The role of laparoscopy in the identification and management of missing accessory spleens after primary splenectomy: A case report and literature review.

We present a 7-year-old boy with recurrent thrombocytopenia after primary laparoscopic splenectomy for immune thrombocytopenia (ITP). Imaging modalities (ultrasound, computed tomography scan, and scintigraphy) revealed two accessory spleens while the subsequent second laparoscopy revealed 11, which were successfully removed. The relevant medical literature is reviewed, and the value of laparoscopy for chronic ITP is highlighted.

INTRODUCTION

Patients with immune thrombocytopenia (ITP) who relapse after primary splenectomy should be evaluated for the presence of accessory spleens. The clinical efficacy of a supplementary accessory splenectomy (open or laparoscopic) has varied between clinical studies of adults, and there are few data regarding its safety and efficacy in children with chronic ITP.[123]

Herein, we describe a 7-year-old boy with recurrent thrombocytopenia after primary laparoscopic splenectomy for chronic ITP. Abdominal ultrasound (US) and computed tomography (CT) scan of the abdomen revealed only one accessory spleen, preoperative scintigraphy revealed two accessory spleens, but the subsequent second laparoscopy revealed 11 residual accessory spleens, which were successfully removed.

CASE REPORT

A 7-year-old boy underwent laparoscopic splenectomy due to chronic ITP that was refractory to conservative treatment. The spleen was removed intact within a retrieval bag, measured 11 cm × 5.5 cm × 2.5 cm and weighed 71 g. A meticulous laparoscopic search of all possible location for accessory spleens including the hilar region, the splenorenal ligament, the greater omentum, the retroperitoneal region surrounding the tail of the pancreas, the splenocolic ligament, and the mesentery of the large and small intestines was negative. In the immediate postoperative period, his platelet counts remained normal, up to a peak of 750,000/μl on the 5th postoperative day, and examination of the peripheral blood via a smear revealed abundant Howell-Jolly (HJ) bodies within the erythrocytes.

The patient relapsed 4 months after the laparoscopic splenectomy, developing petechiae and ecchymoses, and was found to have a platelet count of <20,000/μl. A meticulous examination of a peripheral blood smear revealed the absence of HJ bodies, suggestive of residual splenic function. Ultrasonography of the upper abdomen revealed an egg-shaped mass in the anatomic area of the splenic bed measured 3.6 cm × 2.9 cm × 5.2 cm. A CT scan of the abdomen confirmed the existence of this globular mass suggestive of the presence of a secondary accessory spleen. For the next few months, the patient was retreated on demand with immunosuppressive drugs. Because of worsening hemorrhagic manifestations, the patient's family consented for laparoscopic accessory splenectomy. 99mTechnetium-sulfur colloid single-photon emission CT (SPECT) was performed before the reoperation, which revealed two areas of residual splenic tissues: A large area in the anatomic area of the spleen that corresponded to the mass seen previously by US and CT scan and a smaller inferior to the first [Figure 1].

Figure 1

99mTechnetium-sulfur colloid-based scanning reveals two areas of residual splenic tissues in the anatomic area of the splenic bed (arrows)

During the operation, nine smaller accessory spleens were unexpectedly found along the greater omentum in various positions, in addition to the two accessory spleens observed preoperatively on SPECT. All of these small nodules as well as the larger one were successfully removed laparoscopically using ultrasonically activated coagulating shears (Ultracision, Ethicon Endo-Surgery, Surgical Corp. Cincinnati, Ohio, USA). Histological evaluation confirmed that all of the specimens were splenic tissues, with the ten smaller accessory spleens having dimensions ranging from 0.5 cm to 5.5 cm while the larger one measured 5.5 cm × 7.5 cm × 2.5 cm and weighed 25 g.

The patient was discharged on the 5th postoperative day in excellent clinical condition and remains with normal platelet counts for >36 months after surgery.

DISCUSSION

Splenectomy is considered as an effective treatment option for patients with chronic ITP since this will result in the thrombocytopenia resolving or improving in approximately 70% of cases.[4] It has been estimated that approximately 18% of patients who have a good platelet response to primary splenectomy for ITP will develop a clinical recurrence due to the presence of residual splenic tissue.[5] Three etiologies have been proposed for the development of residual splenic tissue after primary splenectomy: (i) Functioning accessory spleens missed at the time of the initial surgery, (ii) hypertrophy of splenic tissue that leaked from organ rupture during open splenectomy and/or from the retrieval bag at the time of laparoscopic surgery, and (iii) compensatory postoperative hypertrophy of splenic rests that are too small to visualize. In the present case, the large number of accessory spleens raises the possibility of splenic tissue spillage into the abdominal cavity after the initial splenectomy. However, an exhaustive review of the video recording of the initial laparoscopic splenectomy did not show any presence of splenuculi or a leak of splenic tissue from the retrieval bag. Moreover, the pathologic examination of the spleen confirmed it was removed intact and without a rupture. Therefore, compensatory hypertrophy of tiny pieces of splenic tissues missed at the time of the initial laparoscopic splenectomy was probably the cause of recurrence in our patient. This conclusion is supported by the initial postoperative appearance of HJ bodies within the erythrocytes in the blood smear that disappeared over time; compensatory hypertrophy of the residual splenic tissues that acquired sufficient functionality must therefore have occurred.

SPECT has been proposed as the most accurate way of detecting functioning residual splenic tissue before reoperation.[6] Nevertheless, this technique in our case was not able to detect all the surgically removed accessory spleens, many of whom were <1 cm within the greater omentum.

Although it has been suggested that the laparoscopic identification of residual splenic tissue has a lower success rate due to the loss of tactile feedback,[7] we consider that the resolution and magnification provided by laparoscopy allowed the identification and resection of all residual splenic tissues, some of which would probably not have been discovered in an open laparotomy since three of them measured only 0.5 cm.

A search of the English-language literature yielded only a few cases of accessory splenectomy in childhood. In all these cases, the accessory splenectomy performed via open laparotomy and to the best of our knowledge, our patient is the first child to have been described in whom accessory splenectomy accomplished via laparoscopy.[8] Moreover, six case series have been reported that describe the efficacy of accessory splenectomy in 38 adults and 12 children for recurrent ITP and are summarized in Table 1.[123591011] Based on these retrospective series, the laparoscopic splenectomy appears to be safe and effective in selected patients although this procedure has been reported to be associated with a higher probability of missing splenuculi; therefore, laparotomy is recommended instead of laparoscopy.[5]

Table 1

Efficacy of accessory splenectomy in adults and children with chronic immune thrombocytopenia

While it is difficult to draw any firm conclusion based on a single case, we propose that laparoscopy is a very useful and reliable tool for the identification of accessory spleens which could not be identified with common imaging modalities. It also permits the effective and safe removal of all accessory splenic tissues in patients with chronic ITP, who relapse with symptomatic thrombocytopenia after primary splenectomy. A detailed preoperative counseling on chances of recurrence is of vital importance and most of these recurrences will need to be tackled surgically either with laparoscopy or laparotomy.

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Conflicts of interest

There are no conflicts of interest.