situs inversus is a congenital condition with an incidence ranging between 1:1000 and 1:10 000 characterized by left - to - right transposition of one or more normally asymmetrical organs of the body . situs inversus totalis ( sit ) consists of a mirror - image transposition of the abdominal and thoracic viscera , which occurs in about 1:5000 to 1:10 000 adults . patients affected by sit are usually completely asymptomatic , but they have more commonly major defects which can shorten their lifespan . to our knowledge , few cases of open liver resections for hepatocellular carcinoma in japanese patients with sit have been published . in addition , laparoscopic liver resections ( llrs ) in these patients have not been published by western authors . we herein present the case of a patient with a single colorectal liver metastasis with sit providing the readers with useful information to approach this condition . a 60-year - old male with known sit , operated in another hospital on july 2014 for sigmoid adenocarcinoma ( pt3n2 ) was referred to our center for a single metachronous liver metastasis ( 30  24 mm ) in segment 7 ( fig . the patient was placed in a right lateral position of 60 ; due to the previous midline incision , we chose an open laparoscopic access with the hasson trocar on the pararectal line . we used three 12 mm - subcostal trocars and two accessory 5 mm trocars , in the midline on the previous laparotomy and 5 cm laterally ( fig . a 7 s sub - segmentectomy was performed with harmonic scalpel , bipolar forceps and clips . the liver was attached at the diaphragm without the interposition of any ligament but directly to muscle . position of the patient on the operating table and position of the trocars . as usual , we performed an intraoperative ultrasonography with the mode of scanning was switched from normal to reverse modality ; so , it was possible to have on the screen the usual appearance of the intrahepatic anatomy despite of the present specular anatomy . we performed an intermittent ( 15 min with 5 min of release ) pringle maneuver for a total of 36 min . the patient had the first bowel movement on postoperative day 1 and he was started on oral feeding . no peri - operative complications occurred and he was discharged home 5 days after surgery . the specimen sent to pathology measured 7  3  5 cm with 0.9 cm clear resection margin . at 3-month follow - up , the patient was doing well and no complications have been observed . the patient was placed in a right lateral position of 60 ; due to the previous midline incision , we chose an open laparoscopic access with the hasson trocar on the pararectal line . we used three 12 mm - subcostal trocars and two accessory 5 mm trocars , in the midline on the previous laparotomy and 5 cm laterally ( fig . a 7 s sub - segmentectomy was performed with harmonic scalpel , bipolar forceps and clips . the liver was attached at the diaphragm without the interposition of any ligament but directly to muscle . position of the patient on the operating table and position of the trocars . as usual , we performed an intraoperative ultrasonography with the mode of scanning was switched from normal to reverse modality ; so , it was possible to have on the screen the usual appearance of the intrahepatic anatomy despite of the present specular anatomy . we performed an intermittent ( 15 min with 5 min of release ) pringle maneuver for a total of 36 min . the patient had the first bowel movement on postoperative day 1 and he was started on oral feeding . no peri - operative complications occurred and he was discharged home 5 days after surgery . the specimen sent to pathology measured 7  3  5 cm with 0.9 cm clear resection margin . at 3-month follow - up , the patient was doing well and no complications have been observed . over the last 10 years , we observed an increase in peer - reviewed papers on llr evaluating surgical and oncological results [ 3 , 4 ] . according to louisville statement and morioka consensus conference , llr is a feasible and safe procedure with surgical and oncological results similar to open surgery [ 3 , 4 ] . moreover , llr seems to have a better quality of life during the first year after surgery compared with open approach . at the beginning of the introduction of llr , one of the more frequent criticisms was that , because of a more challenging approach for anatomical segmentectomies , in most cases a non - anatomical resection is performed with thinner resection margins compared with open surgery . however , even in the presence of reduced surgical margins , oncological results in the short- and long - term follow - ups are the same such as open surgery especially for colorectal liver metastasis . however , a non - anatomical approach seems to have the same oncological results compared with anatomic resections but with better postoperative course due to the parenchymal sparing . according to the morioka consensus conference anatomical resections , including sectionectomy , segmentectomy and sub - segmentectomy , meant as parenchymal preserving resections of portal territories are considered complex procedures requiring identification of anatomical boundaries . these observations are even more true for a patient with previous open surgery and an sit with the double challenge related to the anatomic position of the liver and the posterior ( 7 ) segment involved . another challenging maneuver was the separation of the liver from the diaphragm ; the absence of any ligament made this part of the procedure very demanding to identify the correct plane from the diaphragm and the liver and minimize the bleeding . our routine approach for postero - lateral segments is with the patient in a supine position . this supine approach allows to have a better control of the pringle maneuver that should always be quickly available in difficult resections to perform the quickest laparotomy in the need to convert to open surgery ; however , in this particular case , we chose a lateral approach with a decubitus of 60 to have a more direct access to the left - sided liver . the mirror modality of ultrasonography , the quick control of the hilum if needed and the position have simplified the surgical approach in this patient . in conclusion , difficult llr resection can be safety made in experienced hands even in the presence of anatomical variations . at the same time , anatomical variations or the hypothesis of a
situs inversus totalis ( sit ) is a congenital condition consisting of a mirror image of transposition of the abdominal and thoracic organs occurring in about 1:5000 to 1:10 000 adults . 
 we report on a 60-year - old male with a single colorectal liver metastasis in the segment 7 . 
 the patients underwent a totally laparoscopic sub - segmentectomy . 
 intraoperative approach on a reverse posterior segment was difficult because of left - sided position of the liver . 
 postoperative course was uneventful and the patient was discharged after 5 days . to our knowledge , only a few cases of open liver resections in patients with sit have been published . 
 this is , therefore , the first case of laparoscopic liver resection for colorectal liver metastasis in a patient with sit . 
 we provide the readers with useful tips to perform minimally invasive liver surgery in such patients .