EXPERIMENTAL AND CLINICAL TRANSPLANTATION

Objectives: Pancreas transplant is a major intra-abdominal operation, and in most cases the graft is placed in the right iliac fossa. At our center, preemptive appendicectomy is performed at the time of pancreas transplant to prevent any future risk in a complex transplant patient. The aim of this study was to review all histology reports from the removed appendices.

Materials and Methods: The histology reports from all incidental appendicectomies performed at pancreas transplant were reviewed.

Results: Between January 2001 and June 2016, 107 pancreas transplants were performed (86 simultaneous pancreas and kidney transplants, 11 pancreas after kidney transplants, and 10 pancreas transplants alone), and 65 appendix histology reports were available from this patient group. All were preemptive appendicectomies as none of the patients had symptoms to suggest acute appendicitis. Of the 65 appendix histologies, 43 (66.2%) were reported as normal. Twenty specimens (30.8%) showed fibrosis consistent with previous inflammation of the appendix, and 12 specimens (18.5%) showed fecal material in the lumen (1 due to an obstructing fecalith and another 2 showing luminal distension with feces). Three specimens (4.6%) showed lymphoid hyperplasia. There were 5 (7.7 %) unexpected findings upon histology. In review of histology reports, 1 patient had a 1.1-mm carcinoid tumor in an otherwise normal appendix, 1 had an Enterobius species worm infestation, 1 had focal endometriosis, 1 had crypt abscesses suggestive of inflammatory bowel disease, 1 had a metaplastic polyp, and 1 had melanosis coli of unknown clinical significance. There were no cases of overt acute appendicitis. No patients experienced a complication as a direct result of their appendicectomy.

Conclusions: A policy of routine appendicectomy at the time of pancreas transplant appears to be justified and safe.

Key words : Appendicitis, Preemptive surgery, Surgical complications

Pancreas transplant is a major abdominal operation. In most cases, the pancreatic allograft is transplanted into the right iliac fossa. Although success rates for this operation have improved since its inception in 1966,¹ there is a relatively high frequency of complications in the immediate postoperative period, which include anastomotic leaks, graft pancreatitis,² and local collections,³ all of which may potentially mimic appendicitis.⁴

In our center, the standard practice includes routine appendicectomy as part of the pancreas transplant procedure. If appendicitis were to present after pancreas transplant, it could cause diagnostic difficulties and removal of the appendix would not be an easy undertaking. Acute appendicitis in patients who have had abdominal solid-organ transplant procedures has been reported^5,6 and is associated with a higher complication rate than that shown in nontransplant patients.⁶ Incidental appendicectomy also has the benefit of avoiding the symptom-masking effects of steroid-based maintenance immunosuppression, increasing the likelihood that the presentation of acute appendicitis would be late, which could lead to perforation or mass formation.

Removal of a normal appendix at laparoscopy is a contentious issue. Surgeons advocating against appendicectomy cite the possible complication of a stump leak as grounds for not removing a normal appendix. If stump leakage is a complication to be avoided in a fit young adult, then it is surely a more feared complication in the immunosuppressed transplant patient. In this study, we reviewed our series of pancreas transplant recipients to evaluate the extent to which the theoretical benefits of incidental appendicectomy are realized in practice.

Materials and Methods

The original histology reports from incidental appendicectomies of pancreas transplant recipients in our center from 2001 to 2016 were reviewed to determine the frequency with which normal and abnormal appendices had been excised. Particular attention was paid to the histologic features felt to predispose the patient to a possible future attack of acute appendicitis. Evidence of previous inflammation and a current fecalith or lymphoid hyperplasia were considered to be risk factors for future acute appendicitis, but these are often hard to see macroscopically.

A database of pancreas transplant recipients was compiled to identify demographics and factors with the potential to influence appendiceal histology, such as current or previous use of peritoneal dialysis as a modality of renal replacement therapy. Subgroup analyses for the incidence of appendiceal fibrosis were formed for patients with previous peritoneal dialysis and patients with previous peritoneal dialysis-associated peritonitis.

Between 2001 and 2016, 107 pancreas transplants (65 male, 42 female; mean recipient age of 38.5 y [range, 15-59 y]) were performed at our institution. Of the 107 first transplants, 86 were simultaneous pancreas and kidney transplants, 11 were pancreas after kidney transplants, and 10 were pancreas transplants alone. Two were retransplants in patients who had previous simultaneous pancreas and kidney transplants. Appendix histology reports were available in 65 of the primary pancreas transplant patients. Of the 42 remaining patients, 8 had retroperitoneal transplant without appendicectomy, 7 had previous appendicectomy, and 2 had unknown reasons for appendix histology. None of the patients had symptoms to suggest acute appendicitis at the time of the transplant, and none experienced a complication as a direct result of their appendicectomy.

Histology in all pancreas transplant patients
Of 65 appendix histology reports, findings showed 43 (66.2%) indicated as normal, 20 (30.8%) with fibrosis consistent with previous appendicitis, and 12 (18.5%) with fecal material in the lumen (1 due to an obstructing fecalith and 2 due to luminal distension with feces). Three histology results (4.6%) indicated lymphoid hyperplasia, and 5 (7.7 %) indicated unexpected findings. One patient had a 1.1-mm carcinoid tumor in an otherwise normal appendix, 1 had an Enterobius species worm infestation in the appendix, 1 appendix showed focal endometriosis, 1 showed crypt abscesses suggestive of inflammatory bowel disease, 1 showed metaplastic polyp, and 1 had melanosis coli of unknown clinical significance.

Fibrosis in patients with peritoneal dialysis
Of the 8 recipients who had peritoneal dialysis, 4 recipients were still using peritoneal dialysis immediately before pancreas transplant, 1 was a pancreas after kidney transplant recipient, and 1 had converted to hemodialysis. Five transplant recipients had a history of previous peritoneal dialysis-associated peritonitis, including the patient who had converted to hemodialysis.

In the peritoneal dialysis group (n = 8), 2 patients (25%) had evidence of fibrosis in the appendicectomy histology report, compared with an incidence of 22.2% in the other pancreas transplant recipients (odds ratio 0.44; 95% confidence interval, 0.07-2.75; P = .661, Fisher exact test).

Only 1 of the 4 patients with previous peritoneal dialysis-associated peritonitis had fibrosis on histology (odds ratio vs no peritonitis 0.50; 95% confidence interval, 0.04-5.52; P = 1.000, Fisher exact test).

In this small series, histologic examination revealed significant abnormalities in the excised appendix specimens, with only 43 of 65 (66.2%) having histologically normal results. The 15 patients (23.8%) with luminal feces or lymphoid hyperplasia could reasonably be considered to be at risk of luminal obstruction and developing acute appendicitis.^7,8 In the study from Alaedeen and associates, 31% of appendicitis patients showed presence of fecaliths as confirmed on histology.⁹ For the 20 patients (29.2%) in our study with fibrosis consistent with previous appendicitis, an argument can be that these patients could have been at increased risk of future appendicitis. However, the fibrosis could have merely been a stigma of previous peritoneal dialysis-associated peritonitis, although in this series no association was observed between fibrosis and either peritoneal dialysis or previous episodes of peritoneal dialysis-associated peritonitis. The serendipitous finding of a fully resected 1.1-mm carcinoid in one appendix is extremely fortuitous in a patient about to be immunosuppressed.

Although right iliac fossa pain is one of the most frequent acute general surgical presentations, controversy remains on the diagnosis and surgical management of this clinical condition, with the emergence of diagnostic laparoscopy adding further fuel to this fire of surgical discourse. Although there is no debate on the need to remove the normal appendix during open appendicectomy, there are differing views on the optimal management of that found during diagnostic laparoscopy for acute right iliac fossa pain. Laparoscopy in the setting of such pain was initially advocated as a means to reduce the negative appendicectomy rate¹⁰ and thus reduce the risk of potential complications after appendicectomy such as wound infection, appendix stump leakage, and pelvic abscess. However, concerns remain about the accuracy of laparoscopic assessment of the appendix.¹¹ For example, inflammation without macroscopic changes can cause acute pain due to neuroproliferation and increased production of substance P and vasoactive intestinal peptide in the appendix.¹²

Verzaro and colleagues reported a single case of a 41-year-old patient presenting with acute appendicitis 9 years after simultaneous pancreas and kidney transplant.⁵ At the time of presentation, the patient had a peri-appendiceal abscess and a fecalith and thus was treated with percutaneous drainage and interval appendicectomy.

Savar and associates performed a wider review of 17 patients with appendicitis following organ transplant, including 2 patients with simultaneous pancreas and kidney transplant.6 Sixteen patients were diagnosed on computed tomography scanning and one by ultrasonography. All 17 patients in their series were treated by open appendicectomy, with postoperative complications reported in 4 patients (24%), including intra-abdominal abscess in 1 patient with appendicitis after simultaneous pancreas and kidney transplant. The mean hospital stay duration in this series was 7 days (range, 1-20 d).

Laparoscopic biopsies are conducted after pancreas and kidney graft; therefore, it is perhaps not inconceivable that at some point a laparoscopic appendicectomy will be described after pancreas transplant. Perhaps this would be more likely after a portal venous graft combined with enteric drainage as these are placed head up and encroach less in the right iliac fossa.¹³

An incidental appendicectomy was formerly considered a routine part of any laparotomy,¹⁴ although this practice is now considered controversial. In the early 20th century, Johns Hopkins gynecologist Howard Kelly, embarrassed at having missed an inflamed appendix during a laparotomy (which was subsequently removed by John Deaver), carried out a survey of American surgeons and found that most would not remove a completely normal appendix.¹⁵ Although sometimes considered old fashioned,

some authors have considered incidental appendicectomies to still have a role today.^16-18 The American College of Obstetricians and Gynecologists guidelines recommend prophylactic incidental appendicectomy in certain select circumstances, especially in patients who are less than 35 years old.¹⁹

Surgical complications are common after pancreas transplant,3 with relaparotomy being associated with a high risk of graft loss and mortality.²⁰ It is in this context that the role of incidental appendicectomy must be considered. In this study, we demonstrated a high rate of abnormal histologic findings, some suggesting an increased risk of future acute appendicitis. Therefore, we suggest that a policy of routine removal of the appendix during pancreas transplant is justified.

Volume: 17 Issue: 6 December 2019

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