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Biomedical subjects

M Giessing

Publications and source records attributed to M Giessing.

At least 19 recordsLinked to original sources

[Modern immunosuppression following renal transplantation. Standard or tailor made?].

Renal transplantation is by far the best therapeutic option for end-stage kidney disease with respect to quality of life, psychosocial rehabilitation, and even patient survival. Optimal immunosuppressive therapy should provide effective prophylaxis of both acute rejection and chronic allograft dysfunction. Thus immunosuppressive therapy should help to maintain good renal function and could help to prevent premature death of the recipient. With the introduction of new immunosuppressants over the last decade a dramatic reduction of acute rejection rates from approximately 50% to 15-30% could be achieved. However, the search for novel immunosuppressive drugs continues, drugs which not only lead to effective prevention of acute rejection, but also have an impact on chronic allograft dysfunction and prevent further deterioration of this multifactorial process. Based on a short presentation of the "three signal model" of immunoactivation, the most important mechanisms and characteristics of the presently available immunosuppressants are described. Because the immunosuppressive objectives change over time, a phase-dependent adaptation is necessary. At present, most centers in Germany use an immunosuppressive combination therapy, consisting of a calcineurin inhibitor (CNI; cyclosporine or tacrolimus), a glucocorticoid (prednisolone or methylprednisolone), and mycophenolic acid (MPA), which is eventually combined with an antibody (e.g., IL-2R antibody) for induction. In contrast to the clear situation 10 years ago, highly specialized knowledge is required today with respect to mechanism of action, side effects, and potential interactions. This may enable the physician to adopt patient-oriented optimal immunosuppression. In the near future more individualized treatment options will be employed, which are adapted to the characteristics and side effects of the immunosuppressant, as well as to the characteristics of the donor, the recipient, and the transplanted organ such as immunology and ischemia. Another aspect is the reduction or elimination of some immunosuppressants at the earliest possible time. With new diagnostic and genetic markers the relationship between recipient and transplanted organ will be characterized better in the future and therapy will become more individualized. Altogether, these measures as well as optimized supportive therapy will help to further improve the longevity of the transplanted organ.

Chemotherapy, Adjuvant↗

[Kidney transplantation in childhood and adolescence].

The reasons for end-stage renal disease in pediatric patients differ from adults. The therapy of choice is renal transplantation. A total of 117 children and adolescents were treated with renal transplantation in 2003 in Germany. Immunosuppressive therapy and related comorbidities are the main problems in pediatric patients. The following article provides a summary of transplantation in children, preparation, and follow-up.

Adolescent↗

[A new method for standardized diagnosis following renal transplantation. Ultrasound with contrast enhancement].

Ultrasound (US) imaging is an important diagnostic tool following renal transplantation. Unfortunately, due to the heterogeneity of the recipients and their multimorbidity, imaging procedures in the early phase after kidney transplantation are difficult and of limited use. We performed a study to evaluate the use of a contrast enhancer for US examination as a standardized method in the follow-up of kidney transplant recipients.The study included 40 recipients: 32 were examined on the 5th to 7th day following transplantation and 8 patients at the time when clinically suspicious findings occurred (acute rejection, tumor, acute tubular necrosis). Following the intravenous application of the contrast medium, pictures were taken during the arterial and parenchymatous phase and compared with conventional B-mode and power Doppler pictures of the same visual plane. Three examiners assessed different parameters of the transplant organ (max. vascularized area, suspected hematomas, tumors, rejection, acute tubular necrosis). Findings were confirmed by histological results of a biopsy if rejection, tumor, or acute tubular necrosis were suspected. Application of ultrasound contrast medium significantly increased visualization of the vascularized kidney area. Also, US findings in the follow-up after acute rejection therapy corresponded with the clinical course; 19 hematomas could be detected with contrast medium compared to only 9 without. With contrast medium a perfusion deficit was detectable in three patients compared to one patient with power Doppler US. Also, US contrast medium helped to detect tumor vascularization in two patients in whom conventional sonography suspected no abnormality. Ultrasound contrast medium enhancement is a reproducible, reliable, and easy to apply method which is superior to conventional sonography in the follow-up after kidney transplantation. This method is also helpful to detect and control acute rejections and to better visualize hematomas, deficits of perfusion, and tumors.

Adolescent↗

[Ten years of laparoscopic living kidney donation. From an extravagant to a routine procedure].

Ten years ago the first laparoscopic living donor nephrectomy (LDN) was performed. Today, LDN is a routine operation in many US-American transplantation centers and an increasing number of centers in Europe are practicing LDN. In this article the different aspects of LDN for donor, kidney, recipient and operating surgeon are evaluated. We performed a literature research concerning LDN and the different aspects. Our own experience, as the largest LDN center in Germany, is part of the evaluation. Laparoscopic extraction of a kidney from a living donor is as safe for the donor as the open approach. At the same time, LDN offers multiple advantages like reduced pain and shorter convalescence. For the donated kidney and the recipient no disadvantages occur from the laparoscopic technique, as long as special intra- and perioperative demands are met. For the operating surgeon multiple developments have expanded the technical armentarium. LDN is safe for donor, recipient and kidney. Central issue of an optimal LDN is sufficient experience with laparoscopic urological techniques.

Directed Tissue Donation↗

[Urological evaluation and follow-up of the kidney transplant patient].

Patients with end-stage renal disease awaiting kidney transplantation require regular urological evaluation. The urologist's main task is early diagnosis and treatment of genitourinary malignancies and evaluation of the lower urinary tract. Furthermore, urologists are often confronted with the question of whether or not to perform pretransplant urological surgery, i.e., native nephrectomy for polycystic kidney disease. Urological care after kidney transplantation involves diagnosis and treatment of ureteral complications, malignancies, lower urinary tract symptoms, and last but not least erectile dysfunction, which has a prevalence of 20-50% among kidney transplant recipients. For the evaluation and follow-up of the living kidney donor, international guidelines have been developed in recent years to also help the urologist to perform a correct evaluation and follow-up of the kidney donor.

Germany↗

Laparoscopic versus open donor nephrectomy in Germany: impact on donor health-related quality of life and willingness to donate.

INTRODUCTION: Laparoscopic living donor nephrectomy (LDN) offers multiple advantages to the donor. Since 1999 LDN has become the only surgical approach for living kidney donation in our department. To our knowledge a donor health-related quality of life (QoL) has not yet been performed with standardized and validated questionnaires to compare laparoscopic with open nephrectomy. We therefore performed a study with two questionnaires (SF-36/GBB-24) and one set of open questions for all donors in our department. METHODS: Questionnaires were sent out to all donors between 1983 and 2001 with at least a 1-year follow-up. To exclude a bias a maximum response rate was sought; donors who did not answer were recontacted as well as their recipients or their physicians to motivate them for participation. RESULTS: The response rate was (89.8%). Except for less limb pain in the laparoscopy group, no difference could be detected for donors QoL with respect to the surgical method. Willingness to donate again was not affected by the surgical method. Nevertheless if asked again today, most donors want laparoscopic kidney retrieval. CONCLUSIONS: Donors health-related QoL is not affected by the surgical method when queried retrospectively. Nevertheless, most donors today would favor laparoscopy, if they could chose again. How laparoscopy affects a reluctant donor to step forward must be determined in a prospective study.

Attitude↗

[Relevance of intraoperative frozen section diagnostics in urological surgery].

Intraoperative frozen section diagnosis (FSD) plays an important role in urological surgery. The surgeon obtains information on suspicious tissue and can adapt his strategy for the operation, thus sparing the patient from a second intervention. Most important for a successful FSD is close co-operation between the urologist and an experienced pathologist. A very reliable assessment of urological tissues can be made with the help of FSD. The same applies for the margin status of tumours, which is most important for example in renal tumour enucleation to achieve the same oncological result as with a radical tumour nephrectomy. For the diagnosis of lymph nodes the indication for FSD depends on the urological primary lesion. Especially for prostate cancers some authors rather recommend the evaluation of the nodal status according to nomograms. FSD for "sentinel nodes" is promising but has not yet found its way into routine diagnostics.

Cystectomy↗

Laparoscopic donor nephrectomy.

Laparoscopic live donor nephrectomy (LDN) has removed disincentives of potential donors and may bear the potential to increase kidney donation. Multiple modifications have been made to abbreviate the learning curve while at the same time guarantee the highest possible level of medical quality for donor and recipient. We reviewed the literature for the evolution of the different LDN techniques and their impact on donor, graft and operating surgeon, including the subtleties of different surgical accesses, vessel handling and organ extraction. We performed a literature search (PubMed, DIMDI, medline) to evaluate the development of the LDN techniques from 1995 to 2003. Today more than 200 centres worldwide perform LDN. Hand-assistance has led to a spread of LDN. Studies comparing open and hand-assisted LDN show a reduction of operating and warm ischaemia times for the hand-assisted LDN. Different surgical access sites (trans- or retroperitoneal), different vessel dissection approaches, donor organ delivery techniques, delivery sites and variations of hand-assistance techniques reflect the evolution of LDN. Proper techniques and their combination for the consecutive surgical steps minimize both warm ischaemia time and operating time while offering the donor a safe minimally invasive laparoscopic procedure. LDN has breathed new life into the moribund field of living kidney donation. Within a few years LDN could become the standard approach in living kidney donation. Surgeons working in this field must be trained thoroughly and well acquainted with the subtleties of the different LDN techniques and their respective advantages and disadvantages.

Journal Article↗

[Evaluation and follow-up of living kidney donors].

An increase in waiting time for a cadaveric organs and a better graft-function, graft- and patient-survival with kidneys from a living donors have lead to an increase in living-donor renal transplantation in the therapy of end-stage renal disease. In Germany, with the implementation of a transplantation law in 1997 and due to improved surgical techniques (laparoscopy) the proportion of living renal donors has almost tripled during the last five years. The transplantation law also names the potential donors, including not only genetically related but also emotionally related donors. Inclusion criteria for living donation are age > 18 years, mental ability to give consent and an altruistic motivation (exclusion of financial benefits for the donor). If ABO blood group compatibility between donor and recipient is given and a cross match does not reveal immunologic obstacles a thorough medical and psychological examination must be performed with the potential donor. All risk factors for the donor beyond the actual operation must be excluded. Therefore all organ-systems have to be evaluated and risks for the donor as well as transferable pathologies and infections must be ruled out. International guidelines help to perform an efficient evaluation. Following organ donation the donor should be medically controlled as requested by law. Also, psychological counselling should be offered. The aim is to minimize risks for the single kidney and to recognize early potentially kidney damaging affections.

Contraindications↗

[Kidney donors and kidney transplantation in the elderly].

The likelihood of terminal renal insufficiency escalates with age, increasing the risk of dying as a patient requiring dialysis. In 1999, Eurotransplant initiated the Eurotransplant Senior Programm (ESP), in which the kidneys of old donors (>64 years) are allocated to recipients 64 years and older. Allocation does not take HLA-matching into account and is performed regionally only according to blood-group-compatibility to keep the storage time short. As a consequence of the short ischemic time, and thus reduced non-immunological damage to the anyways susceptible old kidney, graft-function and graft-survival in the ESP are very good. The results of the initial 5 years of this program show that it successfully utilizes more kidneys from old donors and that more old recipients are being transplanted, with a satisfactory graft-function. Increased donor- and/or recipient age require a thorough evaluation to exclude malignant and other diseases. Furthermore, short term controls on the waiting list and following kidney transplantation are prerequisites for successful transplantation in the aged recipient. If this is guaranteed, kidney transplantation in the old recipient-even with old donor organs-is a good alternative to the morbidity of a prolonged dialysis. Nevertheless, the role of HLA-matching should be reconsidered to reduce rejections.

Aged↗

[Laparoscopic living donor nephrectomy of kidneys with multiple renal vessels].

Due to the increasing waiting time for transplantation of a cadaveric kidney, living donor kidney transplantation is an increasingly oncoming issue. Laparoscopic donor nephrectomies (LDN) have been performed since 1995 and presently more than 100 transplant centers offer this minimally invasive surgical approach. The advantages for the donor of less pain, shorter hospital stay, earlier return to work, better cosmetic results in combination with an organ function equal to open donor nephrectomy are the reasons for an enormous increase in LDN. Since up to 30% of the donor kidneys have multiple vessels for blood supply, an increase of these organs for LDN can be expected. We performed a retrospective study of LDN at our center and compared donors with multiple vs single vessel supply. From February 1999 to September 2002, 63 LDN were performed at the department of Urology, Charité University Hospital, Berlin. A comparison between 18 donor kidneys with multiple vessel supply and 45 donor organs with single vessels showed no difference for the time of laparoscopic explantation (207 vs 201 min, p=0.4) or the warm (166 vs 148 s, p=0.2) and cold ischemic times (117 vs 103 min, p=0.66). As could be expected, the mixed ischemic time, i.e., the time for anastomosis of the kidney with the recipient's vessels, showed a significant difference (53 vs 46 min, p=0.02). Intra- and postoperative complication rates for donors and recipients were not different in both groups. Laparoscopic donor nephrectomy for kidneys with multiple vessels is feasible and safe for donor and recipient.

Adult↗

[Laparoscopic transperitoneal donor nephrectomy. Technique and results].

Living donor kidney transplantation is one possibility to meet the growing demand for organs in patients with chronic renal failure. In 1995 the first laparoscopic living donor nephrectomy (LDN) was performed in the United States. More than 100 transplant centers worldwide perform LDN. The expectations of a larger number of willing organ donors were fulfilled due to the less traumatic operation. Meanwhile, several techniques exist to retrieve a kidney laparoscopically, including the trans- or retroperitoneal, strictly laparoscopic, or hand-assisted approach. From February 1999 to September 2002, 63 strictly laparoscopic, transperitoneal LDNs were performed at the Department of Urology of the Charité University Hospital, Berlin. Warm ischemic time was 148 s (105-360) and operating time was 203 min (110-305). Intraoperative complications were due to insufficient closure of the vessels in four patients. Mean postoperative hospital stay was 5.7 days (3-9). One year after LDN, renal function as well as creatinine levels of the recipient showed no difference compared to the organs harvested via the approach at our department prior to implementation of LDN. Strictly laparoscopic transperitoneal donor nephrectomy is a safe method for kidney retrieval and ensures excellent graft function.

Adolescent↗

[Laparoscopic dismembered pyeloplasty with Anderson-Hynes technique].

Because of the minimal invasiveness of the laparoscopic approach, we introduced the laparoscopic dismembered pyeloplasty in our treatment modalities for patients with primary UPJ obstruction. We report on our technique and the results after a median follow-up of more than 2 years. Between August 1997 and September 2002, 52 patients underwent a laparoscopic dismembered pyeloplasty at our institution. All patients had a symptomatic primary PJ obstruction. We prefer the transperitoneal route with laterocolic exposure of the kidney. After preparation and exposure of the ureter and the renal pelvis, we performed in each case the dismembered Anderson-Hynes pyeloplasty with resection of the pelvis and reanastomosis between the ureter and renal pelvis. Intracorporeal suturing and knotting techniques were used exclusively. All procedures could be performed successfully. In no case was conversion to open surgery necessary. The mean operative time was 180 min. Crossing vessels were present in 57% of patients. The mean postoperative hospital stay was 4 days. The first patient had an anastomosis insufficiency, which required laparoscopic repair. The same patient failed in the follow-up. He developed a late recurrence of the stenosis and needed an open repair. In all other patients the obstruction was resolved or significantly improved. The long-term success rate is 98% with a follow-up of 25 months. Our results with laparoscopic dismembered pyeloplasties compare favorably with those achieved by open pyeloplasties with less perioperative morbidity and discomfort. We do believe that laparoscopic dismembered pyeloplasty will be the method of choice in the treatment of UPJ obstruction.

Adolescent↗

20-year experience with elderly donors in living renal transplantation.

PURPOSE: This study evaluates the impact of living renal donors (LD) aged 60 years and older on graft performance and patient survival in an old-for-young constellation. PATIENTS AND METHODS: We analyzed 144 consecutive LDs between January 1983 and December 2002 (19 patients 60+/125 controls). RESULTS: Mean donor age in the 60+ group was 63.7 (+/- 2.6) years and 43.7 (+/- 9.0) years for the <60 group. Mean recipient age was 42.4 (+/- 15.2) years versus 32.6 (+/- 15.3) years HLA-A, -B, and DR-mismatches were 3.16 (+/- 1.3) for the 60+ group and 3.13 (+/- 1.7) for the controls (P = NS). Rejection episodes in the first year following LD did not differ (53% versus 33%, P =.25). Mean serum creatinine for 65+ versus <65 after 1, 3, and 12 months was 1.91 +/- 1.2 versus 1.48 +/- 0.85 mg/dL (P =.16), 1.82 +/- 0.89 versus 1.29 +/- 0.35 mg/dL (P <.05) and 1.80 +/- 0.31 versus 1.37 +/- 0.38 mg/dL (P <.05) and mean creatinine clearance at 12 months 62 versus 82 mL/min (P =.06). Censored 1-, 3-, and 5-year graft survival was 100% versus 95% (P = NS), 100% versus 93% (P = NS) and 100% versus 83% (P = NS) with no significant difference in the log-rank test for Kaplan Meier. CONCLUSION: No impact of donor age was found for graft survival but function of the 65+ kidneys at 3 and 12 months was reduced. Living renal donors 60+ are acceptable for carefully allocated recipients.

Adult↗

Living donor nephrectomy--no impact of genetic relationship.

PURPOSE: A retrospective, single-center analysis was conducted to compare the results of living donor kidney transplantation between living unrelated (LURD) and living related (LRD) donors. PATIENTS AND METHODS: One hundred forty-seven consecutive living renal transplantations were performed at our institution, starting in 1983. Graft and patient survival were assessed as well as transplant function, including a subgroup analysis for the period of kidney transplantation. RESULTS: Mean follow up for the LRD group was 88.5 months and for the LURD cohort 34.4 months. One- and 3-year graft survival (censored for death with functioning graft) for LRD versus LURD was 97.5% versus 94.4% (P =.4) and 95.3% versus 88.8% (P =.35). Patient survival at 1 and 3 years was 95.1% versus 94.7% (P =.91) and 87.8% versus 90.0% (P =.79). Of the related recipients, 37% experienced at least one episode of rejection in the first year following renal transplantation, compared to 34% in the LURD group (P =.80). Mean serum creatinine for LRD versus LURD after 1, 3, and 12 months () was 1.52 +/- 0.81 versus 1.59 +/- 1.17 mg/dL (P =.98), 1.41 +/- 0.55 versus 1.30 +/- 0.40 mg/dL (P =.51), and 1.44 +/- 0.39 versus 1.40 +/- 0.40 mg/dL (P =.75). Mean creatinine clearance after 1 year was 82.2 versus 71.7 mL/min (P =.26). Subgroup analysis for the time between 1996 and 2002 revealed no difference between LURD and LRD. Multivariate analysis could exclude an impact of the significantly different recipient age and of first/second warm ischemic time on the endpoints described above. CONCLUSION: LURD is a good way to meet the growing organ shortage and should be encouraged.

Creatinine↗