Experiences of Participation in a Study Investigating Feasibility of the Implantable Doppler Probe in Kidney Transplantation: An Embedded Qualitative Study.

OBJECTIVES: Kidney transplant survival can be improved with better graft surveillance postoperatively. In the quest to explore new technologies, we explored the feasibility of an implantable Doppler probe as a blood flow monitoring device in kidney transplant patients. This qualitative study was embeddedin a feasibility trial and aimed to test the device's clinical acceptability and obtain suggestions for the development of the intervention. Objectives included exploring the experiences of feasibility study participants and identifying barriers to the implementation of implantable Doppler probes in clinical practice. MATERIALS AND METHODS: We conducted semi-structured interviews containing open-ended questions with 12 feasibility study participants recruited by purposive sampling. All interviews were audio-recorded with verbatim transcription. Thematic data analysis was performed at the latent level by using an inductive approach with a previously published 6-phase guide. RESULTS: Three key themes emerged: (1) perceived value of the intervention in clinical practice, (2) challenges and barriers to implementation of the intervention, and (3) suggestions forthe development of the intervention. Due to functional limitations and lack of research, medical professional participants revealed clinical equipoise regarding the utility of implantable Doppler probes. However,the device was well received by patient participants. Challenges included device training needs for medical professionals and educational sessions for patients. Innovative ideas for development included the insertion of a display screen, adopting disposable units to reduce overall cost, online access allowing remote monitoring, decreasing external monitoring unit size, and integrating a wireless connection with the probe to reduce signal errors and increase patient safety. CONCLUSIONS: The clinical need for blood flow sensing technology in kidney transplants has been widely acknowledged. Implantable Doppler probes may be a beneficial adjunct in the early postoperative surveillance of kidney transplant patients. However, the device's technical limitations are the main challenges to its acceptance in clinical practice.

Exploring the Role of an Implantable Doppler Probe as a Blood Flow-Monitoring Device in Kidney Transplant: A Feasibility Randomized Controlled Trial.

OBJECTIVES: Vascular thrombosis is a disastrous postoperative complication resulting in the loss of 3.5% to 5.7% of all kidney transplants. The use of blood flow-sensing technology in the early postoperative period may help in the early identification of vascular complications crucial to reducing graft loss. This study aimed to assess the feasibility of an implantable Doppler probe as a blood flow-monitoring device in kidney transplant recipients and to evaluate its usefulness in the prevention of early graft loss. MATERIALS AND METHODS: This 2-arm feasibility randomized controlled trial compared the demographic characteristics and surgical outcomes of kidney transplant recipients who received implantable Doppler probe monitoring (intervention group; n = 30) with those who had standard clinical care (control group; n = 30). Surgical outcomes compared between the groups included the number of early vascular complications identified,the number of departmental ultrasonography scans requested in the first 72 hours postoperatively, and month 3 graft loss. RESULTS: Both groups were similar in demographic characteristics. In the intervention group versus the control group, fewer ultrasonography scans were requested in the first 24 hours postoperatively (56% vs 91%) and lower graft loss (0% vs 6.6%) was recorded. The results addressed uncertainties around the feasibility study's research methods and required resources for a future pragmatic trial. CONCLUSIONS: An implantable Doppler probe may be a beneficial adjunct for graft monitoring after kidney transplants. This feasibility study provided the necessary preliminary information and filled initial gaps in the evidence that can inform future research. The prespecified progression criteria ofthe study were fulfilled. The study template used can be transferable to other transplant centers across theUnited Kingdom. A pragmatic large-scale randomized controlled trial is warranted to evaluate the effectiveness of implantable Doppler probes in clinical practice.

A Study Protocol Exploring the Role of an Implantable Doppler Probe in Kidney Transplantation: A Feasibility Randomized Controlled Trial with an Embedded Qualitative Study.

OBJECTIVES: Vascular complications in kidney transplant surgery constitute one-third of early graft loss, which can be prevented by timely diagnosis of vascular compromise. A blood flow monitoring device may have a beneficial role in the early identification of graft hypoperfusion critical to reducing graft loss. This research protocol aims to evaluate the potential of an implantable Doppler probe as a blood flow monitoring device in kidney transplant recipients. MATERIALS AND METHODS: The potential study will be a mixed methodology, 2-arm feasibility randomized controlled trial with an embedded qualitative study. For the trial, we will compare demographic characteristics and outcome measures of kidney transplant patients receiving implantable Doppler probe monitoring (intervention group, n = 30) with those having standard clinical care (control group). For the qualitative study, we will conduct semi-structured interviews with stakeholders (n = 12) recruited by purposive sampling to explore experiences of participants. All interviews will be audio recorded with verbatim transcription. RESULTS: Our results will use the summarized quantitative data and descriptive statistics to determine differences between the groups. We will use CONSORT guidelines to determine the suitability of the research processes, availability of research resources, and potential challenges faced during the feasibility randomized controlled trial. We will use thematic analysis and NVivo software to analyze the acceptability of the intervention in clinical practice. We will compile the results according to the consolidated criteria for reporting qualitative research checklist. CONCLUSIONS: The goal of this protocol is to determine the feasibility of an implantable Doppler probe monitoring device in kidney transplant recipients. The feasibility study will collect preliminary information, fill gaps in evidence, and test research processes for the pragmatic future randomized controlled trial. The template of this study is transferable to other transplant centers across the United Kingdom.

Iliofemoral Polytetrafluoroethylene Graft Interposition: A Rescue Procedure in External Iliac Artery Dissection to Restore Lower Limb Revascularization and Salvage Kidney Transplant.

External iliac artery dissection is a catastrophic complication during kidney transplant surgery. We present a technically challenging case of external iliac artery dissection that occurred in severely atherosclerotic vessels of a high-risk patient receiving his third kidney transplant. The intimal dissection constituted by the upstream application of a vascular clamp during the preparatory dissection ofthe vessels and progressed rapidly along the iliofemoral axis. The external iliac artery was severely diseased and in an irreparable condition, hence ligated and removed. After a common iliac endarterectomy, an iliofemoral polytetrafluoroethylene vascular graft interposition was performed. The transplant kidney was anastomosed directly on the vascular graft. Satisfactory lower limb vascularization and kidney transplant perfusion were achieved withouttechnical difficulties. The patient had an uneventful recovery without complications. The kidney transplant recipient retained stable graft function at 6 months postoperatively. This rare case highlights the benefit of a surgical strategy in a vascular emergency that threatens the lower limb during a kidney transplant, and we emphasize the technical details of the procedure. As patients with extended indications are accepted onto the transplant waiting list, it is important for transplant surgeons to acquire surgical skills of vascular graft interposition. A postoperative blood flow monitoring device may be beneficial in high-risk kidney transplant cases.

Exploring Views and Expectations of Clinicians, Nurses, and Kidney Transplant Recipients Regarding Protocol Development of a Study to Investigate Feasibility of the Implantable Doppler Probe in Kidney Transplantation: Patient-Public Involvement Consultations.

OBJECTIVES: The shortage of donor organs is the most limiting factor in kidney transplant practice today. New monitoring technologies are being investigated to reduce graft loss due to vascular complications. We assessed the feasibility of a novel blood flow monitoring device, the implantable Doppler probe, in kidney transplant surgery. This patient-public involvement consultation explored the views and expectations of the stakeholders (kidney transplant recipients, surgeons, clinicians, and nurses with direct experience of the implantable Doppler probe) on the protocol development of our feasibility study. Our objective was to improve the protocol, understand stakeholder perceptions regarding research in postoperative graft surveillance, and identify potential confounding factors to the research and challenges to implementation of implantable Doppler probe in clinical practice. MATERIALS AND METHODS: We conducted semi-structured interviews containing open-ended questions with 12 stakeholders. We performed thematic analysis of the data at the latent level by an inductive approach according to a 6-phase guide by Braun and Clarke using NVivo 12 software. RESULTS: Three key themes emerged. (1) Experiences with the implantable Doppler probe as a monitoring device showed that it was well received by the patients; however, there was a clinical equipoise among the health care professionals. (2) Recognition of the need for research in the early postoperative graft monitoring displayed stakeholder understanding regarding the role of a blood flow monitoring device to improve surgical outcomes. (3) Recommendations for smooth conduct of the proposed study include suggestions for improvement of the study protocol, informative sessions for the patients and nurses, and innovative ideas to improve the monitoring device. CONCLUSIONS: Patient-public involvement consultation was crucial for the research design of our proposed feasibility study. Useful strategies and a patient- centered approach were incorporated to mitigate the potential challenges to the conduct of the research.

The Use of the Implantable Doppler Probe as a Blood Flow Monitoring Device in Clinical Settings: A Narrative Review of the Evidence.

OBJECTIVES: In the past decade, the implantable Doppler probe has been studied widely as a blood flow-monitoring device in reconstructive and transplant surgical specialities. Its utility as an effective postoperative monitoring technique is still debatable, with no clear guidelines in clinical practice. Here, we mapped the current evidence on the usefulness of the implantable Doppler probe as a blood flow-monitoring device. The objective was to present an up-to-date assessment of the benefits and limitations of using implantable Doppler probes in clinical and experimental clinical settings. MATERIALS AND METHODS: We conducted a literature search using the Cochrane Library and Healthcare Databases Advanced Search and using implantable Doppler probe, transplant, graft, and flap as key words. The search yielded 184 studies, with 73 studies included after exclusions. We evaluated, synthesized, and summarized the evidence from the studies in tabular form. RESULTS: There is clinical equipoise regarding the effectiveness of implantable Doppler probe as a flow sensing technique. The main reason is the lack of information and gaps in the evidence regarding the benefits and limitations of using implantable Doppler probes in clinical practice. CONCLUSIONS: The implantable Doppler probe has the potentialto be used as an adjunctpostoperativeblood flow-monitoring device. However, keeping in view of technical limitations, its signals should be interpreted alongside traditional clinical assessment techniques to determine the patency of microvascular anastomosis. Although evidence in this review will inform clinical practice in transplant and reconstructive surgical specialties, a prospective randomized controlled study with a larger patient cohort is required to evaluate the effectiveness of this probe in clinical settings.

Survey of Patient's Experience of Altruistic Nondirected Kidney Donation.

The scarcity of organs for donation is an ongoing issue. Change in legislative framework allows for altruistic donations in the UK, but, whereas the number of donations from deceased donors has increased, there has been a slow decline in altruistic living donors. The aim of this study was to review perspectives of altruistic nondirected kidney donors (ANDKD) at our center and outcome of all enquiries to inform service improvement and increase the numbers of donors. All enquiries by potential ANDKD at our center from September 2005 to September 2017 were analyzed. Donor assessment was performed as per the UK Guidelines, prior to obtaining Human Tissue Authority approval. The outcome of donation and results of questionnaires sent to 50 ANDKD were analyzed. During the period, 51 of the 180 enquiries (28.3%) resulted in kidney donation. Questionnaire responses were: 66% donors were retired; most heard about altruistic donation through media (60%); 72% thought psychological or psychiatric assessment was necessary; 95% found the information provided prior to donation adequate; 82% rated their overall experience as good/excellent; and 90% would recommend kidney donation to others. Thirteen of 50 donated kidneys were fed into the kidney exchange program. The mean ± standard error of the mean of the duration from human tissue authority approval to donation were 60.4 ± 5.4 and 131.2 ± 11.2 days, respectively (P = 0.00001). A significant proportion of enquiries for altruistic donation would result in donation but the assessment process needs to be quicker. ANDKD is useful way of priming the National Living Donor Kidney Sharing Scheme.

Living kidney donor assessment: Kidney length vs differential function.

BACKGROUND: The key question in living kidney donor assessment is how best to determine the contribution of each kidney to overall renal function and guide selection of which kidney to donate, ensuring safety of procedure and good outcome for both recipient and donor. It is thought that a length difference > 2 cm may indicate significant difference in function and therefore need for measurement of differential function. AIM: To determine the effect of using kidney length to decide which kidney to donate in a retrospective cohort of potential donors. METHODS: All 333 potential living kidney donors between January 2009 and August 2018 who completed assessment were retrospectively evaluated. Donor assessment was performed as per United Kingdom guidelines. Data included age, sex, kidney length (cranio-caudal) obtained by computed tomography/ultrasono-graphy,51-chromium ethylenediamine tetraacetatic acid measured glomerular filtration rate, mercapto acetyl tri glycine split function and vascular anatomy. There were 48 exclusions due to inadequate data or incomplete investigations. Statistical analysis was performed using Excel pivot tables and GraphPad Prism. Correlation between kidney length and differential function was determined with Pearson's correlation coefficient. RESULTS: Of 285 potential donors included in the study, there were 144 males (mean age 49.9 ± 14.75) and 141 females (mean age 51.2 ± 11.23). Overall, the Pearson's correlation between differences in length and divided function of kidney pairs was 0.1630, P = 0.0058. Of 73 with significant difference (> 10%) in divided function, 18 (24.7%) had no difference in kidney length; 54 (74%) had a difference of < 2 cm and only one of > 2 cm. Using a length difference of > 1 cm would only predict significant difference in divided function in 8/34 (23.5%) of cases. Using a difference of > 2 cm as cut off for performing split function would lead to false reassurance in 72 patients (6 had > 20% difference in divided function whereas 66 had 10%-20% difference). CONCLUSION: Length difference between kidney pairs alone is not sufficient to replace measurement of divided function. This issue requires a randomised controlled trial to resolve it.

Adoption of transposed basilic vein as access for hemodialysis.

The fistula first initiative has rekindled interest in transposition of basilic vein (TBV) in preference to arteriovenous grafts (AVG). TBV is considered to have advantages over AVG. The aim of this study was to analyze the outcome of TBVs in our center comparing them to a historically matched group of patients who had AVG. Thirty-two patients who underwent TBV as a vascular access procedure in Derriford Hospital between January 2010 and October 2014 were included in the study. The historical control group comprised 31 patients who had AVG inserted in the upper arm between January 1999 and December 2010. Patients who had looped AVG were excluded from the study. The primary failure rates were 22% (7/32) and 16% (5/31) for TBV and AVG, respectively (P = 0.7500). AVGs were associated with a higher incidence of infection and steal syndrome, but the differences were not statistically significant (P = 0.286 and P = 0.286, respectively). Twenty-two interventions were undertaken in the TBV group compared to 18 in the AVG group. This study shows that adoption of TBV reduces the need for AVG. To improve TBV access maturation and survival, it is necessary to consider adopting a selection criteria based on findings on vessel mapping.

Recurrent spontaneous pneumoperitoneum: A surgical dilemma.

INTRODUCTION: Spontaneous pneumoperitoneum describes free air within the peritoneal cavity in the absence of iatrogenic causes or a perforated viscus. This report describes a rare case in which despite raised inflammatory markers, a trial of conservative management proved adequate. CASE REPORT: AM is a 36-year old woman who presented multiple times with abdominal pain and radiologically proven pneumoperitoneum. Her medical history included self catheterisation and cerebrovascular stenosis (Moyamoya disease), asymptomatic gallstones, livedo reticularis and peptic ulceration. On her index admission she exhibited raised inflammatory markers and fever. Despite these findings, emboldened by similar presentations in the past with no cause found, she declined surgical intervention with no untoward consequences. DISCUSSION: Most patients presenting with non-surgically induced pneumpoeritoneum display signs of peritonism including pyrexia and raised inflammatory markers. For such patients, surgical intervention is usually required to find and rectify the cause. CONCLUSION: A trial of conservative management may be appropriate in patients with spontaneous pneumoperitoneum but it must always be borne in mind that clinical deterioration represents an indication for surgical intervention.

Total parathyroidectomy in patients with chronic kidney disease: Avoiding repeat surgery.

Renal hyperparathyroidism (RHPT) is a common complication of renal failure and it is associated with significant morbidity and mortality. The aim of this study was to determine the patient characteristics which might predict persistent or recurrent hyperparathyroidism after surgery and to assess the long-term effect of unsuccessful surgery. This is a retrospective study of all chronic kidney disease patients who required a total parathyroidectomy (TP) because of failed medical management from January 1999 to December 2014. Patient characteristics, preoperative imaging, operative findings, and patient outcome were all studied. Differences between groups (dialysis-dependent and nondialysis-dependent; preoperative imaging and no imaging) were tested by the Chi-square statistic test and P <0.05 was regarded statistically significant. Eighty-eight patients underwent TP during this period and were followed up for a median of 35.5 months (range 1-119 months). Seventy (80%) had removal of all parathyroid glands with associated fall in parathyroid hormone level. There were no statistically significant differences in surgical success rates in neither the dialysis-dependent versus nondialysis-dependent groups nor the preoperative imaging versus no imaging groups. Two patients underwent repeat parathyroid surgery for persistent hyperparathyroidism and 16 were followed up without surgery. Preoperative imaging did not direct surgical management nor reduce surgical failure rate in this series. The long-term effects of pharmaceutical developments in this area are unknown but are likely to change indications for initial parathyroidectomy and reoperation. An agreed protocol is essential for the management of patients with RHPT.

Severe hemorrhage complicating early transplant nephrectomy due to sepsis.

Compared to the general population, transplant patients receiving immuno- suppression have an increased risk of wound and systemic infection that might lead to hemorrhage. We present a case of severe bleeding from the external iliac artery secondary to a pelvic abscess following renal transplantation and transplant nephrectomy. A 73-year-old man received an extended criteria donor organ from a 49-year-old person who died from systemic sepsis. The patient bled from the Carrel's patch while awaiting a computed tomographic scan- guided drainage of an infected peritransplant collection. At exploration, a nonviable allograft surrounded by about 1 L of thick pus was removed. Bleeding from a 2 mm hole in the Carrel's patch was repaired by prolene suture as the external iliac vessels could not be mobilized due to a frozen pelvis. The patient died 72 h later from a massive bleed confirmed at postmortem to have originated from the external iliac artery distal to the anastomosis. Diversion of blood flow away from an affected area (with or without excision of the infected vessels) through a bypass procedure probably represents the best option in avoiding such sequelae.

Transplant nephrectomy - A single-center experience.

Transplant nephrectomy (TN) is associated with significant morbidity and mortality and influences the outcome of subsequent renal transplantation. The aim of this study was to identify the reasons for TN in a single transplant center in the United Kingdom and to determine the complication rate, effect on relisting and re-transplantation. We studied all the TNs in our center from January 2000 to December 2011. Detailed information including cause of allograft failure and reason for TN were analyzed. Of 602 renal transplants performed at our center during the period of the study, 42 TNs were performed on 38 (6%) patients (24 men and 14 women). The median age of the patients at the time of transplantation who subsequently underwent TN was 56 years (range: 28-73 years) and 71% of the allografts were donated after circulatory death. The mean human leucocyte antigen mismatch for these patients was 2.3. The most commonly used immunosuppression was a combination of prednisolone, mycophenolate and tacrolimus, which was used in 50% of the patients. Twenty-five (60%) of the TNs in this series were for allografts failing during the first month of transplantation. The most common indication for the TN was graft thrombosis (50%), with an overall in-hospital mortality rate of 9.5% and a morbidity rate of 31%. Seven of 19 patients listed underwent successful re-transplantation. Although TN is associated with a risk of significant morbidity and mortality, it does not preclude from listing for re-transplantation. The difficulty of access to complete information about transplant failures and TN highlights the need for a national registry.

Current management of autosomal dominant polycystic kidney disease.

Autosomal dominant polycystic kidney disease (ADPKD), the most frequent cause of genetic renal disease affecting approximately 4 to 7 million individuals worldwide and accounting for 7%-15% of patients on renal replacement therapy, is a systemic disorder mainly involving the kidney but cysts can also occur in other organs such as the liver, pancreas, arachnoid membrane and seminal vesicles. Though computed tomography and magnetic resonance imaging (MRI) were similar in evaluating 81% of cystic lesions of the kidney, MRI may depict septa, wall thickening or enhancement leading to upgrade in cyst classification that can affect management. A screening strategy for intracranial aneurysms would provide 1.0 additional year of life without neurological disability to a 20-year-old patient with ADPKD and reduce the financial impact on society of the disease. Current treatment strategies include reducing: cyclic adenosine monophosphate levels, cell proliferation and fluid secretion. Several randomised clinical trials (RCT) including mammalian target of rapamycin inhibitors, somatostatin analogues and a vasopressin V2 receptor antagonist have been performed to study the effect of diverse drugs on growth of renal and hepatic cysts, and on deterioration of renal function. Prophylactic native nephrectomy is indicated in patients with a history of cyst infection or recurrent haemorrhage or to those in whom space must be made to implant the graft. The absence of large RCT on various aspects of the disease and its treatment leaves considerable uncertainty and ambiguity in many aspects of ADPKD patient care as it relates to end stage renal disease (ESRD). The outlook of patients with ADPKD is improving and is in fact much better than that for patients in ESRD due to other causes. This review highlights the need for well-structured RCTs as a first step towards trying newer interventions so as to develop updated clinical management guidelines.

Review of transposed basilic vein access for hemodialysis.

BACKGROUND: There is ongoing debate about the use of transposed basilic vein (TBV) fistula and the choice between it and prosthetic arteriovenous graft (AVG). This paper reviews the available literature relating to TBV fistula in terms of surgical technique, patency rates, complications, access survival and compares it with prosthetic AVG for hemodialysis (HD). METHODS: Review of English language publications on TBV during the last two decades. FINDINGS: The rate of fistula maturation was higher in the two-stage group, although the mean diameter of the basilic vein was smaller. Dialysis via central venous catheters at time of surgery was most prevalent in patients undergoing staged procedures­14% in one-stage TBV and 43% in two-stage TBV. Several authors report 1-year cumulative patency rate of 47% to 96% and 59% to 90% for TBV and AVG, respectively. TBV provides a more cost-effective option and should be considered the next choice when primary autogenous fistulae are not possible, whereas AVGs are easier to create, can be punctured earlier and have a greater reintervention rate if the access fails. CONCLUSIONS: This analysis shows that TBV has several advantages over AVG and provides a valuable access for HD but raises the need for a comparative trial between TBV and the newer generation AVGs. There is no clear superiority of the one-stage over the two-stage procedure.

Rupture of renal transplant.

Background. Rupture of renal allograft is a rare and serious complication of transplantation that is usually attributed to acute rejection, acute tubular necrosis, or renal vein thrombosis. Case Presentation. LD, a 26-year-old male with established renal failure, underwent deceased donor transplantation using kidney from a 50-year-old donor with acute kidney injury (Cr 430 mmol/L). LD had a stormy posttransplant recovery and required exploration immediately for significant bleeding. On day three after transplant, he developed pain/graft swelling and another significant haemorrhage with cardiovascular compromise which did not respond to aggressive resuscitation. At reexploration, the renal allograft was found to have a longitudinal rupture and was removed. Histology showed features of type IIa Banff 97 acute vascular rejection, moderate arteriosclerosis, and acute tubular necrosis. Conclusion. Possible ways of avoiding allograft rupture include use of well-matched, good quality kidneys; reducing or managing risk factors that would predispose to delayed graft function; ensuring a technically satisfactory transplant procedure with short cold and warm ischemia times; and avoiding large donor-recipient age gradients.

Small bowel stricture as a late sequela of superior mesenteric vein thrombosis.

INTRODUCTION: The increasing frequency of use of CT in patients with acute abdomen is likely to improve the diagnosis of rarely occurring conditions/causes such as superior mesenteric vein thrombosis (MVT). Despite its severe consequences, MVT often presents with nonspecific clinical features. PRESENTATION OF CASE: AD, a 64-year-old man was an emergency admission with vague abdominal discomfort of two weeks duration, acute upper abdominal pain, loose stools, fresh rectal bleeding and vomiting. A contrast enhanced abdominal CT showed thrombosis of the proximal portal vein and the entire length of the superior mesenteric vein (SMV) with small bowel ischaemia extending from the terminal ileum to the mid jejunal loops. Tests for paroxysmal nocturnal haemoglobinuria and Janus kinase 2 mutation yielded negative results. AD was readmitted seven months later with small bowel obstruction requiring segmental small bowel resection with end-to-end anastomosis. Abdominal CT had shown complete resolution of MVT but a small bowel stricture. DISCUSSION: Thrombosis limited to mesenteric veins results in earlier and more frequent development of infarction compared to portal combined with mesenteric venous thrombosis. Most patients may be successfully treated with anti-coagulation therapy alone. However, surgery may be required to deal with intestinal infarction or late sequela of MVT. CONCLUSION: This case demonstrates that MVT can be reversed by effective anticoagulation. However, the price paid for a mild to moderate effect on the bowel may be significant stricture later on. Patients escaping early bowel resection due to massive MVT leading to bowel infarction may still require resection later due to stricture.