Advances in Peritoneal Dialysis, Vol. 22, 2006

Gross Calcification of the

Small Bowel in a

Continuous Ambulatory

Peritoneal Dialysis Patient

with Sclerosing Peritonitis

We present here the case of a continuous ambulatory

peritoneal dialysis (CAPD) patient who developed

sclerosing calcifying peritonitis with gross macro-

scopic calcification of the small bowel, a rare and life-

threatening complication of sclerosing peritonitis.

A 40-year-old female had been on CAPD for

7 years. A peritoneal biopsy during an open chole-

cystectomy for cholelithiasis showed sclerosing peri-

tonitis, but the patient refused to change dialysis

modality. She remained free of symptoms for 3 years,

but then was admitted with cloudy effluent, abdomi-

nal pain, and referred pain to the left shoulder. A white

blood cell count showed 25,000 cells/µL, and a peri-

toneal cell count showed 1000 cells/µL. An abdomi-

nal computed tomography scan was nondiagnostic.

The patient was started on intraperitoneal antibiot-

ics, but 3 days later she was taken for surgery be-

cause of acute abdomen.

Laparotomy revealed a tanned and thickened peri-

toneum and a small bowel with significant fibrosis

and foci of calcification on the antimesenteric sur-

face. Enterectomy and primary anastomosis was per-

formed. Pathology revealed extensive mural fibrosis,

calcium deposition, and localized inflammatory infil-

tration of the small bowel. The patient developed an

anastomotic leak and, despite a second operation, died

in the intensive care unit from septic shock.

Although some authors report successful outcomes

in similar cases by using surgery or other treatments

(parenteral nutrition, immunosuppression), or both,

we urgently recommend that, if sclerosing calcifying

peritonitis is diagnosed, the patient be switched

promptly to hemodialysis.

Antigoni Poultsidi,1 Vassilios Liakopoulos,2 Theodoros

Eleftheriadis,2 Sotirios Zarogiannis,2 Sofia Bouchlariotou,2

Ioannis Stefanidis2

Key words

Sclerosing peritonitis, ectopic small-bowel calcifi-

cation

Introduction

Sclerosing peritonitis is a rare but serious complica-

tion of continuous ambulatory peritoneal dialysis

(CAPD). In all patients on long-term CAPD, a vari-

able degree of diffuse peritoneal fibrosis (“simple scle-

rosis”) has been documented and is usually clinically

silent. In simple sclerosis, there are no histologic

changes involving inflammation or severe calcifica-

tion (1).

If sclerosing peritonitis ensues, the histologic pic-

ture becomes more dramatic. The basic disorder of

sclerosing peritonitis is an inflammatory process that

affects the parietal and visceral peritoneum diffusely.

Acute and chronic inflammatory changes are both

observed, and vasculopathy—including vascular oc-

clusion and potentially vascular ossification—is evi-

dent. These processes result in a spectrum of

macroscopic changes ranging from simple parietal

peritoneal opacification with or without tanned peri-

toneum to extensive mural fibrosis of the small bowel,

adhesions, or encapsulating cocoon, constituting the

separate entity “sclerosing encapsulating peritonitis”

(1,2). Clinical presentation includes reduced ultrafil-

tration capacity, dysfunctional peristalsis of the intes-

tine, and luminal obstruction. Although rare, small-bowel

perforation has also been reported (3).

Another entity with extensive peritoneal calcifi-

cation occurring alone or in combination with encap-

sulating peritonitis has been characterized as

“calcifying peritonitis” (4). Parietal peritoneum cal-

cification is usually a prerequisite.

Here, we report a rare case of sclerosing peritoni-

tis and small-bowel macroscopic calcium deposition

From: 1Department of Surgery and 2Department of Neph-

rology, Medical School, University of Thessaly, Larissa,

Greece.

Poultsidi et al. 105

without obvious [either macroscopic or computed

tomography (CT) finding] peritoneal calcification as

would be expected.

Case report

A 40-year-old woman with end-stage renal disease

was admitted with fever (38.8°C), generalized ab-

dominal pain, and referred pain to the left shoulder.

The patient had been on dialysis for 12 years:

5 years initially on hemodialysis, and the last 7 years

on CAPD with lactate-buffered solutions. Her medi-

cal history included systemic lupus erythematosus

diagnosed 18 years earlier, an appendectomy, 2 cae-

sarian sections, and an open cholecystectomy per-

formed 5 years earlier. A peritoneal biopsy at the time

of the cholecystectomy showed changes of scleros-

ing peritonitis, but the patient was still asymptomatic

and chose to remain on CAPD. During the 3 years

preceding admission, she had been diagnosed with

secondary hyperparathyroidism (intact parathyroid

hormone level 500 pg/mL), but she sustained normal

serum calcium levels (9.6 mg/dL). Her serum phos-

phorus was 4.3 mg/dL. By a standard peritoneal equili-

bration test, the patient was classified as a

high-average transporter. She was taking sevelamer,

vitamin D, and amlodipine as an antihypertensive.

On admission, laboratory studies revealed a white

blood cell count of 25,000 cells/mL with 88% poly-

morphonuclear cells, a serum amylase level of 118 U/L

(reference 0 – 90 U/L), and a peritoneal fluid amylase

of 221 U/L, with normal liver function tests.

An abdominal CT scan was performed, but was

nondiagnostic. At that point, the patient’s dialysate

effluent became cloudy, and so the symptoms were

attributed to CAPD-related peritonitis. A peritoneal

cell count showed 1000 cells/µL. It was the patient’s

third peritonitis episode; the first two had been cul-

ture-negative. Oral intake was stopped, and the patient

was treated initially with intraperitoneal ceftazidime,

tobramycin, and vancomycin, plus intravenous

cefoxitin. Three days later, the patient was still

febrile, and the peritoneal effluent became bloody.

The white blood cell count remained elevated

(37,000 cells/mL). Acute abdomen was diagnosed,

and the patient was taken for surgery.

Laparotomy revealed a tanned and thickened pa-

rietal peritoneum with macroscopic changes of scle-

rosing peritonitis and a bloody fluid collection. Much

of the small bowel—120 cm, starting 20 cm from the

ligament of Treitz—was also tanned and thickened

and showed no peristalsis. The sigmoid colon and rec-

tum showed the same macroscopic changes. The

antimesenteric surface of the small bowel showed

obvious calcium deposition, with crystals forming at

distant foci (Figure 1). The mesentery was thickened,

but no adhesions or encapsulating sheath formations

were seen. There were no signs of perforation.

The most affected part of the small bowel was

resected, and primary anastomosis was performed.

The peritoneal (Tenckhoff) catheter was removed, and

the peritoneal cavity was washed out with large

amounts of normal saline. A soft drain was inserted

adjacent to the anastomosis.

The patient had a dramatic recovery during the

first postoperative days. A central venous line was

inserted for hemodialysis. Her white blood count

dropped to normal (8000 cells/mL). Unfortunately,

on the 8th postoperative day, she developed an

anastomotic leak and fecal peritonitis. A second

operation was performed, and both ends of the

small bowel were brought out as a stoma. The

patient died 5 days later in the intensive care unit

from septic shock.

The pathology report revealed extensive mural

fibrosis, calcium deposition with macroscopic

granular appearance, and localized inflammatory

infiltration of the small bowel. Severe vasculopathy,

with basement membrane proliferation and exten-

sive granular deposition of calcium in branches of

the superior mesentery artery, was observed. The

mesentery was thickened and showed changes of

acute inflammation (Figures 2 and 3).

FIGURE 1 Resected bowel, surgical specimen. Arrows point to

areas of calcification.

106 Small-Bowel Calcification in Sclerosing Peritonitis

Discussion

Calcium deposition as a possible complication of long-

term CAPD was first described in 1987 by Marichal

et al. (5), and the nosological entity was separately

named “calcifying peritonitis” (6). In most cases only

parietal peritoneum is involved. On visceral involve-

ment, calcification is described as plaques of calcium

or eggshell calcification (6,7).

The pathogenesis of calcifying peritonitis is still

unclear. However, some important predisposing fac-

tors of this ectopic ossification have been recognized

(8). Sclerosing peritonitis (but not simple sclerosis)

is consistently present in all cases of reported calcify-

ing peritonitis. In sclerosing peritonitis, the inflam-

matory process affects the peritoneum diffusely,

resulting in substitution of the normal mesothelium

by an acellular band of hyalinized collagen. There is

also marked thickening of microvessel walls and nar-

rowing of the vascular lumen (2,4,8,9). As the pro-

cess evolves, fibrosis may involve the outer wall of

the small bowel, with eventual obliteration of the lon-

gitudinal muscle layer and the myenteric plexus. As a

result, the peritoneum and the small bowel both lose

their normal texture and become tanned, thickened,

and wrinkled. The small intestine may lose its peri-

stalsis and become completely dysfunctional (2).

Normal mesothelium acts as a protective barrier

against all offending agents. The hypothesis for cal-

cifying peritonitis is that, when the protection of

mesothelium is lost, inflammatory or other factors may

stimulate stem cells (mesoblasts) to differentiate into

osteoblasts that are responsible for ectopic calcifica-

tion (8). Sclerosing peritonitis was present in our

patient for the last 5 years.

Furthermore, one very important pathogenetic fac-

tor both for sclerosing peritonitis and the development

of calcifying peritonitis is CAPD-related peritonitis

(2,8). Most patients with reported calcifying perito-

nitis have a medical history of multiple episodes of

CAPD peritonitis, although sclerosing encapsulating

peritonitis may occasionally occur in the absence of

such episodes (2,10). Cox et al. reported a case of

gross peritoneal calcification with no history of fre-

quent peritonitis episodes, but with extensive scle-

rosing peritonitis (11). Other trigger factors that have

been incriminated include the use of acetate-contain-

ing dialysate, hypertonic glucose solutions, beta-

blockers, and lately, chlorhexidine in alcohol

sterilizing sprays (2,4). Our patient had no history

of beta-blocker administration, and she used povi-

done iodine as an antiseptic.

It has been postulated that secondary hyperpar-

athyroidism plays a major role in the pathogenesis of

calcifying peritonitis, which could be considered a

case of ectopic calcification. A systemic calciphylaxis

model has been proposed, in which tissues respond to

sensitizing agents with inappropriate calcium deposi-

tion—one of the main sensitizing factors being par-

athyroid hormone. In some reports, patients had severe

secondary hyperparathyroidism (6,7), and in one, evi-

dence of metastatic soft tissue calcification was also

present (6). However, in other cases, peritoneal cal-

cification was not accompanied by abnormalities

of calcium and phosphate metabolism (11), or the

FIGURE 2 Calcification plaques in the serosa and the muscular

layer of the small bowel.

FIGURE 3 Branch of the superior mesenteric artery, showing

granular calcium deposition (arrow).

Poultsidi et al. 107

calcium and parathyroid hormone status was

unknown (3,12). Our patient sustained normal Ca and

Ca×P levels, and her parathyroid hormone level was

not much elevated.

Management of sclerosing calcifying peritonitis

is a difficult challenge. Some authors suggest perform-

ing abdominal radiography or a CT scan as a screen-

ing test on all patients who have been on CAPD for

more than 5 years (13). Verbanck et al. (3) also report

the use of ultrasound (3.5 MHz curved-array trans-

ducer) to detect gross calcifications and thickening of

the bowel. If such signs are detected, they suggested

that the patient should be switched promptly to he-

modialysis, because if calcifying peritonitis develops,

the outcome is extremely poor.

Total parenteral nutrition for a variable period of

time is inevitably required to avoid malnutrition and

sepsis and to rest the intestine (4,12). Surgery is a late

option with high morbidity. The surgeon may be faced

with a last-resort decision to perform extensive and

inappropriate resections and anastomoses. Removing

(peeling) the calcium plaques and the fibrous sheath

or adhesions (enterolysis) to reveal a healthier bowel

and peritoneum may not be feasible and may result in

bowel perforation. However, some authors have re-

ported about 8 patients treated successfully with sur-

gical enterolysis (13). Lately, immunosuppressive

therapy with corticosteroids or other immunosuppres-

sive agents has been proposed before and after sur-

gery to avoid recurrence and further deterioration.

However, more research is needed in this field.

Conclusions

Sclerosing calcifying peritonitis, although rare as a

complication of long-term CAPD, is detrimental. We

therefore recommend that, if sclerosing peritonitis is

diagnosed, the patient should be closely monitored

and promptly switched to hemodialysis.

References

1 Garosi G, Di Paolo N, Sacchi G, Gaggiotti E. Scle-

rosing peritonitis: a nosological entity. Perit Dial Int

2005; 24(Suppl 3):S110–12.

2 Mactier RA. The spectrum of peritoneal fibrosing

syndromes in peritoneal dialysis. Adv Perit Dial

2000; 16:223–8.

3 Verbanck JJ, Schoonjans RS, Vandewiele IA, Segaert

MF, Crolla DP, Tanghe WR. Sclerosing peritonitis

with gross peritoneal calcification and abdominal

wall abscess secondary to bowel perforation:

ultrasonographic appearance. J Clin Ultrasound 1997;

25:136–40.

4 Rigby RJ, Hawley CM. Sclerosing peritonitis: the ex-

perience in Australia. Nephrol Dial Transplant 1998;

13:154–9.

5 Marichal JF, Faller B, Brignon P, Wagner D, Straub P.

Progressive calcifying peritonitis: a new complication

of CAPD? Report of two cases. Nephron 1987;

45:229–32.

6 Fletcher S, Gibson J, Brownjohn AM. Peritoneal cal-

cification secondary to severe hyperparathyroidism.

Nephrol Dial Transplant 1995; 10:277–9.

7 Francis D, Busmanis I, Becker G. Peritoneal calcifi-

cation in a peritoneal dialysis patient: a case report.

Perit Dial Int 1990; 10:237–40.

8 Di Paolo N, Sacchi G, Lorenzoni P, Sansoni E,

Gaggiotti E. Ossification of the peritoneal membrane.

Perit Dial Int 2004; 24:471–7.

9 Araki Y, Hataya H, Tanaka Y, et al. Long term perito-

neal dialysis is a risk factor of sclerosing encapsulat-

ing peritonitis for children. Perit Dial Int 2000;

20:445–51.

10 Hauglustaine D, van Meerbeek J, Monballyu J,

Goddeeris P, Lauwerijns J, Michielsen P. Sclerosing

peritonitis with mural bowel fibrosis in a patient on

long-term CAPD. Clin Nephrol 1984; 22:158–62.

11 Cox SV, Lai J, Suranyi M, Walker N. Sclerosing peri-

tonitis with gross peritoneal calcification: a case re-

port. Am J Kidney Dis 1992; 20:637–42.

12 Kawanishi H, Harada Y, Sakikubo E, Moriishi M,

Nagai T, Tsuchiya S. Surgical treatment for sclerosing

encapsulating peritonitis. Adv Perit Dial 2000;

16:252–6.

13 Stafford–Johnson D, Wilson T, Francis I, Swartz R.

CT appearance of sclerosing peritonitis in patients on

chronic ambulatory peritoneal dialysis. J Comput As-

sist Tomogr 1998; 22:295–9.

Corresponding author:

Ioannis Stefanidis, MD, Associate Professor of Inter-

nal Medicine/Nephrology, University of Thessaly,

School of Medicine, Papakyriazi 22, Larissa 41222

Greece.

E-mail:

stefanid@med.uth.gr