding 14 years . furthermore , following the operation , the patient reported only mild pain , comparable with that of a standard laparotomy . this case of colorectal adenocarcinoma could not be resolved by conventional oncological surgery , and corresponded with stage iv in view of its invasiveness and size alone . model calculations in order to predict the possibility of the elimination of metastases , and thus the curative effect of atid , were performed retrospectively ( table i ) ( 2 ) . in february 2001 , histological examinations of a resected polyp revealed adenocarcinoma . on the ground of the presumption that the tumor was not completely resected , and therefore could grow back to the same volume it occupied at the time of the operation from only a micrometastase , a retrospective calculation was performed . the retrospective calculation was based on the estimated volume of the primary tumor ( 220 cc ) and of two presumed metastases ( 1.5 and 0.5 cc ) when atid was performed a year later . assuming that the primary tumor , with a hypothetical doubling time of ~14 days , developed over a period of 1 year ( corresponding to an aggressive tumor ) , calculations revealed that the tumor ( 220 cc ) would have originated from an undetectable locus or micrometastase of only 5.410 cc , i.e. ~5,400 tumor cells . even in assuming the presence of a tumor that was much more aggressive , with a doubling time of only ~10 days , model calculations indicated possible elimination of the presumed metastases within ~60 days ( table i ) ( 2 ) . therefore , assuming a doubling time of 7 days , according to the calculations larger metastases would regrow ( table i ) . the rate of immunolysis of the tumor should be higher compared with the tumor growth rate . in the early development of a tumor , the growth rate may be much higher in comparison with the later stages , when the tumor is larger and detectable ( 7 ) . this explains why choi et al ( 8) were able to identify high variability in the tumor - volume doubling times ( from 0.057.1 years ) . thus , the more aggressive the tumor , the greater the percentage of the total tumor mass that should be devascularized . for the purpose of clinical orientation , the amount of tumor mass devascularization is expressed as the ratio of devascularization ( rd ) : ( volume of devascularized tumor)/(total volume of remaining metastases ) . calculating the rd provides the clinician with an indication as to whether atid could be curative . besides rd , the tumor volume - doubling time and the volume of the largest metastase are important factors in the calculation . in more common cases with slowly growing tumors , such as in the case of colorectal cancer , rd values of the results of comparative simulations of immunolysis , calculated with various tumor - doubling times , the volume of the devascularized primary tumor and volumes of metastases , are shown in table i. unfortunately , due to the non - compliance of the patient to undergo regular check - ups , the regression of metastases was not monitored . however , on ct scans 1 year following atid , no hypodense lesions were observed . in future studies , the immunolysis of metastases should therefore be monitored with short intervals to allow further development of the atid calculation model . to calculate the possible curative effect of atid , magnetic resonance imaging scans and positron emission tomography scans , which are even more precise , are necessary for the estimation of tumor - volume doubling times ( 2 ) . the curative outcome in the application of atid , and absence of undesirable side - effects described in the present case study fully reflect the results obtained in numerous animal model experiments and clinical studies involving the devascularization of tissues and organs . when performing atid , it is very important to ensure perfect total devascularization . double ligatures have to be tight and performed exclusively with non - resorbable stitching material . in anatomically indicated situations , in order to prevent collateral blood supply by microvessels along the periphery of the tumor , it is necessary to apply tight mattress stitches to isolate the tumor completely for optimal immunolysis . this is to ensure the longest possible duration of a high systemic concentration of activated cytotoxic t - lymphocytes ( see the cl values , i.e. the percentage of the maximum systemic concentration of cytotoxic lymphocytes following the time of complete immunolysis or beginning of regrowth , in table i ) . on the macroscopic level , the devascularized tissue first increases in size ; subsequently , shrinking occurs , and the devascularized tissue is eventually replaced by fibrous tissue ( 4 ) . on the microscopic level , during the first 2 days the numbers of infiltrating mono- and polynuclear lymphocytes are observed to increase ( 3 ) . over the course of the next 8 weeks , cells of the devascularized tissue are replaced by fibrinous connective tissue , and the concentration of leukocytes decreases ( 3 ) . the lack of any serious side - effects is predominantly explained by the circumstance that the discharge into the system of any liberated inflammatory components due to atid can only proceed very slowly by diffusion . the absence of serious side - effects may also be explained by the high concentration of immune cells accumulating at the periphery of the devascularized tissue ( 3,6 ) . the strategy of leaving completely ligated tissue or devascularized tissue in the human or animal body is not entirely novel . former studies , discussed in this chapter have revealed that various organs with complete devascularization involving the artery and vein blood supply can be left in the body without serious side - effects . examples taken from animal studies include transplantation of the hypophysis following total resection in the rectus muscle , bone marrow of the tibia and cortex cerebri in dogs ( n=23 ) , thereby prolonging life compared with resection alone ( 9 ) , the ligation of intestines up to 180 cm in length in pigs ( n=47 ) ( 3,10 ) without any side - effects , even following injection of pathogenic bacteria into the stomachs of pigs ( n=23 ) ( 11 ) , and the ligation of parathyroid glandules in dogs ( n=14 ) ( 12 ) , the spleen in rats ( n=35 ) ( 13 ) and a guinea - pig ( n=1 ) ( 14 ) , kidneys in pigs ( n=21 ) and rats ( n=60 ) ( 4 ) , testes in dogs ( n=3 ) ( 15 ) and cocks ( n=4 ) ( 16 ) , and ovaries in dogs ( n=6 ) ( 17 ) . following devascularization of the colon , no migration of bacteria through the ischemic wall similarly in humans , the devascularization of organs has been performed without serious side - effects . in the case of hyperthyroid patients ( n=225 ) , the surgeon charles h. mayo , for the purpose of safety and simplicity of the operation , advocated arterial and venous thyroidal vessel ligation while leaving the devascularized part of the thyroid gland in situ ( 19 ) . other examples are provided by the devascularization of half the thyroid gland followed by transplantation in the abdomen ( n=4 ) ( 20 ) , preference of renal artery and vein ligation ( n=1 ) over nephrectomy ( 21 ) , devascularization with rubber bands of hyperplastic gastric polyps ( n=72 ) ( 22 ) , and in utero percutaneous umbilical cord ligation in complicated monochorionic multiple gestations ( n=11 ) ( 23 ) . animal studies have been performed where tumors have been completely devascularized without any serious side - effects . examples of primary tumor devascularization are the lewis lung carcinoma cell line being implanted into the hind - limbs of mice with 4 to 5-fold reduced lung metastases ( 24 ) , the murine osteosarcoma cell line pos-1 being implanted into the thighs of mice ( n=15 ) with a marked reduction in lung metastases ( 25 ) , and a temporary clamping of the tumor in the murine ca nt tumor model in mice , where progressively decreased tumor cell survival is observed following increasing periods of vascular occlusion ( 26 ) . notably , experiments with inoculated flexnor - jobling carcinoma , the cracker sarcoma 39 and the walker tumor in the legs of rats revealed that complete regression without recurrence was obtained after 79 h of temporary ligation with rubber bands ( 27 ) . in addition , temporary ligation with rubber bands in dogs revealed total necrosis in 29 out of 41 benign tumors , including lipomas , angiomas , adenomas and mixed mammary tumors , and all eight malignant tumors , including mammary and perianal adenocarcinoma , fibrosarcoma , squamous cell carcinoma and melanoma ( 28 ) . the effect of atid on distant metastases has been investigated in miniature pigs ( n=40 ) with hereditary melanoblastoma ( 6 ) . the reduction in the number of metastases was observed 2 weeks following atid , with complete elimination of all non - treated metastases over the course of 46 months ( 6 ) . in humans , the curative effects of atid atid was performed on a 63-year - old female with a carcinoma ( 1512 cm , ~450 cc ) in the left colon invading into the spleen , pancreas , mesocolon transversum , and left kidney ( 3 ) . six months later , a control laparotomy did not reveal the presence of any metastases , but only a small amount of fibrotic tissue of the devascularized part . a 57-year - old male , with a colon carcinoma ( size of a double fist , ~500 cc ) with infiltration of the abdominal wall and a few liver metastases , underwent atid ( 3 ) . the two patients were living in good health at the time of the publication of the studies , 7 years following atid . atid was performed on a 66-year - old patient , who had a carcinoma ( size of a fist , ~250 cc ) in the colon sigmoideum with invasion into the small intestines , a few liver metastases and a metastase in the small intestine ( 3 ) . following 5 years of living in good health , a 41-year - old man with a colorectal carcinoma ( ~300 cc ) and liver metastases , who stopped chemotherapy following the first dosage due to severe side - effects , underwent atid ( 2 ) . nearly 3 years after the atid intervention , the patient succumbed suddenly to myocardial infarction . two patients , who were 79 and 82-year - old men with colorectal cancers [ 43 cm ( ~40 cc ) and walnut - sized ( ~30 cc ) , respectively ] without detectable metastases ( 3 ) , died 4 and 5 years following atid , respectively . obduction revealed no metastases , and , in both cases , icterus ( jaundice ) was the cause of death . in a 65-year - old man who had a kidney adenocarcinoma with infiltration of the peritoneum , atid was successfully performed , and the patient enjoyed 3 years of good health ( 4 ) . additionally , a large ileal lipoma ( n=1 ) was successfully devascularized ( 29 ) . all these results clearly demonstrate that devascularization of tissue and tumors is well tolerated in a wide variety of situations in both animal model and clinical studies . it is now possible to explain the therapeutic effects , and even to predict curative outcomes , on the basis of atid theory ( 2 ) . in conclusion , the present case study has clearly indicated the critical clinical conditions for atid that should be respected if the intention is a curative outcome . concerning clinical safety , this case is comparable with that of standard laparotomy . furthermore , the safety of leaving a large mass of completely devascularized tissue and/or tumor in the body has been verified in animal models and clinical studies . the therapeutic potential of atid should be investigated in clinical studies under optimal , well - defined conditions , ensuring maximum therapeutic benefits to patient volunteers . these studies could also provide the clinical basis for an investigation of the potentiating mechanisms in the activation of the cellular immune system against all tumor antigens . the maximal activities of the specific cytokines and immune cell growth factors should be established in association with the phases of immunolysis . with the application of suitable potentiating agents at their optimal concentrations , and at the most clinically beneficial time , the presence of high systemic levels of activated cytotoxic t - lymphocytes could be sustained for longer periods . this may consequently increase the chances of a curative outcome , particularly in cases of very aggressive cancers . model calculations in order to predict the possibility of the elimination of metastases , and thus the curative effect of atid , were performed retrospectively ( table i ) ( 2 ) . in february 2001 , histological examinations of a resected polyp revealed adenocarcinoma . on the ground of the presumption that the tumor was not completely resected , and therefore could grow back to the same volume it occupied at the time of the operation from only a micrometastase , a retrospective calculation was performed . the retrospective calculation was based on the estimated volume of the primary tumor ( 220 cc ) and of two presumed metastases ( 1.5 and 0.5 cc ) when atid was performed a year later . assuming that the primary tumor , with a hypothetical doubling time of ~14 days , developed over a period of 1 year ( corresponding to an aggressive tumor ) , calculations revealed that the tumor ( 220 cc ) would have originated from an undetectable locus or micrometastase of only 5.410 cc , i.e. ~5,400 tumor cells . even in assuming the presence of a tumor that was much more aggressive , with a doubling time of only ~10 days , model calculations indicated possible elimination of the presumed metastases within ~60 days ( table i ) ( 2 ) . therefore , assuming a doubling time of 7 days , according to the calculations larger metastases would regrow ( table i ) . the rate of immunolysis of the tumor should be higher compared with the tumor growth rate . in the early development of a tumor , the growth rate may be much higher in comparison with the later stages , when the tumor is larger and detectable ( 7 ) . this explains why choi et al ( 8) were able to identify high variability in the tumor - volume doubling times ( from 0.057.1 years ) . thus , the more aggressive the tumor , the greater the percentage of the total tumor mass that should be devascularized . for the purpose of clinical orientation , the amount of tumor mass devascularization is expressed as the ratio of devascularization ( rd ) : ( volume of devascularized tumor)/(total volume of remaining metastases ) . calculating the rd provides the clinician with an indication as to whether atid could be curative . besides rd , the tumor volume - doubling time and the volume of the largest metastase are important factors in the calculation . in more common cases with slowly growing tumors , such as in the case of colorectal cancer , rd values of the results of comparative simulations of immunolysis , calculated with various tumor - doubling times , the volume of the devascularized primary tumor and volumes of metastases , are shown in table i. unfortunately , due to the non - compliance of the patient to undergo regular check - ups , the regression of metastases was not monitored . however , on ct scans 1 year following atid , no hypodense lesions were observed . in future studies , the immunolysis of metastases should therefore be monitored with short intervals to allow further development of the atid calculation model . to calculate the possible curative effect of atid , magnetic resonance imaging scans and positron emission tomography scans , which are even more precise , are necessary for the estimation of tumor - volume doubling times ( 2 ) . the curative outcome in the application of atid , and absence of undesirable side - effects described in the present case study fully reflect the results obtained in numerous animal model experiments and clinical studies involving the devascularization of tissues and organs . when performing atid , it is very important to ensure perfect total devascularization . double ligatures have to be tight and performed exclusively with non - resorbable stitching material . in anatomically indicated situations , in order to prevent collateral blood supply by microvessels along the periphery of the tumor , it is necessary to apply tight mattress stitches to isolate the tumor completely for optimal immunolysis . this is to ensure the longest possible duration of a high systemic concentration of activated cytotoxic t - lymphocytes ( see the cl values , i.e. the percentage of the maximum systemic concentration of cytotoxic lymphocytes following the time of complete immunolysis or beginning of regrowth , in table i ) . on the macroscopic level , the devascularized tissue first increases in size ; subsequently , shrinking occurs , and the devascularized tissue is eventually replaced by fibrous tissue ( 4 ) . on the microscopic level , during the first 2 days the numbers of infiltrating mono- and polynuclear lymphocytes over the course of the next 8 weeks , cells of the devascularized tissue are replaced by fibrinous connective tissue , and the concentration of leukocytes decreases ( 3 ) . the lack of any serious side - effects is predominantly explained by the circumstance that the discharge into the system of any liberated inflammatory components due to atid can only proceed very slowly by diffusion . the absence of serious side - effects may also be explained by the high concentration of immune cells accumulating at the periphery of the devascularized tissue ( 3,6 ) . the strategy of leaving completely ligated tissue or devascularized tissue in the human or animal body is not entirely novel . former studies , discussed in this chapter have revealed that various organs with complete devascularization involving the artery and vein blood supply can be left in the body without serious side - effects . furthermore , replacement with fibrous tissue has been observed . examples taken from animal studies include transplantation of the hypophysis following total resection in the rectus muscle , bone marrow of the tibia and cortex cerebri in dogs ( n=23 ) , thereby prolonging life compared with resection alone ( 9 ) , the ligation of intestines up to 180 cm in length in pigs ( n=47 ) ( 3,10 ) without any side - effects , even following injection of pathogenic bacteria into the stomachs of pigs ( n=23 ) ( 11 ) , and the ligation of parathyroid glandules in dogs ( n=14 ) ( 12 ) , the spleen in rats ( n=35 ) ( 13 ) and a guinea - pig ( n=1 ) ( 14 ) , kidneys in pigs ( n=21 ) and rats ( n=60 ) ( 4 ) , testes in dogs ( n=3 ) ( 15 ) and cocks ( n=4 ) ( 16 ) , and ovaries in dogs ( n=6 ) ( 17 ) . following devascularization of the colon , no migration of bacteria through the ischemic wall was observed for up to 6 h ( 18 ) . similarly in humans , the devascularization of organs has been performed without serious side - effects . in the case of hyperthyroid patients ( n=225 ) , the surgeon charles h. mayo , for the purpose of safety and simplicity of the operation , advocated arterial and venous thyroidal vessel ligation while leaving the devascularized part of the thyroid gland in situ ( 19 ) . other examples are provided by the devascularization of half the thyroid gland followed by transplantation in the abdomen ( n=4 ) ( 20 ) , preference of renal artery and vein ligation ( n=1 ) over nephrectomy ( 21 ) , devascularization with rubber bands of hyperplastic gastric polyps ( n=72 ) ( 22 ) , and in utero percutaneous umbilical cord ligation in complicated monochorionic multiple gestations ( n=11 ) ( 23 ) . animal studies have been performed where tumors have been completely devascularized without any serious side - effects . examples of primary tumor devascularization are the lewis lung carcinoma cell line being implanted into the hind - limbs of mice with 4 to 5-fold reduced lung metastases ( 24 ) , the murine osteosarcoma cell line pos-1 being implanted into the thighs of mice ( n=15 ) with a marked reduction in lung metastases ( 25 ) , and a temporary clamping of the tumor in the murine ca nt tumor model in mice , where progressively decreased tumor cell survival is observed following increasing periods of vascular occlusion ( 26 ) . notably , experiments with inoculated flexnor - jobling carcinoma , the cracker sarcoma 39 and the walker tumor in the legs of rats revealed that complete regression without recurrence was obtained after 79 h of temporary ligation with rubber bands ( 27 ) . in addition , temporary ligation with rubber bands in dogs revealed total necrosis in 29 out of 41 benign tumors , including lipomas , angiomas , adenomas and mixed mammary tumors , and all eight malignant tumors , including mammary and perianal adenocarcinoma , fibrosarcoma , squamous cell carcinoma and melanoma ( 28 ) . the effect of atid on distant metastases has been investigated in miniature pigs ( n=40 ) with hereditary melanoblastoma ( 6 ) . the reduction in the number of metastases was observed 2 weeks following atid , with complete elimination of all non - treated metastases over the course of 46 months ( 6 ) . in humans , atid was performed on a 63-year - old female with a carcinoma ( 1512 cm , ~450 cc ) in the left colon invading into the spleen , pancreas , mesocolon transversum , and left kidney ( 3 ) . six months later , a control laparotomy did not reveal the presence of any metastases , but only a small amount of fibrotic tissue of the devascularized part . a 57-year - old male , with a colon carcinoma ( size of a double fist , ~500 cc ) with infiltration of the abdominal wall and a few liver metastases , underwent atid ( 3 ) . the two patients were living in good health at the time of the publication of the studies , 7 years following atid . atid was performed on a 66-year - old patient , who had a carcinoma ( size of a fist , ~250 cc ) in the colon sigmoideum with invasion into the small intestines , a few liver metastases and a metastase in the small intestine ( 3 ) . following 5 years of living in good health , a 41-year - old man with a colorectal carcinoma ( ~300 cc ) and liver metastases , who stopped chemotherapy following the first dosage due to severe side - effects , underwent atid ( 2 ) . nearly 3 years after the atid intervention , the patient succumbed suddenly to myocardial infarction . two patients , who were 79 and 82-year - old men with colorectal cancers [ 43 cm ( ~40 cc ) and walnut - sized ( ~30 cc ) , respectively ] without detectable metastases ( 3 ) , died 4 and 5 years following atid , respectively . obduction revealed no metastases , and , in both cases , icterus ( jaundice ) was the cause of death . in a 65-year - old man who had a kidney adenocarcinoma with infiltration of the peritoneum , atid was successfully performed , and the patient enjoyed 3 years of good health ( 4 ) . additionally , a large ileal lipoma ( n=1 ) was successfully devascularized ( 29 ) . all these results clearly demonstrate that devascularization of tissue and tumors is well tolerated in a wide variety of situations in both animal model and clinical studies . it is now possible to explain the therapeutic effects , and even to predict curative outcomes , on the basis of atid theory ( 2 ) . in conclusion , the present case study has clearly indicated the critical clinical conditions for atid that should be respected if the intention is a curative outcome . concerning clinical safety , this case is comparable with that of standard laparotomy . furthermore , the safety of leaving a large mass of completely devascularized tissue and/or tumor in the body has been verified in animal models and clinical studies . the therapeutic potential of atid should be investigated in clinical studies under optimal , well - defined conditions , ensuring maximum therapeutic benefits to patient volunteers . these studies could also provide the clinical basis for an investigation of the potentiating mechanisms in the activation of the cellular immune system against all tumor antigens . the maximal activities of the specific cytokines and immune cell growth factors should be established in association with the phases of immunolysis . with the application of suitable potentiating agents at their optimal concentrations , and at the most clinically beneficial time , the presence of high systemic levels of activated cytotoxic t - lymphocytes could be sustained for longer periods . this may consequently increase the chances of a curative outcome , particularly in cases of very aggressive cancers . model calculations in order to predict the possibility of the elimination of metastases , and thus the curative effect of atid , were performed retrospectively ( table i ) ( 2 ) . in february 2001 , histological examinations of a resected polyp revealed adenocarcinoma . on the ground of the presumption that the tumor was not completely resected , and therefore could grow back to the same volume it occupied at the time of the operation from only a micrometastase , a retrospective calculation was performed . the retrospective calculation was based on the estimated volume of the primary tumor ( 220 cc ) and of two presumed metastases ( 1.5 and 0.5 cc ) when atid was performed a year later . assuming that the primary tumor , with a hypothetical doubling time of ~14 days , developed over a period of 1 year ( corresponding to an aggressive tumor ) , calculations revealed that the tumor ( 220 cc ) would have originated from an undetectable locus or micrometastase of only 5.410 cc , i.e. ~5,400 tumor cells . even in assuming the presence of a tumor that was much more aggressive , with a doubling time of only ~10 days , model calculations indicated possible elimination of the presumed metastases within ~60 days ( table i ) ( 2 ) . therefore , assuming a doubling time of 7 days , according to the calculations larger metastases would regrow ( table i ) . the rate of immunolysis of the tumor should be higher compared with the tumor growth rate . in the early development of a tumor , the growth rate may be much higher in comparison with the later stages , when the tumor is larger and detectable ( 7 ) . this explains why choi et al ( 8) were able to identify high variability in the tumor - volume doubling times ( from 0.057.1 years ) . thus , the more aggressive the tumor , the greater the percentage of the total tumor mass that should be devascularized . for the purpose of clinical orientation , the amount of tumor mass devascularization is expressed as the ratio of devascularization ( rd ) : ( volume of devascularized tumor)/(total volume of remaining metastases ) . calculating the rd provides the clinician with an indication as to whether atid could be curative . besides rd , the tumor volume - doubling time and the volume of the largest metastase are important factors in the calculation . in more common cases with slowly growing tumors , such as in the case of colorectal cancer , rd values of the results of comparative simulations of immunolysis , calculated with various tumor - doubling times , the volume of the devascularized primary tumor and volumes of metastases , are shown in table i. unfortunately , due to the non - compliance of the patient to undergo regular check - ups , the regression of metastases was not monitored . however , on ct scans 1 year following atid , no hypodense lesions were observed . in future studies , the immunolysis of metastases should therefore be monitored with short intervals to allow further development of the atid calculation model . to calculate the possible curative effect of atid , magnetic resonance imaging scans and positron emission tomography scans , which are even more precise , are necessary for the estimation of tumor - volume doubling times ( 2 ) . the curative outcome in the application of atid , and absence of undesirable side - effects described in the present case study fully reflect the results obtained in numerous animal model experiments and clinical studies involving the devascularization of tissues and organs . when performing atid , it is very important to ensure perfect total devascularization . double ligatures have to be tight and performed exclusively with non - resorbable stitching material . in anatomically indicated situations , in order to prevent collateral blood supply by microvessels along the periphery of the tumor , it is necessary to apply tight mattress stitches to isolate the tumor completely for optimal immunolysis . this is to ensure the longest possible duration of a high systemic concentration of activated cytotoxic t - lymphocytes ( see the cl values , i.e. the percentage of the maximum systemic concentration of cytotoxic lymphocytes following the time of complete immunolysis or beginning of regrowth , in table i ) . on the macroscopic level , the devascularized tissue first increases in size ; subsequently , shrinking occurs , and the devascularized tissue is eventually replaced by fibrous tissue ( 4 ) . on the microscopic level , during the first 2 days the numbers of infiltrating mono- and polynuclear lymphocytes are observed to increase ( 3 ) . over the course of the next 8 weeks , cells of the devascularized tissue are replaced by fibrinous connective tissue , and the concentration of leukocytes decreases ( 3 ) . the lack of any serious side - effects is predominantly explained by the circumstance that the discharge into the system of any liberated inflammatory components due to atid can only proceed very slowly by diffusion . the absence of serious side - effects may also be explained by the high concentration of immune cells accumulating at the periphery of the devascularized tissue ( 3,6 ) . the strategy of leaving completely ligated tissue or devascularized tissue in the human or animal body is not entirely novel . former studies , discussed in this chapter have revealed that various organs with complete devascularization involving the artery and vein blood supply can be left in the body without serious side - effects . furthermore , replacement with fibrous tissue has been observed . examples taken from animal studies include transplantation of the hypophysis following total resection in the rectus muscle , bone marrow of the tibia and cortex cerebri in dogs ( n=23 ) , thereby prolonging life compared with resection alone ( 9 ) , the ligation of intestines up to 180 cm in length in pigs ( n=47 ) ( 3,10 ) without any side - effects , even following injection of pathogenic bacteria into the stomachs of pigs ( n=23 ) ( 11 ) , and the ligation of parathyroid glandules in dogs ( n=14 ) ( 12 ) , the spleen in rats ( n=35 ) ( 13 ) and a guinea - pig ( n=1 ) ( 14 ) , kidneys in pigs ( n=21 ) and rats ( n=60 ) ( 4 ) , testes in dogs ( n=3 ) ( 15 ) and cocks ( n=4 ) ( 16 ) , and ovaries in dogs ( n=6 ) ( 17 ) . following devascularization of the colon , no migration of bacteria through the ischemic wall was observed for up to 6 h ( 18 ) . similarly in humans , the devascularization of organs has been performed without serious side - effects . in the case of hyperthyroid patients ( n=225 ) , the surgeon charles h. mayo , for the purpose of safety and simplicity of the operation , advocated arterial and venous thyroidal vessel ligation while leaving the devascularized part of the thyroid gland in situ ( 19 ) . other examples are provided by the devascularization of half the thyroid gland followed by transplantation in the abdomen ( n=4 ) ( 20 ) , preference of renal artery and vein ligation ( n=1 ) over nephrectomy ( 21 ) , devascularization with rubber bands of hyperplastic gastric polyps ( n=72 ) ( 22 ) , and in utero percutaneous umbilical cord ligation in complicated monochorionic multiple gestations ( n=11 ) ( 23 ) . animal studies have been performed where tumors have been completely devascularized without any serious side - effects . examples of primary tumor devascularization are the lewis lung carcinoma cell line being implanted into the hind - limbs of mice with 4 to 5-fold reduced lung metastases ( 24 ) , the murine osteosarcoma cell line pos-1 being implanted into the thighs of mice ( n=15 ) with a marked reduction in lung metastases ( 25 ) , and a temporary clamping of the tumor in the murine ca nt tumor model in mice , where progressively decreased tumor cell survival is observed following increasing periods of vascular occlusion ( 26 ) . notably , experiments with inoculated flexnor - jobling carcinoma , the cracker sarcoma 39 and the walker tumor in the legs of rats revealed that complete regression without recurrence was obtained after 79 h of temporary ligation with rubber bands ( 27 ) . in addition , temporary ligation with rubber bands in dogs revealed total necrosis in 29 out of 41 benign tumors , including lipomas , angiomas , adenomas and mixed mammary tumors , and all eight malignant tumors , including mammary and perianal adenocarcinoma , fibrosarcoma , squamous cell carcinoma and melanoma ( 28 ) . the effect of atid on distant metastases has been investigated in miniature pigs ( n=40 ) with hereditary melanoblastoma ( 6 ) . the reduction in the number of metastases was observed 2 weeks following atid , with complete elimination of all non - treated metastases over the course of 46 months ( 6 ) . in humans , the curative effects of atid atid was performed on a 63-year - old female with a carcinoma ( 1512 cm , ~450 cc ) in the left colon invading into the spleen , pancreas , mesocolon transversum , and left kidney ( 3 ) . six months later , a control laparotomy did not reveal the presence of any metastases , but only a small amount of fibrotic tissue of the devascularized part . a 57-year - old male , with a colon carcinoma ( size of a double fist , ~500 cc ) with infiltration of the abdominal wall and a few liver metastases , underwent atid ( 3 ) . the two patients were living in good health at the time of the publication of the studies , 7 years following atid . atid was performed on a 66-year - old patient , who had a carcinoma ( size of a fist , ~250 cc ) in the colon sigmoideum with invasion into the small intestines , a few liver metastases and a metastase in the small intestine ( 3 ) . following 5 years of living in good health , the patient died of a heart attack . a 41-year - old man with a colorectal carcinoma ( ~300 cc ) and liver metastases , who stopped chemotherapy following the first dosage due to severe side - effects , underwent atid ( 2 ) . nearly 3 years after the atid intervention , the patient succumbed suddenly to myocardial infarction . two patients , who were 79 and 82-year - old men with colorectal cancers [ 43 cm ( ~40 cc ) and walnut - sized ( ~30 cc ) , respectively ] without detectable metastases ( 3 ) , died 4 and 5 years following atid , respectively . obduction revealed no metastases , and , in both cases , icterus ( jaundice ) was the cause of death . in a 65-year - old man who had a kidney adenocarcinoma with infiltration of the peritoneum , atid was successfully performed , and the patient enjoyed 3 years of good health ( 4 ) . additionally , a large ileal lipoma ( n=1 ) was successfully devascularized ( 29 ) . all these results clearly demonstrate that devascularization of tissue and tumors is well tolerated in a wide variety of situations in both animal model and clinical studies . it is now possible to explain the therapeutic effects , and even to predict curative outcomes , on the basis of atid theory ( 2 ) . in conclusion , the present case study has clearly indicated the critical clinical conditions for atid that should be respected if the intention is a curative outcome . concerning clinical safety , furthermore , the safety of leaving a large mass of completely devascularized tissue and/or tumor in the body has been verified in animal models and clinical studies . the therapeutic potential of atid should be investigated in clinical studies under optimal , well - defined conditions , ensuring maximum therapeutic benefits to patient volunteers . these studies could also provide the clinical basis for an investigation of the potentiating mechanisms in the activation of the cellular immune system against all tumor antigens . such mechanisms may involve the application of specific cytokines and immune cell growth factors . this would require their peak concentrations to be determined . the maximal activities of the specific cytokines and immune cell growth factors should be established in association with the phases of immunolysis . with the application of suitable potentiating agents at their optimal concentrations , and at the most clinically beneficial time , the presence of high systemic levels of activated cytotoxic t - lymphocytes could be sustained for longer periods . this may consequently increase the chances of a curative outcome , particularly in cases of very aggressive cancers .
colorectal cancer is the third most common cancer . 
 approximately 20% of patients have at the time of presentation metastasized colorectal cancer , which is incurable in ~80% of cases . 
 the present case report describes a typical case diagnosed with an advanced invasive colorectal adenocarcinoma , with two suspect hypodense lesions in the liver , as revealed by sonography . 
 judged inoperable for a curative outcome by radical resection , the patient was treated with a novel surgical technique based on stimulating the immune system , termed  autologous tumor immunizing devascularization ( atid ) . 
 the tumor was isolated from its surroundings by ligature of arteries and veins , and subsequently the completely devascularized tumor was left in situ . 
 the distal part of the rectum was closed , and a stoma was made from the proximal part of the colon . 
 following atid , the stressing pathophysiological condition of the completely isolated tumor provoked a generalized cellular immune response , which led to the elimination of the devascularized tumor and distant lesions without causing sepsis . 
 the patient did not experience any serious side - effects following the operation , and refused any adjuvant chemo- and/or radiotherapy . to date 
 , the patient has no complaints and remains in good health after the atid intervention , already more than 14 years . 
 the present case study provides a typical demonstration of the clinical safety of atid , and also indicates both the immunizing and the curative potential of the method .