Although the fundamental principles of surgery continue to apply, it is important to recognize the differences that exist between the transplanted patients chronically immunosuppressed and the general population. Transplanted patients have unquestionably more medical problems, particularly in regard to cardiovascular diseases. Moreover, the immunosuppression regimen can mask the presenting signs and symptoms of many disease processes, as well as interfere with the patient management for transplant-unrelated surgical procedures in terms of risk of drug interactions, adverse effects, wound healing, and postoperative complications [2].

In general, preoperative considerations are independent of the type of transplant and should start by assessing the underlying cardiac status of the patient [3]. Cardiovascular disease complications are a major cause of morbidity and mortality among transplanted patients, and particularly in renal-transplanted patients; thus, the major concern is the risk of a perioperative cardiovascular event [3–7]. It is noteworthy that immunosuppression can be considered a cardiac risk factor as least as important as hypertension or hyperlipidemia [4, 7, 8]. The administration of β-blockers to decrease perioperative cardiac morbidity should be considered in any transplanted patient about to undergo a major general surgical procedure [9].

Preoperative antibiotics have not been extensively studied in transplanted patients undergoing general surgery. However, transplanted patients should always be considered “at risk,” since infection is an inevitable consequence of life-long immunosuppression. Current immunosuppressive regimens typically consist of two phases: induction phase and maintenance therapy. There are no uniform induction regimens, but most transplant centers use either high doses of conventional immunosuppressive agents, or polyclonal or monoclonal antibodies directed against T-cell antigens (more common in heart, lung, and kidney transplantation). Maintenance immunosuppression generally consists of a drug combination therapy, involving corticosteroids, calcineurin inhibitors, antiproliferatives, and mTOR inhibitors. With the standardization of immunosuppressive protocols, a pattern of susceptibility has been described, which appeared to be dependent on the dose, duration, nature, and temporal sequence of immunosuppressive therapy [10]. Thus, prophylactic antibiotics are virtually indicated in all cases, including clean cases, and during both induction and maintenance phases. As usual, broader spectrum coverage to include Gram-positive and Gram-negative bacteria is warranted for intra-abdominal procedures, given by infusion within 1–2 h before the surgical incision [3, 11].

Because most transplanted patients are maintained on chronic corticosteroids as part of their immunosuppressive regimen, the possibility of adrenal insufficiency is often raised when these patients develop emergent problems requiring surgical intervention. However, adrenal insufficiency has become less and less common, because the current doses of steroids used for the maintenance therapy have been markedly reduced compared with previous standards. As a consequence, the practice of administering a prophylactic supraphysiologic dose of corticosteroids peri-operatively (the so-called stress dose) appears to be unnecessary in most of the cases [12].

Finally, it must be considered that immunosuppressive therapy affects tissue integrity and wound healing. In particular, the use of glucocorticoids, even at low doses, is associated with consequent enhanced friability of skin, superficial blood vessels and intestinal wall, making a cautious and delicate handling of the tissues cardinal to avoid postoperative wound-healing complications. Moreover, the use of nonabsorbable sutures as well as keeping skin staples in place two to three times longer than usual are recommended in transplanted patients [3].

Transplanted patients represent only a small percentage of individuals seen in trauma centers, but they present with a peculiar condition in which the inflammatory responses following trauma injuries may be blunted by the long-standing immunosuppression [13]. Although there is a paucity of data in the literature, traumas in heart-transplanted patients have been generally associated with good graft outcomes (which is infrequently injured), whereas an increased potential for rejection has been reported in renal transplant patients [14]. Moreover, a higher rate of skeletal fracture has been suggested in transplanted patients compared to nontransplanted patients [15], while no increased risk of infection was observed in a recent retrospective study conducted in a large transplantation and Level I trauma center [16]. Only in few cases, mild damage to the grafts was radiographically observed, but patients did not manifest signs and symptoms of graft failure [16]. These data are encouraging and suggest that transplanted grafts are not at increased risk for injury following trauma.

Gastrointestinal emergencies are highly frequent in transplanted patients and are associated with considerable morbidity and mortality [17–20]. The clinical presentation may be subtle or completely unexpected due to the masking nature of immunosuppression, thus confirmatory imaging tests (e.g., computed tomography) should not be delayed in these patients. In general, treatment should be aggressive, since intestinal healing, as for any surgical sites, will be impaired and infection rates high. Surgery is most of the time the preferable treatment, since transplanted patients are not good candidates for medical therapy in case of appendicitis, perforated ulcer, complicated diverticulitis, or any other condition that will require high degree of physiologic wound-healing functions to repair without intervention.

Acute appendicitis after solid organ transplantation is a rare event, as documented by few case reports in the literature [21–23]. However, appendicitis in transplanted patients is commonly associated with delayed diagnosis, misdiagnosis, and complicated appendicitis, including rupture and gangrene. Moreover, if not aggressively treated, it can lead to substantial morbidity in the clinical setting of chronic immunosuppression. Laparoscopic appendectomy appeared to be safe and feasible in kidney-, pancreatic-, and liver-transplanted patients, with intraoperative and postoperative outcomes similar to those procedures carried out in nontransplanted patients [21]. Conversely, some authors suggested conservative treatment, like radiological drainage, in transplanted patients with appendiceal abscesses to transform an emergency operation into an elective one in favor of a decreased morbidity [24]. However, the potential benefits of a medical management need to be balanced with the risks associated with delayed surgery in an immunosuppressed patient.

A higher incidence of diverticulitis, as well as more virulent disease, and more complicated recurrences are reported in immunocompromised and transplanted patients [25, 26]. The diagnosis and treatment of diverticulitis after solid organ transplantation are challenging, since maintenance immunosuppressive therapies may mask presenting symptoms and impair the ability to contain the infective process. This predisposes patients to an increased incidence of free peritoneal perforation or complicated disease in comparison to immunocompetent patients [25]. However, the incidence of colonic perforation after transplantation is rather low, involving 1–2 % of cases. Diverticulitis is the most common cause of perforations, followed by ischemic colitis and cytomegalovirus colitis, which can co-exist. Morbidity and mortality following emergency colectomy for complicated diverticulitis in immunocompromised patients are higher than those of immunocompetent individuals, ranging between 20 and 30 % [26, 27]. On the contrary, postoperative outcomes of elective procedures seem no different from those observed in nontransplanted patients [26]. The significant morbidity following sigmoid diverticulitis among transplant recipients has prompted consideration of pretransplant prophylactic surgery for patients with sigmoid diverticulosis proven by colonoscopy. In fact, this is a feasible approach only for kidney transplant candidates, since patients awaiting heart, lung, or liver transplantation are generally too sick to tolerate any major surgical procedures. Moreover, the incidence of sigmoid diverticulitis in transplant recipients (estimated at 1 %) may be too low to warrant prophylactic surgery as a routine protocol. Hartmann’s procedure is the treatment of choice for diverticulitis complicated by perforation (Hinchey III and IV). The rate of stoma closure (i.e., Hartmann’s reversal) observed in transplanted patients is comparable to that reported in the literature for immunocompetent patients [26, 28].

Peptic ulcer disease in transplanted patients represents another frequent gastrointestinal emergency associated with high mortality rate (up to 40 %). However, thanks to a deep screening of transplant candidates, and an active treatment of pre-existing disease with H₂-receptor antagonists or proton pump inhibitors, the incidence of peptic ulcer disease has drastically decreased. The relationship of corticosteroids with peptic ulcer disease is unclear; it appeared to be exacerbated by the immunosuppression regimen rather being a direct complication of steroid therapy. The prevalence of Helicobacter pylori infection in solid-organ transplant recipients is similar to that in nontransplant controls, and the incidence of H. pylori-related peptic ulcer disease and mucosa-associated lymphatic tissue lymphoma does not increase under the immunosuppressive treatment after transplantation [29]. Considering the excellent results of nonoperative ulcer therapy in transplanted patients, surgery should be limited to complicated or perforated cases. However, an early diagnosis and a prompt treatment are the key of success; thus, an exploratory surgery (either by laparoscopy or laparotomy) in patients with uncertain diagnosis might prove to be a better approach than wait for the symptoms to be aggravated.

Biliary tract diseases are among the most common problems in transplanted patients, with a prevalence of cholelithiasis as high as 30–40 % [17, 30, 31]. Despite actual controversies, this seems to be related to cyclosporine-induced perturbation of bile composition resulting in an increased prevalence of biliary stones formation [32, 33]. Clinically, the incidence of symptomatic cholelithiasis posttransplant is frequently observed in cardiac, lung, kidney, and kidney–pancreas-transplanted patients [31, 34–36]. Emergency surgery for acute biliary tree complications has been associated with high morbidity (up to 47 %) [30, 34] and mortality rates (up to 29 %) [30, 31], and thus, a prophylactic cholecystectomy in patients awaiting transplantation has been proposed as a strategy to avoid symptomatic gallstone diseases later on [37, 38]. However, this is still under debate and not routinely performed also because an emergency cholecystectomy can be highly problematic in patients with end-stage diseases.

Transplanted patients presenting with biliary symptoms should be treated promptly and aggressively. Laparoscopic cholecystectomy can be performed safely in lung- and kidney-transplanted patients, with outcomes that appeared comparable to nontransplanted populations [36, 39]. Conversely, heart-transplanted patients seem to be at higher risk when an emergency cholecystectomy is required, independently of the surgical approach (i.e., laparoscopic vs. open surgery) [30, 40], whereas pancreas-transplanted patients may require specific technical modifications in the laparoscopic cholecystectomy, which need to be carefully evaluated preoperatively. Finally, biliary problems in the liver-transplanted patient, such as strictures, cholangitis, abscesses, and liver bilomas, should be better referred to a center with experience in liver transplantation.

Ultimately, transplanted patients under immunosuppressive regimens are prone to wound healing impairment and secondary incisional hernia when exposed to surgery. Although no specific data are available about incisional hernias in transplanted patients subsequently undergoing emergency general surgical procedures, its incidence is expected to be higher than in the general population. In the literature, incisional hernias in liver-transplanted patients have been reported to be as high as 17 %, likely consequent to effects of immunosuppression, malnutrition, and end-stage liver disease [41]. The incidence of incisional hernia in renal-transplanted patients is lower, ranging from 3 to 4 % [42]. Several reports support that hernias repair by placement of prosthetic materials is safe also in transplanted patients despite the increased risk of infections [43, 44].