the increasing adoption of laparoscopic or ( laparoscopic - assisted ) colorectal surgery as standard practice in colorectal cancer management has resulted in reduction in length of stay and improved patient experience . however , one complication , particular to laparoscopic but not to open surgery , is post - operative subcutaneous emphysema . although there have been numerous reports of this following laparoscopic upper gastrointestinal and gynaecological surgery , episodes of subcutaneous emphysema following other laparoscopic procedures such as extraperitoneal renal and colorectal surgery are few . subcutaneous emphysema of the scrotum developing 9 days post endoscopic retrograde cholangiopancreaticography has been reported , though there are no documentations of a significant post - operative delay in manifestation of this complication in any form of laparoscopic surgery . in a retrospective single centre review of 889 laparoscopic resections for colorectal cancer , subcutaneous emphysema was the most common intra - operative complication at 1.65% , though there were no reports of subcutaneous emphysema for patients undergoing left hemicolectomy in particular ( most were in anterior resection of the rectum ) and there were no such complications recorded for any laparoscopic colorectal patient in the post - operative period . in this report , we present the first case of massive subcutaneous emphysema which developed on the third day following laparoscopic left hemicolectomy . to perform the literature review for evidence for this case report , medline and embase were searched on 29 jan 2014 using the key terms : laparoscopy , colorectal cancer , subcutaneous emphysema ; works in all languages were considered . a 52-year - old female patient , with a large sigmoid tumour and associated mesenteric nodal mass , ( detected following colonoscopy and ct staging after referral from the national bowel screening programme , ) was admitted for an elective laparoscopic left hemicolectomy . of note , she had undergone extensive oral dental surgery ( apicectomy and retrograde filling ) for a recurrent dental pathology 2 months prior to her colorectal surgery . she was otherwise fit and well with no underlying lung pathology ( asa i ) . the patient underwent uneventful endotracheal intubation and received standard antibiotic prophylaxis consisting of gentamicin and metronidazole . she was placed in lithotomy ( slight trendelenburg ) position and 1014  mmhg carbon dioxide ( co2 ) pneumoperitoneum ( flow 20  l  min ) was maintained throughout ( for an estimated time of 130  min ) . the initial end tidal co2 ( etco2 ) at intubation was 4.1  kpa : it was documented as 5.5  kpa at the end of the procedure . the mean value of documented etco2 during pneumoperitoneum was 5.24  kpa ( sd    0.38 ) . standard laparoscopic dissection , aided by pneumoperitoneum , of tissue planes was carried out and the specimen was delivered through a self - retaining atraumatic retractor lining the extended midline wound . the anastomosis was performed laparoscopically using a circular stapled gun and air - leak test was negative . the patient recovered well post - operatively , with a good level of mobilisation and tolerating oral intake . on the third post - operative day , she developed surgical emphysema on her chest and neck , confirmed by a chest x - ray which showed a massive pneumoperitoneum and subcutaneous emphysema without definite evidence of pneumothorax . the only systemic abnormalities were : a non - compromising borderline tachycardia and oxygen saturations between 94 and 95% on air . further chest x - ray reported no significant interval change except for a suggestion of pneumomediastinum . a non - tender erythema of her right flank appeared , consistent with cellulitis except for lack of tenderness . crp rose to 367 ( white cell count remained normal ) and intravenous antibiotics were administered but discontinued after 2 doses , as a senior opinion determined there was no sign of sepsis . the subcutaneous emphysema resolved spontaneously and the patient was fit for discharge on day 6 . on clinic review , all symptoms had resolved and she was referred for adjuvant chemotherapy for a moderately differentiated adenocarcinoma , staged as iii ( t3n2m0 ) , positive for extramural vascular invasion . clinical manifestations of hypercarbia including subcutaneous emphysema developing during or very shortly after ugi procedures and tep procedures have been well documented . it has also been postulated that the incidence of surgical emphysema might be as high as 34% , if assessed radiologically via chest x - ray , after pelvic laparoscopic surgery ; mcalister instead stated that up to 56% of the patients who underwent laparoscopic cholecystectomy within the previous 24  h had subcutaneous emphysema on a computed tomography . hypothesised pathophysiology of subcutaneous emphysema includes tracking of gas along fascial planes from port sites ( increasing number of ports giving rise to increasing incidence of emphysema ) , or through diaphragmatic defects . factors increasing this risk include age of patient ( perhaps due to weaker tissues bonding fascial planes ) , increased number of ports , increased intra - abdominal gas insufflation pressures and long operating times , allowing increased absorption of carbon dioxide . we are unaware of an instance , prior to this case report , when 72  h have passed before the first signs of subcutaneous emphysema developing after a colorectal procedure . hypercarbia , although not confirmed by arterial blood gas sampling in our case , may explain some of this patient 's physiological derangement : a resultant acidosis could explain the tachycardia . a massive pneumoperitoneum may also have caused splinting of the diaphragm and decreased oxygen saturations . other cases of post - laparoscopic subcutaneous emphysema include an episode presenting after failed ercp in a patient after bariatic surgery , where gas was thought to pass through a weakened intestinal wall into the retroperitoneum ; an exploratory laparotomy for persistent leak excluded a perforation . risk factors for hypercarbia related injuries include an operating time greater than 200  min , age > 65 and six or more ports ) . subcutaneous emphysema has been shown to be more common when higher co2 insufflation pressures are used , though in this case a pressure of 10  mmhg was maintained throughout . possible explanations include a latent pocket of carbon dioxide in the abdominal wall which disseminated only later , after mobilisation of the patient ; a gas leak from the anastomosis , later resealed ; a small iatrogenic mucosal disruption , resulting in retroperitoneal air leak , settled spontaneously . on the other hand , an iatrogenic airway injury or a pneumothorax appears unlikely on account of clinical and radiological findings . in our patient , the observations remained stable until the development of subcutaneous emphysema on the third post - operative day . after this time although arterial blood gases were not deemed necessary , retrospectively this new tachycardia could have been a response to hypercarbia , following delayed absorption of carbon dioxide . written informed consent was obtained from the patient for publication of this case report and accompanying images . a copy of the written consent is available for review by the editor - in - chief of this journal . aj , up and se performed a search of the literature and wrote the report , under supervision of ajw .