Trans-sacral (Kraske) approach for gastrointestinal stromal tumour of the lower rectum: old procedure for a new disease

Gastrointestinal stromal tumours (GISTs) of the lower rectum are rare cancers from mesenchymatous origin, which are characterized by; 1) the absence of metastases in loco-regional lymph nodes; and 2) a tendency to grow opposite to the intestinal lumen. Thus, the two preferred surgical approaches for rectal adenocarcinomas (i.e. abdominal and transanal) are inappropriate for GISTs, due to: 1) the uselessness of total mesorectal excision; and 2) to the difficulty to locate the tumour with a transanal approach. We report here a case of a large GIST of the lower rectum which was successfully treated with a posterior trans-sacral approach. Lower rectum GISTs are good indications for the Kraske procedure, and this relatively new disease entity may contribute to the reintroduction of an old procedure into the armamentarium of 21(st) century colorectal surgeons.

[Gastrointestinal stromal tumors (GIST)]

Gastrointestinal stromal tumors (GIST) are the most common digestive mesenchymal tumors. GIST characterized by over-expression of the tyrosine kinase receptor KIT. GIST span a wide clinical spectrum from benign to highly malignant. Surgery is the only curative treatment for GIST. Low malignant GIST have an excellent prognosis after surgical treatment (5 years survival rate > 90%). Highly malignant GIST have an extremely poor prognosis even after surgical resection (median survival < 12 months). The development of tyrosine kinase inhibitors has changed the management of unresectable GIST. One of them, imatinib mesylate, has been proved to improve survival of metastatic GIST. This paper reviews literature data on GIST.

[Scarless surgery: myth or reality through NOTES?]

Natural orifice translumenal endoscopic surgery (NOTES) is an exciting concept bringing scarless surgery a reality consisting in body cavity and organs approach through natural orifices (digestive, female genital, urinary tracts). While new instrumentation necessitated by NOTES is still developing, multiple surgical procedures have been performed with success in human. Whenever this approach combining surgical and endoscopic expertise needs technical improvement and clinical validation, it will have a large impact on the future of surgery related to population demand for scarless surgery. The next decade, will show us if surgery will be performed through NOTES or if minimally invasive surgery will be positively influenced by the technical progress of NOTES to be the most minimally traumatic.

[Vacuum-assisted abdominal closure: its role in the treatment of complex abdominal and perineal wounds. Experience in 48 patients]

INTRODUCTION

Vacuum-assisted closure (VAC) is a promising approach for the management of complex abdominal and perineal wounds. This paper summarizes our experience with this therapeutic modality and demonstrates its efficacity in difficult situations.

PATIENTS AND METHODS

From January 2003 until December 2005, 48 patients (age 30-89) were treated with VAC therapy for open abdomen, infected laparotomy wounds, or tissue loss due to debridement of Fournier's gangrene. Wound dressings were changed every 2-3 days.

RESULTS

Thirty-eight patients (79%) had major co-morbid conditions liable to impact negatively on wound healing. The treatment duration with VAC varied from 20-30 days with an average of eleven dressing changes (minimum 3-maximum 18). Treatment was effective in all patients. Spontaneous closure was achieved in 36 cases (75%); nine patients (19%) required a split-thickness skin graft, and three (6%) underwent delayed secondary closure.

CONCLUSION

In our institution, VAC has become the treatment of choice for complex abdominal and perineal wounds. It is a safe, simple, and effective technique to speed wound healing and it has reduced the duration of hospital treatment in difficult clinical situations and in patients whose general condition is often severely compromised.

Modeling sequencing errors by combining Hidden Markov models

Among the largest resources for biological sequence data is the large amount of expressed sequence tags (ESTs) available in public and proprietary databases. ESTs provide information on transcripts but for technical reasons they often contain sequencing errors. Therefore, when analyzing EST sequences computationally, such errors must be taken into account. Earlier attempts to model error prone coding regions have shown good performance in detecting and predicting these while correcting sequencing errors using codon usage frequencies. In the research presented here, we improve the detection of translation start and stop sites by integrating a more complex mRNA model with codon usage bias based error correction into one hidden Markov model (HMM), thus generalizing this error correction approach to more complex HMMs. We show that our method maintains the performance in detecting coding sequences.

Splicy: a web-based tool for the prediction of possible alternative splicing events from Affymetrix probeset data

Background

The Affymetrix™ technology is nowadays a well-established method for the analysis of gene expression profiles in cancer research studies. However, changes in gene expression levels are not the only way to link genes and disease. The existence of gene isoforms specifically linked with cancer or apoptosis is increasingly found in literature. Hence it is of great interest to associate the results of a gene expression study with updated evidences on the transcript structure and its possible variants.

Results

We present here a web-based software tool, Splicy, whose primary task is to retrieve data on the mapping of Affymetrix™ probes to single exons of gene transcripts and displaying graphically this information projected on the gene physical structure.

Starting from a list of Affymetrix™ probesets the program produces a series of graphical displays, each relative to a transcript associated with the gene targeted by a given probe. The information on the transcript-by-transcript and exon-by-exon mapping of probe pairs can be retrieved both graphically and in the form of tab-separated files. The mapping of single probes to NCBI RefSeq or EMBL cDNAs is handled by the ISREC mapping tables used in the CleanEx Expression Reference Database Project. We currently maintain these mappings for most popular human and mouse Affymetrix™ chips, and Splicy can be queried for matches with human and mouse NCBI RefSeq or EMBL cDNAs.

Conclusion

Splicy generates probeset annotations and images describing the relation between the single probes and intron/exon structure of the target transcript in all its known variants. We think that Splicy will be useful for giving to the researcher a clearer picture of the possible transcript variants linked with a given gene and an additional view on the interpretation of microarray experiment data. Splicy is publicly available and has been realized in the framework of a bioinformatics grant from the Italian Cancer Research Association.

Results from percutaneous drainage of Hinchey stage II diverticulitis guided by computed tomography scan

BACKGROUND

Percutaneous abscess drainage guided by computed tomography scan is considered the initial step in the management of patients presenting with Hinchey II diverticulitis. The rationale behind this approach is to manage the septic complication conservatively and to follow this later using elective sigmoidectomy with primary anastomosis.

METHODS

The clinical outcomes for Hinchey II patients who underwent percutaneous abscess drainage in our institution were reviewed. Drainage was considered a failure when signs of continuing sepsis developed, abscess or fistula recurred within 4 weeks of drainage, and emergency surgical resection with or without a colostomy had to be performed.

RESULTS

A total of 34 patients (17 men and 17 women; median age, 71 years; range, 34-90 years) were considered for analysis. The median abscess size was 6 cm (range, 3-18 cm), and the median duration of drainage was 8 days (range, 1-18 days). Drainage was considered successful for 23 patients (67%). The causes of failure for the remaining 11 patients included continuing sepsis (n = 5), abscess recurrence (n = 5), and fistula formation (n = 1). Ten patients who failed percutaneous abscess drainage underwent an emergency Hartmann procedure, with a median delay of 14 days (range, 1-65 days) between drainage and surgery. Three patients in this group (33%) died in the immediate postoperative period. Among the 23 patients successfully drained, 12 underwent elective sigmoid resection with a primary anastomosis. The median delay between drainage and surgery was 101 days (range, 40-420 days). In this group, there were no anastomotic leaks and no mortality.

CONCLUSION

Drainage of Hinchey II diverticulitis guided by computed scan was successful in two-thirds of the cases, and 35% of the patients eventually underwent a safe elective sigmoid resection with primary anastomosis. By contrast, failure of percutaneous abscess drainage to control sepsis is associated with a high mortality rate when an emergency resection is performed. The current results demonstrate that percutaneous abscess drainage is an effective initial therapeutic approach for patients with Hinchey II diverticulitis, and that emergency surgery should be avoided whenever possible.

Laparoscopic versus open resection for appendix carcinoid

BACKGROUND

Since an increasing number of appendectomies are performed via laparoscopy, it is crucial to determine the impact of this approach on appendix carcinoid (AC) outcome. The goal of this study was to compare results of laparoscopic (LAP) versus open (OP) appendectomy for AC according to intend to treat approach.

METHODS

A retrospective review (1991-2003) identified 39 patients (median age, 36 years; range, 12-83) treated by laparoscopy (LAP) or laparotomy (OP) for AC in a single institution. Follow-up was complete for all patients (median, 67 months; range, 4-132).

RESULTS

Most cases had associated acute appendicitis (64%). Median carcinoid size was 1.1 cm (range, 0.3-5) and 0.4 cm (range, 0.2-3) in the LAP and OP groups, respectively. LAP and OP were performed in 21 (54%) and 18 (46%) patients, respectively. Surgical margins were positive in two patients in the LAP group and one patient in the OP group (p = 0.6). Right colectomies were performed for AC >2 cm in five patients after LAP and in four patients after OP (p = 0.9). Actuarial 5-year survival rates were 100 and 94% in the LAP and OP groups, respectively (p = 0.2). Two patients died in the OP group, one due to metastatic carcinoid and the other due to metachronous colorectal cancer. Synchronous or metachronous colorectal carcinomas developed in six patients (15%).

CONCLUSION

Laparoscopic appendectomy is a safe procedure for AC, with carcinologic and long-term results similar to those of conventional appendectomy. Thus, pre- or per-operative suspicion of AC is not a contraindication to LAP. Prognosis of AC appears more dependent on carcinoid malignant potential or associated tumors. Risk for developing colorectal adenocarcinoma is high in AC patients and warrants follow-up of all patients with colonoscopic screening.

An audit of surgical management of gastrointestinal stromal tumours (GIST)

AIM

To analyze GIST outcome after primary resection and to determine if a new grading system could adequately predict there prognosis.

METHODS

A retrospective review (1993-2002) identified 80 patients who underwent primary surgical resection for, c-KIT positive, GIST. Follow-up was complete for all patients (median follow-up 42, range 1-132, months). GIST were classified as low or high grade according to the following parameters: size, mitotic rate, mitotic index (MiB1), presence of necrosis, invasion of adjacent structure and presence of metastasis.

RESULTS

GIST originated from the stomach (46), small bowel (30), colon and rectum two and mesentery two. At surgery, 94% of cases presented with localized disease and 6% blood born metastasis with or without lymph node invasion. Resections were complete (R0) in 72 cases. R0 resection correlated with prognosis (p<0.01). Sixty GIST were classified as low grade (median follow-up 60 months) and 20 as high grade (median follow-up 27 months). Five-year actuarial survival of patients with low or high grade GIST were of 95 and 21%, respectively, (p<0.001).

CONCLUSION

Prognosis of GIST after surgical treatment is influenced by completeness of primary resection and tumour malignant potential. Low grade GIST have an excellent prognosis after surgery alone, while high grade GIST have a high rate of recurrence after primary resection. Adjuvant treatment should be advocated for patient with either high grade GIST or after incomplete primary resection. The presented grading system can reliably predict GIST outcome after primary surgical treatment. Complete surgical resection offers good chance of cure for low grade GIST, while for high grade GIST surgery alone is not sufficient. The presented grading system could be used to identify patients who may benefit of adjuvant treatment with imatinib mesylate after GIST resection.

[Diabetes Type I therapy through transplantation]

Diabetes is one of the most common chronic diseases in our society. While insulin treatment for diabetes type I could delay and reduce the incidence of diabetic complications, it is associated with an increased risk of severe hypoglycemia. To restore physiologic insulin metabolism, transplantation of insulin producing cells (pancreatic Beta cells) represent the sole available therapy. It could be done either through pancreas or islet of Langerhans transplantation. In this paper, we review actual knowledge regarding these two types of transplantations.

Randomized clinical trial of mechanical bowel preparation versus no preparation before elective left-sided colorectal surgery

BACKGROUND

Mechanical bowel preparation (MBP) is performed routinely before colorectal surgery to reduce the risk of postoperative infectious complications. The aim of this randomized clinical trial was to compare the outcome of patients who underwent elective left-sided colorectal surgery with or without MBP.

METHODS

Patients scheduled for elective left-sided colorectal resection with primary anastomosis were randomized to preoperative MBP (3 litres of polyethylene glycol) (group 1) or surgery without MBP (group 2). Postoperative abdominal infectious complications and extra-abdominal morbidity were recorded prospectively.

RESULTS

One hundred and fifty-three patients were included in the study, 78 in group 1 and 75 in group 2. Demographic, clinical and treatment characteristics did not differ significantly between the two groups. The overall rate of abdominal infectious complications (anastomotic leak, intra-abdominal abscess, peritonitis and wound infection) was 22 per cent in group 1 and 8 per cent in group 2 (P = 0.028). Anastomotic leak occurred in five patients (6 per cent) in group 1 and one (1 per cent) in group 2 (P = 0.210) [corrected] Extra-abdominal morbidity rates were 24 and 11 per cent respectively (P = 0.034). Hospital stay was longer for patients who had MBP (mean(s.d.) 14.9(13.1) versus 9.9(3.8) days; P = 0.024).

CONCLUSION

Elective left-sided colorectal surgery without MBP is safe and is associated with reduced postoperative morbidity.

Serva collagenase NB1: a new enzyme preparation for human islet isolation

INTRODUCTION

Advances in the rate of success of human islet isolation are due in part to the availability of new purified enzyme blends. In this study we evaluated a new enzyme preparation composed of a highly purified collagenase that can be reproducibly blended with predetermined amounts of separately packaged neutral protease.

METHODS

Nine human islet isolations were performed with collagenase NB1 supplemented with neutral protease (Serva Electrophoresis GMbH, group I). Yields, purity, morphology, in vitro function and islet cell apoptosis were assessed. The results were compared to those of nine human islet isolations performed with Liberase (Roche, group II) and matched for donor age, BMI, and circumstances of death.

RESULTS

Islet yields were similar in both groups. However, islet equivalents (IE) per gram of pancreas and IE number to islet number were higher in group I (P <.05). Stimulation indices after insulin response to glucose (static incubation) were similar in both groups. Islet cell apoptosis rate was statistically significantly lower in group I. Islet morphology was significantly improved in group I with a higher proportion of intact islets.

CONCLUSION

This new enzyme preparation (collagenase NB1 with neutral protease adjunct) was as effective as Liberase in terms of islet yields and function. Islet morphology was improved and rate of islet cell apoptosis was lower with this new collagenase. The absence of lot-to-lot variability in terms of neutral protease to collagenase ratio makes collagenase NB1 a promising enzyme for human islet isolation.

Short-term immunosuppression reduces fibrotic cellular infiltration around barium-M-alginate microbeads injected intraportally

INTRODUCTION

One of the major barriers affecting the viability of encapsulated islets is pericapsular fibrotic infiltration (PFI). This study aimed to design strategies to reduce PFI around intraportally injected alginate microbeads.

METHODS

Empty, highly purified, barium-M-alginate microbeads (400 microm) were injected intraportally into Lewis rats (3000 beads/rat). Rats (n = 9/group) were treated daily with either rapamycine (RAPA; 1 mg/kg/d p.o.), tacrolimus (TAC; 2 mg/kg/d p.o.), a combination of both, or gadolinium-chloride (GdC13, 20 mg/kg/d i.v., at day -1 and day +4). Treatment was discontinued at 10 days. Three rats/group were sacrificed at 3, 7, and 42 days after transplantation. Cellular composition of PFI was evaluated by immunohistochemistry. Severity of the reaction to the beads was determined by measuring the thickness of PFI on histology.

RESULTS

The main cellular components of PFI in the liver were macrophages and myofibroblasts. There was a significant (P <.05) reduction in the thickness of PFI in all treated groups, even 6 weeks after transplantation. Encapsulated rat islets showed excellent insulin response to glucose in vitro, with a stimulation index of 3.6 +/- 2.0.

CONCLUSION

Combination of highly purified alginate with short-term immunosuppression reduces fibrotic overgrowth around microbeads injected intraportally.

Morbidity associated with intraportal islet transplantation

INTRODUCTION

Complications associated with intraportal islet infusion have been reported. In this study, we analyzed the relationship between occurrence of complications and islet preparation characteristics/infusion technique.

METHODS

We reviewed all intraportal islet infusions from 1992 to 2003.

RESULTS

Sixteen islet autotransplantations were performed without infusion-related complications. The tissue volume injected was 13 +/- 11 mL with basal and peak portal pressures of 13 +/- 6 and 21 +/- 6 mm Hg. Seventy-seven intraportal islet allotransplantations were performed in 51 patients. Fifteen islet infusions were done by laparotomy during simultaneous islet/kidney transplantation without complication. Among 62 percutaneous transhepatic injections, nine complications (two portal branch thrombosis and seven intra-abdominal hemorrhages) were recorded. Rise in portal pressure was related to tissue volume injected (P <.05). Basal and peak portal pressures were 14 +/- 5 and 18 +/- 6 mm Hg in uncomplicated infusions, 14 +/- 9 and 18 +/- 9 mm Hg in the thrombosis group, and 13 +/- 7 and 18 +/- 5 mm Hg in the hemorrhage group (P >.05). Complications occurred only after percutaneous islet infusion (P <.03).

CONCLUSIONS

Procedure-related morbidity of intraportal islet infusion is low. Changes in portal pressure are related to volume of tissue injected but do not seem to be associated with the occurrence of complications. Percutaneous infusion is a minimally invasive procedure, but this advantage must be balanced by the higher rate of complications.

Microbial surveillance during human pancreatic islet isolation

OBJECTIVES

The study aim was to investigate the microbiological safety of islet isolation and transplantation.

MATERIALS AND METHODS

Between 1996 and 2002, prospective microbiological screening was performed on all pancreata procured for islet transplantation. Pancreas transport media and postpurification preparations were screened for microbiological contamination. Prior to isolation, pancreata were washed with either Hanks solution (group I, n = 170) or decontaminated with antiseptic and antimicrobial drugs (group II, n = 45).

RESULTS

Microbiological contamination of the pancreas preservation media was shown in 62%. Analysis of the contaminants showed 74% gram-positive, 21% gram-negative organisms, and 5% fungi. The donor condition or procurement center did not influence the contamination rate. Longer pancreas transport duration was significantly associated with bacterial contamination (P <.05). In group I, 16 (9.4%) of 170 islet preparations presented microbial contamination at the end of the isolation procedures. Gram-positive organisms were present in 10 (6%), gram-negative organisms in 4 (2.4%), and fungi in 2 (1.2%) preparations. Four islet preparations (2.4%) from pancreata with noninfected transport medium were positive on postpurification cultures, all with gram-positive organisms. In group II, only 2 of 45 islet preparations (4.4%) presented microbial contamination at the end of the isolation process.

CONCLUSIONS

The rate of microbial contamination during pancreas procurement and transport is high. Significant contaminants present when beginning islet isolation become undetectable by the conclusion of isolation. Diminishing the bio-burden by pancreas decontamination reduces the risk of contamination of the final islet preparation.

Optimization of neutral protease to collagenase activity ratio for islet of Langerhans isolation

AIM

The optimal neutral protease to collagenase activity ratio has not been determined for islet isolation. We evaluated a new highly purified collagenase that can be blended with predetermined amounts of neutral protease (NP).

METHODS

Islets were isolated from 7 groups of Sprague-Dawley rats. In group I, collagenase type XI (Sigma) at 2 mg/mL, and, in group II, Liberase at 0.6 mg/mL (2.4 PZ- U/mL; Roche) were used as controls. In groups III to VII, collagenase NB1 0.6 mg/mL (2.4 PZ-U/mL; Serva Electrophoresis) was used with increasing amounts of added NP. The NP to collagenase activity ratio (DMC-U/PZ-U) increased from 0.5% in group III to 2.0% in group VII.

RESULTS

Mean islet equivalent (IE) yields per rat were 1367, 1755, 597, 895, 1712, 1043, and 905 in groups I to VII. IE yields were maximal at DMC-U/PZ-U = 1.2%. Islet morphology was influenced by NP concentration with decreasing numbers of trapped islets and increasing numbers of fragmented islets as NP contents increased. Cytokine release, islet cell apoptosis, and in vitro function were significantly better in groups III to VII as compared with groups I and II.

CONCLUSION

NP is a crucial additive to collagenase for islet isolation. Optimization of the NP to collagenase activity ratio (1.2% in this model) improves yields and morphology after islet isolation.

Impact of a Sirolimus/Tacrolimus-Based Immunosuppressive Regimen on Kidney Function After Islet Transplantation

AIM

Islet transplantation is gaining recognition as a therapeutic option for selected diabetic patients. The immunosuppressive regimen based on sirolimus/low-dose tacrolimus is considered a major breakthrough that allowed considerable improvement in graft survival. A high incidence of side effects associated with such a regimen has been reported in the literature, but this immunosuppressive protocol is generally considered safe or even protective to the kidney. Herein, we analyze the impact of the sirolimus/low-dose tacrolimus-based protocol on kidney function.

PATIENTS AND METHODS

Five islet-after-kidney and 5 islet-transplant-alone patients were enrolled and followed up. Renal function was assessed by the periodic measurement of serum creatinine and by the presence of albuminuria. Metabolic control markers and graft function were followed, as well as immunosuppressive whole blood trough levels.

RESULTS

Kidney function significantly decreased in 6 of 10 patients. Neither metabolic markers nor immunosuppressive drugs levels were significantly associated with the decreased kidney function.

CONCLUSION

Although a specific etiology was not identified, subsets of patients presented a higher risk for decrease of kidney function. The presence of low creatinine clearance, albuminuria, and long-established kidney graft were associated with poorer outcomes.

Role of CD40-CD154 pathway in the rejection of concordant and discordant xenogeneic islets

BACKGROUND

Costimulatory blockade has been shown to allow long-term survival of xenogeneic islets. The aim of the present study was to evaluate the role of recipient CD40 and CD154 in the rejection process of concordant and discordant islet xenotransplantation (Tx).

METHODS

Diabetic C57BL/6 mice, CD40- or CD154 knockout (KO) mice were transplanted with either concordant rat or discordant human islets.

EXPERIMENTAL DESIGN

group 1, control (ie, C57BL/6 mice received islet Tx without therapy); group 2, C57BL/6 mice received islet Tx with anti-CD154 monoclonal Ab (mAb) therapy; group 3, CD40 KO mice; and group 4, CD154 KO mice were used as recipients without therapy. Mouse anti-rat mixed lymphocyte reactions (MLR) were performed using mouse splenocytes obtained from animals transplanted with rat islets in groups 1 to 4.

RESULTS

In group 2, short-term anti-CD154 mAb therapy significantly prolonged rat-to-mouse and human-to-mouse xenograft survival, compared to controls. In CD40-KO and CD154-KO recipients, survival of concordant or discordant islets was not prolonged significantly compared to control groups. Mouse anti-donor rat cellular responses were reduced approximately 50% in group 2 but remained unmodified in groups 3 and 4, when compared to group 1.

CONCLUSIONS

Improved graft survival and reduced MLR responses against donor cells in vitro among the anti-CD154 mAb-treated mice could be explained by specific targeting of activated T cells with subsequent inactivation by anergy and/or elimination by apoptosis, or complement- or cellular-mediated mechanisms. Rejection of xenografts and strong MLR responses against donor cells in vitro in CD40 or CD154 KO animals is possible through efficient activation of alternate pathways of costimulation.

Phylogenetic disparity influences the predominance of direct over indirect pathway of antigen presentation in islet xenotransplantation

BACKGROUND

Cellular immunity plays a major role in rejection of xenografted islets. Depending on the phylogenetical disparity, direct or indirect antigen presentation is predominant. The aim of this study was to analyze in vitro the predominance of direct or indirect presentation, and in vivo the effect of macrophage depletion on concordant and discordant islet xenograft survival.

MATERIALS AND METHODS

In vitro, we performed mouse antirat and mouse antihuman mixed lymphocyte reactions (MLR) after depletion of responder or stimulator antigen-presenting cells. In vivo, streptozotocin-induced diabetic C57BL/6 mice were treated by gadolinium chloride to deplete macrophages and rat or human islets were transplanted under the kidney capsule. Islet function was followed by glycemia and xenografts were analyzed at regular intervals for histology.

RESULTS

Mouse antirat MLR showed a predominant direct antigen presentation pathway, whereas in mouse antihuman MLR, direct and indirect pathways were similarly involved. Survival of rat islets was not modified by GdCl therapy. In contrast, survival of human islets was significantly prolonged in GdCl-treated mice. Macrophage infiltration was decreased in concordant and discordant GdCl-treated xenografts at day 4, compared to controls. At day 15, macrophage infiltration was similar in all groups.

DISCUSSION

Our results indicate that direct antigen presentation is dominant in rejection of concordant islet xenografts and cannot be influenced by host macrophage depletion. Both direct and indirect antigen presentation are involved in rejection of discordant xenogeneic islets. Macrophage depletion or inhibition should be considered as therapeutic tool for discordant islet xenotransplantation.

Successful islet after kidney transplantations in a distance over 1000 kilometres: Preliminary results of the Budapest-Geneva collaboration

To overcome critical islet processing and to ensure patient safety and quality care, we have established an international collaboration between two geographically distant transplant centers for islet transplantation. Four pancreata were harvested and immediately preserved by the two-layer method (oxygenated perfluorocarbon+University of Wisconsin) and subsequently transported for the automated method isolation to Geneva. After purification, the islets were cultured overnight and transported the next day back to Budapest. Three consecutive kidney transplant patients with type 1 diabetes mellitus underwent islet transplantation via percutaneous transhepatic portal embolization using the bag-method. The immunosuppression consisted of daclizumab, sirolimus, and low-dose tacrolimus. Mean donor age was 43.7 years, mean body mass index: 26.5. The islet isolation process began within 8 hours from the donor aorta cross-clamp in all cases. The isolation success rate was 80% (4 of 5). In Budapest, the islets were assessed for viability. No complications occurred during the transplantation, and the portal pressure remained within the normal range. The first patient received 12,000 IU/BW from two donors and the insulin requirement decreased from 40 U/d to 10 U/d. The second patient received 7200 IU/BW from a single donor and became immediately insulin free. The third patient was given 7100 IU/BW; the insulin requirement decreased from 39 U/d to 14 U/d. Posttransplant follow-up for the three patients are 7 months, 4 months, and 2 weeks, respectively. All patients achieved metabolic stability. These preliminary results demonstrate the feasibility of an international collaborative islet transplantation program at a distance over 1000 km.

Retransplantation of discordant xenogeneic islets with costimulatory blockade

BACKGROUND

The aim of the study was to analyze the possibility of xenogeneic islet retransplantation using costimulatory blockade.

METHODS

Streptozotocin-induced diabetic mice were transplanted under the kidney capsule with human islets. Mice were nephrectomized and retransplanted with 1000 human islets under the contralateral kidney capsule 14 days later. Four groups were performed group I, first and second Tx without MR1; group II, first Tx without MR1, second Tx with MR1; group III, first Tx with MR1, second Tx without MR1; group IV, first and second Tx with MR1. A control group was transplanted only once without MR1 with human islets. After second Tx, cross-matches between recipient, serum and human lymphocyte were done for detection of antidonor antibodies.

RESULTS

In the control group, mean graft survival was 13 (+/-7) days. In group I, mean graft survival was 5 +/- 3 days. In group II, mean graft survival was 16 +/- 13 days. In group III, mean graft survival was 81 +/- 22 days. In group IV, no rejection were recorded and all graft survived more than 120 days. Pretransplant cross-matches were negative. In groups I and II all cross-matches were positive, while none were positive in group IV.

CONCLUSION

Retransplantation of xenogeneic islets was associated with accelerated rejection. After presensitization, MR1 was unable to induce tolerance to a second Tx. MR1 given at the first Tx only allowed prolonged survival of the second Tx, but rejection still occurred. MR1 given at first and second Tx allowed long-term survival of retransplanted xenoislets and prevented occurrence of antidonor antibodies.

Appendix tumors in the era of laparoscopic appendectomy

BACKGROUND

The safety of laparoscopic appendectomy for the management of incidentally discovered appendiceal tumors has not yet been established.

METHODS

Appendiceal tumor cases managed by laparoscopy or laparotomy over a 10-year period were reviewed.

RESULTS

The pathological diagnoses were 23 carcinoid and 20 cancerous lesions. The median patient ages were 36 and 69 years, respectively, for carcinoid and other tumors (p < 0.05). Acute appendicitis was present in 70% of carcinoid cases and 35% of other tumors (p < 0.05). Eight patients with carcinoid tumors were operated on by laparoscopy, whereas 15 underwent laparotomy. Laparoscopic and open procedures were performed in three and 17 patients with cancerous lesions, respectively. Invaded surgical margins were seen after laparoscopy in 20% of patients and open surgery in 6%. Synchronous colon carcinoma was detected in 14% of the patients with an appendix neoplasm. The 5-year survival rates were similar after both laparoscopic and open appendectomy for either carcinoid or other tumors.

CONCLUSION

Laparoscopic appendectomy for appendiceal tumors seems to have a slightly higher rate of inadequate resection. However, it is not associated with a significantly worse patient prognosis than open appendectomy.

Islet of langerhans allogeneic transplantation at the university of geneva in the steroid free era in islet after kidney and simultaneous islet-kidney transplantations

AIMS

We report a single-center experience of islet allogeneic transplantation in islet after kidney (IAK) and simultaneous islet-kidney (SIK) type 1 diabetic recipients using a steroid-free immunosuppressive regimen.

METHODS

Eight patients received 12 islet infusions in 5 IAK and 3 SIK procedures. Median age was 51 years (range, 30-58 years) with a male:female ratio of 2:6. IAK was considered only for patients with a stable kidney function and a creatinine clearance level >60 mL/min. SIK was considered for patients with a counterindication for simultaneous kidney-pancreas transplantation. Immunosuppression was based on sirolimus/tacrolimus combined with daclizumab induction. Two consecutive infusions of >5000 islet equivalents (IEQ)/kg were planned.

RESULTS

Five patients completed the transplantation course, whereas 3 patients received only 1 islet infusion. All patients have functional grafts (C-peptide >166 pmol/L) at 6-month median follow-up. Of 5 patients who completed their transplantation course 4 became insulin independent. HbA1c and fructosamine decreased over time, showing improved metabolic control. Severe adverse events were observed in 4 patients. One SIK patient died after OKT-3 treatment of severe kidney rejection.

CONCLUSIONS

The Edmonton immunosuppressive protocol can be applied for patients undergoing either IAK or SIK procedures, with a high rate of graft function and insulin independence. Morbidity is higher than among patients undergoing solitary islet transplantation for type 1 brittle diabetes.