Case Report: Uroenteric Fistula in a Pediatric-en-bloc Kidney Transplant Manifests as Deceptive Watery Diarrhea and Normal Anion Gap Acidosis

Introduction: The diagnosis of a post–surgical uroenteric fistula can be challenging and may be delayed for months after symptoms begin. A normal anion gap metabolic acidosis has been reported in up to 100% of patients after ureterosigmoidostomy, and bladder substitution using small bowel and/or colonic segments. Here, we describe a rare case of a pediatric patient who developed a uroenteric fistula from the transplant ureters into the small bowel, after an en-bloc kidney transplantation resulting in profound acidosis and deceptive watery diarrhea.Case Presentation: The patient is an 8-year-old girl with end stage kidney disease (ESKD) secondary to focal segmental glomerulosclerosis. Through a right retroperitoneal approach, she underwent a right native nephrectomy and a pediatric deceased donor en-bloc kidney transplant including two separate ureters. One month later, she had a renal allograft biopsy for suspected rejection. During the week after the biopsy, she experienced abdominal pain followed by watery diarrhea and metabolic acidosis requiring continuous bicarbonate/acetate infusions. An extensive gastro-intestinal evaluation for the cause of the diarrhea including endoscopy was inconclusive. The urine output decreased to <500 ml daily; although, the kidney function remained normal. After 2 weeks of unexplained watery diarrhea a magnetic resonance urogram with contrast was performed which demonstrated extravasation of urine from both ureters with fistulization into the small bowel. She underwent corrective surgery which identified the fistulous tract, which was resected and both ureters were re-implanted. The diarrhea and acidosis resolved, and she has maintained normal renal allograft function for over 1 year.Conclusion: An important aspect in the early diagnosis of a uroenteric fistula is the sudden onset of severe hyperchloremic metabolic acidosis that results when urine is diverted into the intestinal tract. The mechanism is similar to that described in cases of urinary diversions and/or bladder augmentation using the intestine. Important diagnostic tools are the measurements of solute excretion and pH in the urine as compared to the “watery diarrhea” or bowel output.Summary: We describe a case of a uroenteric fistula in a pediatric-en-bloc kidney transplant patient that went undiagnosed for almost 3 weeks due to the deceptive nature of the watery diarrhea which was actually urine. A uroenteric fistula should be considered in the differential diagnosis of diarrhea and hyperchloremic metabolic acidosis as a complication of kidney transplant. The simultaneous comparison of stool and urine pH and solute excretions may lead to the diagnosis, appropriate imaging and surgical intervention.

Download Full-text

Case Report: Irreversible Watery Diarrhea, Severe Metabolic Acidosis, Hypokalemia and Achloridria Syndrome Related to Vasoactive Intestinal Peptide Secreting Malignant Pheochromocytoma

Frontiers in Endocrinology ◽

10.3389/fendo.2021.652045 ◽

2021 ◽

Vol 12 ◽

Author(s):

Aurelio Negro ◽

Ignazio Verzicco ◽

Stefano Tedeschi ◽

Nicoletta Campanini ◽

Magda Zanelli ◽

...

Keyword(s):

Weight Loss ◽

Metabolic Acidosis ◽

Vasoactive Intestinal Peptide ◽

Clinical Picture ◽

Chromogranin A ◽

Somatostatin Receptor ◽

Anion Gap ◽

Maximum Diameter ◽

Watery Diarrhea ◽

Hyperchloremic Metabolic Acidosis

BackgroundPheochromocytoma (PHEO) clinical manifestations generally mirror excessive catecholamines secretion; rarely the clinical picture may reflect secretion of other hormones. Watery diarrhea, hypokalemia and achlorhydria (WDHA) is a rare syndrome related to excessive secretion of vasoactive intestinal peptide (VIP).Clinical CaseA 73-year-old hypotensive man affected by adrenal PHEO presented with weight loss and watery diarrhea associated with hypokalemia, hyperchloremic metabolic acidosis (anion gap 15 mmol/l) and a negative urinary anion gap. Abdominal computed tomography scan showed a right adrenal PHEO, 8.1 cm in maximum diameter, with tracer uptake on 68GaDOTA-octreotate positron emission tomography. Metastasis in lumbar region and lung were present. Both chromogranin A and VIP levels were high (more than10 times the normal value) with slightly elevated urine normetanephrine and metanephrine excretion. Right adrenalectomy was performed and a somatostatin analogue therapy with lanreotide started. Immunostaining showed chromogranin A and VIP co-expression, with weak somatostatin-receptor-2A positivity. In two months, patient clinical conditions deteriorated with severe WDHA and multiple liver and lung metastasis. Metabolic acidosis and hypokalemia worsened, leading to hemodynamic shock and exitus.ConclusionsA rare case of WDHA syndrome caused by malignant VIP-secreting PHEO was diagnosed. High levels of circulating VIP were responsible of the rapidly evolving clinical picture with massive dehydration and weight loss along with severe hyperchloremic metabolic acidosis and hypokalemia due to the profuse untreatable diarrhea. The rescue treatment with lanreotide was unsuccessful because of the paucity of somatostatin-receptor-2A on VIP-secreting PHEO chromaffin cells.

Download Full-text

Hyperchloremic metabolic acidosis in the kidney transplant patient

Postgraduate Medicine ◽

10.1080/00325481.2019.1592360 ◽

2019 ◽

Vol 131 (3) ◽

pp. 171-175

Author(s):

Debora Avila-Poletti ◽

Leticia De Azevedo ◽

Candela Iommi ◽

Kristian Heldal ◽

Carlos G. Musso

Keyword(s):

Metabolic Acidosis ◽

Kidney Transplant ◽

Transplant Patient ◽

Kidney Transplant Patient ◽

Hyperchloremic Metabolic Acidosis

Download Full-text

The Use of the Urinary Anion Gap in the Diagnosis of Hyperchloremic Metabolic Acidosis

New England Journal of Medicine ◽

10.1056/nejm198803103181002 ◽

1988 ◽

Vol 318 (10) ◽

pp. 594-599 ◽

Cited By ~ 146

Author(s):

Daniel C. Batlle ◽

Miguel Hizon ◽

Eric Cohen ◽

Cory Gutterman ◽

Roop Gupta

Keyword(s):

Metabolic Acidosis ◽

Anion Gap ◽

Hyperchloremic Metabolic Acidosis

Download Full-text

P0002A NEW INSIGHT INTO THE MECHANISM OF HYPERCHLOREMIC METABOLIC ACIDOSIS IN KIDNEY TRANSPLANT RECIPIENTS: INCREASED POSTGLOMERULAR PERITUBULAR BLOOD FLOW IS A KEY CONDITION FOR THE DEVELOPEMENT OF CALCINEURIN INHIBITOR-INDUCED RENAL TUBULAR ACIDOSIS

Nephrology Dialysis Transplantation ◽

10.1093/ndt/gfaa142.p0002 ◽

2020 ◽

Vol 35 (Supplement_3) ◽

Author(s):

Shuzo Kaneko ◽

Joichi Usui ◽

Kazuhiro Takahashi ◽

Tomokazu Kimura ◽

Akio Hoshi ◽

...

Keyword(s):

Blood Flow ◽

Metabolic Acidosis ◽

Kidney Transplant ◽

Renal Tubular Acidosis ◽

Trough Level ◽

Transplant Recipients ◽

Kidney Transplant Recipients ◽

Renal Hemodynamic ◽

Hyperchloremic Metabolic Acidosis ◽

Renal Tubular

Abstract Background and Aims Hyperchloremic metabolic acidosis (HCMA) due to renal tubular acidosis is a common complication in kidney transplant recipients(KTR). Potential renal dysfunction, rejection, ischemia, persistent hyperparathyroidism, calcineurin inhibitors (CNIs), etc. have been identified as causes but have not been fully proven, and whether HCMA is a determinant of poor graft prognosis in KTR is still controversial. The purpose of this study is to elucidate the actual mechanism of HCMA in KTR. Method HCMA was defined as follows: i) simple strong ion difference (SID) Na-CL, which is the most dominant metabolic factor in physicochemical approach for acid-base balance, is 34 or less, or â…±) the alkalizing drugs have been started after the KT to correct HCMA. And all the cases of having diarrhea from mycophenolate mofetil(MMF), and gastroenterocolitis from cytomegalovirus infection were excluded. The study group consisted of 47 KTRs who underwent living-kidney transplantation(KT) at our hospital as well as a control group of 43 of the matched donors. Among them, a total of 26 KTRs received the renal hemodynamic studies which were based on urinary clearance of inulin and para-aminohippuric acid 1year after KT. 1) The incidence of HCMA in KTR at 3 months(3m) and 1 year(1y) after KT were examined. 2) To elucidate factors related to HCMA in KTR at 1y, we comprehensively examined factors and compared HCMA groups with non-HCMA groups; donor and recipient background (gender, age, body size), immunological factors, information on transplant surgery, salt and protein intake, effective buffering factors for extracellular body fluids such as albumin and hemoglobin, serum calcium and phosphate concentrations and their ratios, administration of renin-angiotensin system inhibitors and diuretics,Tac trough level and Banff score of each histopathological lesion in 1y biopsy. As for the 26 KTRs who received the renal hemodynamic studies, glomerular filtration rate (GFR), renal plasma flow (RPF), filtration fraction(FF) (GFR/RPF) and pre-/post-glomerular vascular resistance (pre-/postVR) calculated from the Gomez' equations were also analyzed. Results 1) The incidence of HCMA in the KTR at 3m was 51% (24/47), which was much higher than the 6.9% (3/43) in those donors (p<0.001), and the range of odds ratios (vs donor) adjusted by the background factors (age,gender, estimated GFR, albumin and hemoglobin) was 6.7-15.7 (p=0.0001-0.001). The incidence of HCMA in KTR at 1y decreased to 34%. 2)The univariate analysis of HCMA in KTR at 1y compared with non-HCMA showed an increase in RPF (p= 0.016), a decrease in post-VR (p= 0.003), and a decrease in FF (p= 0.0001), suggesting an increase in post-glomerular peritubular blood flow. In addition, the aah lesion score, an indicator of CNI vasculopathy, was also significantly higher in the HCMA (p = 0.015). There was no difference in Tac trough levels between HCMA and nonHCMA, and no independent factors were found by multivariate analysis. All cases with HCMA were classified into low post-VR (Fig.1). Furthermore, in low post-VR alone (n= 15), the Tac trough level at 1y was significantly higher in the HCMA (p= 0.002) (Fig.2). Conclusion In kidney transplant recipients, increased post-glomerular peritubular blood flow is a key condition for the development of CNI-induced renal tubular acidosis. The presence of HCMA suggests that it is probably not a serious condition, but rather a desirable hemodynamic state, however, more attention should be paid not to elevate CNI concentration levels in such conditions.

Download Full-text

Changes in the plasma anion gap during chronic metabolic acid-base disturbances

AJP Renal Physiology ◽

10.1152/ajprenal.1978.235.4.f291 ◽

1978 ◽

Vol 235 (4) ◽

pp. F291-F297 ◽

Cited By ~ 2

Author(s):

H. J. Adrogue ◽

J. Brensilver ◽

N. E. Madias

Keyword(s):

Metabolic Acidosis ◽

Metabolic Alkalosis ◽

Protein Concentration ◽

Anion Gap ◽

Acid Base ◽

Plasma Protein Concentration ◽

Basic Premise ◽

Hyperchloremic Metabolic Acidosis ◽

Large Groups

A basic premise in the utilization of the plasma anion gap in the assessment of acid-base disorders is that this parameter remains constant during hyperchloremic metabolic acidosis and metabolic alkalosis. Experimental data under in vitro conditions, however, cast serious doubt on this premise. The purpose of the present study was to characterize the plasma anion gap, estimated as (Na + K) - Cl + HCO3), in two large groups of dogs with graded degrees of chronic, HCl-induced metabolic acidosis or chronic, diuretic-induced metabolic alkalosis. The data indicate that the plasma anion gap decreases significantly in HCl acidosis and increases significantly in metabolic alkalosis; the predicted mean anion gap in animals with a plasma bicarbonate concentration of 10, 21 (normal), and 40 meq/liter approximated 13, 18, and 26 meq/liter, respectively. The observed variation in the plasma anion gap is interpreted as originating mainly from directional changes in the net negative charge of plasma proteins; these changes result from the titration process secondary to the altered plasma acidity and, in the case of metabolic alkalosis, from the additional effect of an increased plasma protein concentration.

Download Full-text

Normal "anion gap" (hyperchloremic) acidosis.

Clinical Chemistry ◽

10.1093/clinchem/31.2.309 ◽

1985 ◽

Vol 31 (2) ◽

pp. 309-313 ◽

Cited By ~ 4

Author(s):

R N Walmsley ◽

G H White

Keyword(s):

Metabolic Acidosis ◽

Anion Gap ◽

Common Condition ◽

Diagnostic Problem ◽

Hyperchloremic Acidosis ◽

Logical Approach ◽

Normal Limits ◽

Hyperchloremic Metabolic Acidosis ◽

Hospital Population

Abstract Hyperchloremic metabolic acidosis in which the anion gap is within normal limits is a common condition in the hospital population, and often presents a difficult diagnostic problem. We describe nine typical cases of this disorder and suggest a logical approach to its evaluation.

Download Full-text