22- Oncology & Transplant Explains Flashcards
1
Q
What is the breakthrough dose of morphine in relation to the daily dose?
A
The breakthrough dose of morphine is one-sixth of the daily dose of morphine.
2
Q
What should be prescribed to all patients receiving opioids?
A
All patients receiving opioids should be prescribed a laxative.
3
Q
Should opioids be used with caution in patients with chronic kidney disease?
A
Yes, opioids should be used with caution in patients with chronic kidney disease.
4
Q
Which opioids are preferred in palliative care prescribing for pain?
A
Alfentanil, buprenorphine, and fentanyl are preferred opioids in palliative care prescribing for pain.
5
Q
What are the possible treatment options for metastatic bone pain?
A
Metastatic bone pain may respond to NSAIDs, bisphosphonates, or radiotherapy.
6
Q
By how much should the next dose of opioids be increased when increasing the dose?
A
The next dose of opioids should be increased by 30-50% when increasing the dose.
6
Q
How do you convert from oral codeine to oral morphine?
A
To convert from oral codeine to oral morphine, divide the dose by 10.
7
Q
How do you convert from oral tramadol to oral morphine?
A
To convert from oral tramadol to oral morphine, divide the dose by 5.
8
Q
How do you convert from oral morphine to oral oxycodone?
A
To convert from oral morphine to oral oxycodone, divide the dose by 2.
9
Q
What is the approximate equivalent dose of oral morphine sulphate (80-90mg over 24 hours) to one ‘25 mcg/hour’ fentanyl patch?
A
The approximate equivalent dose of oral morphine sulfate (80-90mg over 24 hours) to one ‘25 mcg/hour’ fentanyl patch can be found in the product literature and should be consulted.
10
Q
How do you convert from oral morphine to subcutaneous diamorphine?
A
To convert from oral morphine to subcutaneous diamorphine, divide the dose by 3.
11
Q
How do you convert from oral oxycodone to subcutaneous diamorphine?
A
To convert from oral oxycodone to subcutaneous diamorphine, divide the dose by 1.5.
12
Q
What is the main screening test for colorectal cancer in the NHS?
A
The main screening test for colorectal cancer in the NHS is the faecal occult blood (FOB) test, which is being replaced by FIT testing.
13
Q
What happens if a patient has abnormal results from the FOB or FIT test?
A
Patients with abnormal results are offered a colonoscopy.
14
Q
Who is eligible for colorectal cancer screening through the NHS national screening programme?
A
All men and women aged 60 to 69 years are offered screening every 2 years. Patients aged over 70 years may request screening.
15
Q
What are the findings at colonoscopy for most patients?
A
Approximately 5 out of 10 patients will have a normal exam, 4 out of 10 patients will have polyps that may be removed due to their premalignant potential, and 1 out of 10 patients will have cancer.
15
Q
What is the purpose of the NHS BOSS flexible sigmoidoscopy screening?
A
The NHS BOSS flexible sigmoidoscopy screening comprises a single flexible sigmoidoscopy for patients aged 55 years.
16
Q
What are the symptoms that indicate the need for referral for further evaluation of colorectal cancer?
A
Patients with altered bowel habit for more than six weeks, new onset of rectal bleeding, or symptoms of tenesmus should be referred for further evaluation.
17
Q
What are the options for diagnosing colorectal cancer aside from colonoscopy?
A
Other options for diagnosing colorectal cancer include double contrast barium enema and CT colonography.
18
Q
How are patients with colonic cancer staged?
A
Patients with colonic cancer are staged using chest/abdomen and pelvic CT.
19
Q
How are patients with rectal cancer evaluated for staging?
A
Patients with rectal cancer undergo evaluation of the mesorectum with pelvic MRI scanning.
20
Q
What is the preferred system for staging colorectal cancer for examination purposes?
A
The preferred systems for staging colorectal cancer for examination purposes are the Dukes and TNM systems.
21
Q
What is the main tumour marker in colorectal cancer?
A
The main tumour marker in colorectal cancer is carcinoembryonic antigen (CEA).
22
Q
Are all colorectal tumors secrete carcinoembryonic antigen (CEA)?
A
No, not all colorectal tumors secrete carcinoembryonic antigen (CEA). It may also be raised in conditions such as inflammatory bowel disease (IBD).
23
How is carcinoembryonic antigen (CEA) used in follow-up for colorectal cancer?
Carcinoembryonic antigen (CEA) levels, although not specific, roughly correlate with disease burden and are once again being used routinely in follow-up.
24
Are metastatic lesions affecting bone more common than primary bone tumors?
Yes, metastatic lesions affecting bone are more common than primary bone tumors.
25
Which are the typical tumors that spread to bone?
The typical tumors that spread to bone include breast, bronchus, renal, thyroid, and prostate tumors.
26
What is the age group most commonly affected by bone metastases?
Around 75% of cases of bone metastases affect individuals over the age of 50.
27
Which are the most common bone sites affected by metastatic lesions?
The most common bone sites affected by metastatic lesions are the vertebrae (usually thoracic), proximal femur, ribs, sternum, pelvis, and skull.
28
What type of bone lesions pose the greatest risk for pathological fracture?
Osteolytic lesions pose the greatest risk for pathological fracture.
29
How does the risk of fracture vary according to the extent of bone lesion involvement?
The risk of fracture varies according to the extent of bone lesion involvement. Bones with lesions occupying 50% or less of the bone are prone to fracture under loading, while when 75% of the bone is affected, torsion about a bony fulcrum may produce a fracture.
30
Which scoring system can be used to determine the risk of fracture in bone metastases?
The Mirel scoring system can be used to help determine the risk of fracture in bone metastases, and it is more systematic than the Harrington system.
31
What is the Mirel Scoring system used for?
The Mirel Scoring system is used to determine the risk of fracture in bone metastases.
32
What are the factors considered in the Mirel Scoring system?
The Mirel Scoring system considers points, site of the lesion, radiographic appearance, width of bone involved, and pain.
33
Can you provide an example of the Mirel Scoring system?
Score points , Site , Radiographic appearance, Width of bone involved , Pain
1 Upper extremity Blastic Less than ⅓ Mild
2 Lower extremity Mixed 1/3 to ⅔ Moderate
3 Peritrochanteric Lytic More than ⅔ Aggravated by functio
34
How is the treatment determined based on the Mirel Score?
Depending upon the score the treatment should be as follows:
Score Risk of fracture Treatment
9 or greater Impending (33%) Prophylactic fixation
8 Borderline Consider fixation
7 or less Not impending (4%) Non operative management
35
What treatment should be considered for isolated metastatic deposits?
For isolated metastatic deposits, consideration should be given to excision and reconstruction as the outcome is better.
36
What are the non-operative treatments for bone metastases?
Non-operative treatments for bone metastases include rehydration and bisphosphonates for hypercalcemia, opiate analgesics and radiotherapy for pain, and chemotherapy and/or hormonal agents for certain tumors like breast and prostate cancer.
37
What is the indication for endocrine therapy in breast cancer treatment?
Endocrine therapy is indicated for oestrogen receptor-positive tumors, downstaging primary lesions, and definitive treatment in old or infirm patients.
38
When is irradiation used in breast cancer treatment?
Irradiation is used after wide local excision and in cases of large lesions, high grade tumors, or marked vascular invasion following mastectomy.
39
Which endocrine agents are commonly used in breast cancer treatment?
Tamoxifen is commonly used as a partial oestrogen receptor agonist in breast cancer treatment. Aromatase inhibitors are preferred in postmenopausal women, while tamoxifen is initially used in perimenopausal women before switching at 3 years. Exemestane is increasingly preferred over tamoxifen in premenopausal women.
39
When is chemotherapy used in breast cancer treatment?
Chemotherapy is used to downstage advanced lesions to facilitate breast conserving surgery and in patients with grade 3 lesions or axillary nodal disease.
40
What is the most commonly used chemotherapy regime in breast cancer treatment?
The FEC regime (Fluorouracil, epirubicin, and cyclophosphamide) is most commonly used in breast cancer treatment. In high-risk patients, a regime of docetaxal, doxorubicin, and cyclophosphamide may be used.
41
What percentage of chemotherapy cases may be complicated by extravasation reactions?
Up to 6% of chemotherapy cases may be complicated by extravasation reactions.
41
What should be considered when using anthracycline class drugs in breast cancer treatment?
Anthracycline class drugs, which include trastuzumab, have marked cardiotoxicity, which can limit their use in some cases.
42
What percentage of extravasation reactions may be complicated by ulceration?
Up to 30% of extravasation reactions may be complicated by the development of ulceration.
43
Which chemotherapy agents are recognized causes of extravasation reactions?
Doxorubicin, vincristine, vinblastine, cisplatin, mitomycin, and mithramycin are recognized causes of extravasation reactions.
44
What is the recommended approach for extravasation of vinca alkaloids?
Warm compresses have been found to be beneficial in extravasation of vinca alkaloids.
45
What should be done when an extravasation reaction is suspected?
When an extravasation reaction is suspected, the infusion should be stopped, and the infusing device should be aspirated. The extremity should be elevated.
46
What is the recommended approach for reducing the incidence of subsequent ulceration with doxorubicin extravasation?
Cold compresses have been shown to reduce the incidence of subsequent ulceration with doxorubicin extravasation.
47
What can be infused in some cases of extravasation, ideally within 5 hours of the event occurring?
Dimethylsulfoxide may be infused in some cases of extravasation, ideally within 5 hours of the event occurring.
48
Are corticosteroids or sodium bicarbonate recommended for extravasation injuries?
No conclusive evidence exists to support the use of corticosteroids or sodium bicarbonate for extravasation injuries.
49
How is extravasation of total parenteral nutrition solutions usually managed?
Extravasation of total parenteral nutrition solutions is usually managed by the local administration of hyaluronidase to the infusion site.
50
How are lung cancers classified according to histological subtypes?
Lung cancers are classified into small cell and non-small cell lung cancer based on histological subtypes.
51
Which is the most common variant of lung cancer?
Non-small cell lung cancer is the most common variant, accounting for 80% of all lung cancers.
52
What are the common subtypes of non-small cell lung cancer?
The common subtypes of non-small cell lung cancer are squamous cell carcinoma (25% cases), adenocarcinoma (40% cases), and large cell carcinoma (10% cases).
53
How do non-small cell lung cancers differ from small cell lung carcinoma in terms of prognosis and features?
Non-small cell lung cancers have a lower likelihood of paraneoplastic features and early disease dissemination compared to small cell lung carcinoma.
54
Which type of lung cancer is most commonly encountered in never smokers?
Adenocarcinoma is the most common type of lung cancer encountered in never smokers.
55
What are the characteristics of small cell lung carcinoma?
Small cell lung carcinomas are comprised of cells with a neuroendocrine differentiation. They are strongly associated with smoking and typically arise in the larger airways. They disseminate early in the course of the disease and, although chemosensitive, long-lasting remissions are rare.
55
What percentage of lung cancer cases are suitable for surgery?
Only 20% of lung cancer cases are suitable for surgery.
56
Why is mediastinoscopy performed prior to surgery in non-small cell lung cancer?
Mediastinoscopy is performed prior to surgery because CT scans do not always show mediastinal lymph node involvement.
56
How do non-small cell lung cancers typically respond to chemotherapy?
Non-small cell lung cancers generally have a poor response to chemotherapy.
57
What are the treatment options for non-small cell lung cancer?
The treatment options for non-small cell lung cancer include curative or palliative radiotherapy and chemotherapy.
58
What lung function tests may be recommended if FEV1 is below the cut-off point for lobectomy or pneumonectomy?
If FEV1 is below the cut-off point for lobectomy (< 1.5) or pneumonectomy (< 2.0), some authorities may recommend further lung function tests to determine if the operations can still proceed based on the results.
59
What is the general cut-off point for FEV1 in determining surgery eligibility?
FEV1 < 1.5 liters is considered a general cut-off point for determining surgery eligibility.
59
What are the different modalities of tissue sampling?
The different modalities of tissue sampling include fine needle aspiration cytology, core biopsy, excision biopsy, Tru cut biopsy, punch biopsy, cytological smears, and endoscopic or laparoscopic biopsy.
60
What are the contraindications for surgery in non-small cell lung cancer?
The contraindications for surgery in non-small cell lung cancer include poor general health, stage IIIb or IV disease (i.e., presence of metastases), malignant pleural effusion, tumor near the hilum, vocal cord paralysis, and SVC obstruction.
61
What are the limitations of fine needle aspiration cytology (FNAC)?
Fine needle aspiration cytology can be limited by operator inexperience and the lack of histological architectural information.
61
How is fine needle aspiration cytology (FNAC) performed?
Fine needle aspiration cytology is performed by passing a needle through a lesion while applying suction to a syringe. The obtained material is expressed onto a slide and sent for cytological assessment.
62
What are core biopsy and tru cut biopsy?
Core biopsy and tru cut biopsy are methods of obtaining tissue samples. Core biopsy uses a spring-loaded gun with a needle passing quickly through the lesion, while tru cut biopsy involves manually moving the needle.
62
When is image guidance desirable for core biopsy and tru cut biopsy?
Image guidance, such as in breast lesions, may be desirable when performing core biopsy and tru cut biopsy.
63
How can visceral lesions be accessed for biopsy?
Visceral lesions can be accessed percutaneously under image guidance, such as ultrasound-guided biopsy of liver metastases, or under direct vision, such as colonoscopic biopsy.
64
What is chordoma?
Chordoma is a rare, slow-growing bone tumor that originates from remnants of the notochord.
65
Where can chordomas arise in the body?
Chordomas can arise anywhere from the skull base to the sacrum, with the most common locations being the skull base and sacrum.
66
What are the three histological variants of chordoma?
The three histological variants of chordoma are classical (or 'conventional'), chondroid, and de-differentiated.
67
How does classical chordoma appear histologically?
Classical chordoma appears histologically as a lobulated tumor composed of groups of cells separated by fibrous septa. The cells have small round nuclei and abundant vacuolated cytoplasm.
68
What are the characteristics of chondroid chordomas?
Chondroid chordomas show histological features of both chordoma and chondrosarcoma.
69
What is the 10-year tumor-free survival rate for sacral chordoma?
The 10-year tumor-free survival rate for sacral chordoma is 46%.
70
What is the recommended treatment approach for chordoma?
In most cases, complete surgical resection followed by radiation therapy offers the best chance of long-term control for chordoma.
71
Why is complete surgical resection challenging for chordomas?
Complete surgical resection of chordomas can be challenging due to their close proximity to the spine, which can compromise resection margins.
72
Why are chordomas relatively radioresistant?
Chordomas are relatively radioresistant, meaning they require high doses of radiation to be controlled.
73
What are the limitations of delivering radiation to chordomas?
The proximity of chordomas to vital neurological structures, such as the brain stem and nerves, limits the dose of radiation that can safely be delivered.
74
What are the more effective radiation therapies for chordomas?
Highly focused radiation therapies, such as proton therapy and carbon ion therapy, are more effective than conventional x-ray radiation for treating chordomas.
75
What does the Dukes classification indicate?
The Dukes classification indicates the extent of spread of colorectal cancer.
76
What does Dukes A signify?
Dukes A signifies a tumor that is confined to the bowel and does not extend beyond it, without nodal metastasis.
77
What percentage of tumors fall under Dukes A classification?
Approximately 95% of tumors fall under the Dukes A classification.
78
What does Dukes B indicate?
Dukes B indicates a tumor that has invaded the bowel wall, but does not have nodal metastasis.
79
What percentage of tumors fall under Dukes B classification?
Approximately 75% of tumors fall under the Dukes B classification.
80
What does Dukes C indicate?
Dukes C indicates the presence of lymph node metastases.
81
What percentage of tumors fall under Dukes C classification?
Approximately 50% of tumors fall under the Dukes C classification.
82
What does Dukes D indicate?
Dukes D indicates the presence of distant metastases.
83
What percentage of tumors fall under Dukes D classification?
Approximately 6% of tumors (or 25% if resectable) fall under the Dukes D classification.
84
What is the 5-year survival rate for each Dukes classification?
The 5-year survival rate varies depending on the Dukes classification, with the specific rates indicated in brackets.
85
What are the two types of sarcomas based on origin?
Sarcomas can either be bone or soft tissue in origin.
86
What are sarcomas?
Sarcomas are malignant tumors that originate from mesenchymal tissue.
87
What are examples of bone sarcomas?
Examples of bone sarcomas include osteosarcoma, Ewing's sarcoma, and chondrosarcoma.
88
What are examples of soft tissue sarcomas?
Examples of soft tissue sarcomas include liposarcoma, rhabdomyosarcoma, leiomyosarcoma, and synovial sarcoma.
88
What are some features that raise suspicion for a sarcoma?
Features that raise suspicion for a sarcoma include a large (>5cm) soft tissue mass, deep tissue or intra-muscular location, rapid growth, and a painful lump.
89
What is malignant fibrous histiocytoma?
Malignant fibrous histiocytoma is a sarcoma that can arise in both soft tissue and bone.
90
What imaging modalities are used to assess suspicious masses?
Imaging of suspicious masses should include a combination of MRI, CT, and USS (ultrasound).
91
Should blind biopsy be performed prior to imaging?
No, blind biopsy should not be performed prior to imaging. If a biopsy is required, it should be done in a way that allows the biopsy tract to be included in any subsequent resection.
92
What are some characteristics of Ewing's sarcoma?
Ewing's sarcoma is more common in males, has an incidence of 0.3/1,000,000, typically occurs between 10 and 20 years of age, and commonly affects the femoral diaphysis. It is histologically a small round tumor and often requires a combination of chemotherapy and surgery due to common blood borne metastasis.
93
What are the characteristics of osteosarcoma?
Osteosarcoma is a malignant tumor that arises from mesenchymal cells with osteoblastic differentiation. It accounts for 20% of all primary bone tumors and has an incidence of 5 per 1,000,000. It is more common in males and typically peaks in age between 15 and 30. Limb preserving surgery may be possible, and many patients receive chemotherapy.
94
What are the characteristics of liposarcoma?
Liposarcoma is a malignancy of adipocytes. It is a rare soft tissue sarcoma, with an incidence of approximately 2.5 per 1,000,000. It is most commonly located in deep areas like the retroperitoneum. Liposarcomas typically affect an older age group, usually over 40 years of age. They may be well differentiated and slow growing, but can undergo de-differentiation and disease progression. They are usually resistant to radiotherapy and often require surgical resection as the primary treatment.
95
What are the characteristics of malignant fibrous histiocytoma?
Malignant fibrous histiocytoma is a tumor characterized by a large number of histiocytes. It is also referred to as undifferentiated pleomorphic sarcoma NOS (not otherwise specified) because the cell of origin is not known. Four major subtypes are recognized: storiform-pleomorphic (70% cases), myxoid (less aggressive), giant cell, and inflammatory. Treatment usually involves surgical resection and adjuvant radiotherapy to reduce the likelihood of local recurrence.
96
What is the importance of evaluating urine output post renal transplantation?
Post renal transplantation, urine output is a crucial indicator of graft function. It is especially useful in individuals who were relatively anuric before the transplant.
97
What are the three main groups into which recipients can be divided based on graft function?
Recipients can be divided into three main groups: immediate graft function (brisk diuresis and falling serum creatinine), slow graft function (modest urine output and slowly falling creatinine levels), and delayed graft function (need for dialysis post-transplant).
98
What are the common causes of decreased urine output following renal transplantation?
Common causes of decreased urine output following surgery include hypovolemia, blocked catheter, rejection, or vascular complications.
99
What are the main vascular complications that can occur post renal transplantation?
Vascular complications can involve the donor vessels, recipient vessels, or both. Renal artery thrombosis is uncommon but can result in graft loss. Renal vein thrombosis is less common but also associated with a high incidence of graft loss. Individuals may also develop renal artery stenosis over time.
99
What are the common urological complications following renal transplantation?
Urological complications, such as leakage or obstruction, are common following renal transplantation and can occur in up to 10% of patients. The relatively poor blood supply to the transplanted ureter is the main underlying cause. Patients typically present with pain and swelling at the graft site.
100
When do lymphoceles typically occur following renal transplantation?
Lymphoceles generally occur 2 weeks or longer after surgery. They are relatively common and may be seen in up to 18% of patients. Symptoms occur due to compression of adjacent structures, such as the graft vessels, ureter, and lower limb vessels.
101
102
What are the types of graft rejection recognized?
The four types of graft rejection recognized are hyperacute, accelerated acute, acute, and chronic rejection.
103
What are the key features of hyperacute rejection?
Hyperacute rejection occurs within minutes of clamp release during surgery. It is caused by pre-formed antibodies in the recipient's blood. Immediate loss of the graft occurs as a result.
104
What are the key features of accelerated acute rejection?
Accelerated acute rejection occurs in the first few days following surgery. It involves both cellular and antibody-mediated injury. Pre-sensitization of the donor is a common cause of this type of rejection.
105
What are the key features of acute rejection?
Acute rejection is traditionally the most common type of rejection. It is seen days to weeks after surgery. Acute rejection is predominantly a cell-mediated process mediated by lymphocytes. Organ biopsy typically shows cellular infiltrates and graft cell apoptosis.
106
What are the key features of chronic rejection?
Chronic rejection is an increasingly common problem. It is characterized by graft atrophy and atherosclerosis. Fibrosis often occurs as a late event in chronic rejection.
107
What is an allograft?
An allograft refers to an organ or tissue transplant from one individual to another.
108
What are the main antigens that give rise to rejection?
The main antigens that give rise to rejection are ABO blood group, human leukocyte antigens (HLA), and minor histocompatibility antigens.
108
Why does graft rejection occur?
Graft rejection occurs because allografts have differences in genes that code for immunohistocompatibility complex genes, leading to an immune response.
109
What is the impact of ABO incompatibility on organ rejection?
ABO incompatibility can result in early organ rejection (hyperacute) due to pre-existing antibodies to other blood groups. Group O donors can donate organs to any ABO recipient, while group AB donors can only donate to AB recipients.
110
What are the four most important HLA alleles?
The four most important HLA alleles are HLA A, HLA B, HLA C, and HLA DR.
111
What is the ideal organ match in terms of HLA alleles?
The ideal organ match would be one in which all 8 alleles (2 from each parent) are matched.
112
What is the impact of HLA mismatching on organ rejection?
HLA mismatching can lead to organ rejection. The greater the number of mismatches, the worse the long-term outcome will be.
112
What occurs during acute rejection?
Acute rejection typically occurs within the first 6 months and is usually T-cell mediated. It is characterized by tissue infiltrates and vascular lesions.
113
What occurs during chronic rejection?
Chronic rejection occurs after the first 6 months. Vascular changes, such as myointimal proliferation, predominate. Organ-specific changes may also be seen.
114
Which type of transplant is at greatest risk for hyperacute rejection?
Renal transplants are at the greatest risk for hyperacute rejection. Liver transplants are at the least risk.
115
Which types of organ can undergo acute rejection?
All types of transplanted organs may undergo acute rejection. Mononuclear cell infiltrates are usually predominant.
116
Which transplants may suffer from chronic rejection with HLA mismatch?
All transplants with HLA mismatch may suffer from chronic rejection. Previous acute rejections and other immunosensitizing events increase the risk.
117
What are the prominent vascular changes seen in chronic rejection?
In chronic rejection, myointimal proliferation leads to organ ischemia. Other organ-specific changes may also occur.
117
What are the exclusion criteria for renal transplantation?
Exclusion criteria for renal transplantation include active malignancy and old age (due to limited organ availability).
118
How is laparoscopic donor nephrectomy beneficial for the donor?
Laparoscopic donor nephrectomy minimizes operative morbidity for the donor.
118
Where can donor kidneys be obtained from?
Donor kidneys can be obtained from live related donors, close family members, or brain dead/dying patients.
119
What is the key event in the donor phase of renal transplantation?
The key event in the donor phase is to minimize warm ischemic time.
120
What factors are assessed and managed when preparing the kidney for implantation?
When preparing the kidney for implantation, factors such as accessory renal arteries and vessel length are assessed and managed.
121
What is the surgical approach for first-time recipients of renal transplantation?
First-time recipients undergo the operation under general anesthesia. A Rutherford-Morrison incision is made on the preferred side to provide access to the iliac vessels.
122
What is the process of anastomosis during renal transplantation?
After systemic heparinization, the external iliac artery and vein are dissected and cross clamped. The vein and artery are then anastomosed to the iliacs.
123
What is done to maintain patency of the ureter after implantation?
After implantation, the ureter is implanted into the bladder, and a stent is usually placed to maintain patency.
124
What is a common problem encountered in cadaveric kidneys in the immediate phase?
Acute tubular necrosis is a common problem encountered in cadaveric kidneys in the immediate phase, but it tends to resolve.
125
What are the typical graft survival times for cadaveric donors and monozygotic twin transplants?
Graft survival times from cadaveric donors are typically around 9 years, while monozygotic twin transplants (live donor) may survive as long as 25 years.
126
What is an allograft?
An allograft is a transplant of tissue from a genetically non-identical donor from the same species. It is commonly used for solid organ transplants from non-related donors.
127
What is an autograft?
An autograft is the transplantation of organs or tissues from one part of the body to another in the same individual. It is commonly used for procedures such as skin grafts.
127
What is an isograft?
An isograft is a graft of tissue between two individuals who are genetically identical. It is typically used for solid organ transplants in identical twins.
128
What is a xenograft?
A xenograft is the transplantation of tissue from another species. An example of this is a porcine heart valve used in humans.
129
What are the common technical-related complications following renal transplantation?
The common technical-related complications following renal transplantation are related to the ureteric anastomosis.
130
How does warm ischemic time affect graft survival?
Graft survival is directly related to warm ischemic time. Longer warm ischemic times increase the risk of acute tubular necrosis, which can occur in all types of renal transplantation.
131
What are the types of organ rejection in renal transplantation?
The types of organ rejection in renal transplantation are hyperacute, acute, and chronic.
132
What are the risk factors for hyperacute rejection in renal transplantation?
Risk factors for hyperacute rejection in renal transplantation include major HLA mismatch and ABO incompatibility.
133
Which changes are most prominent in chronic rejection of transplanted organs?
In chronic rejection of transplanted organs, vascular changes, such as myointimal proliferation, are most prominent. Organ-specific changes may also occur.
134
What are the macroscopic features of hyperacute rejection in renal transplantation?
In hyperacute rejection, the kidney becomes mottled, dusky, and the vessels thrombose.
135
Which cells predominate in acute rejection of transplanted organs?
Mononuclear cell infiltrates predominate in acute rejection of transplanted organs.
136
What are the consequences of chronic rejection in pancreas and cardiac transplants?
In pancreas transplants, chronic rejection can lead to the loss of acinar cells. In cardiac transplants, it can result in rapidly progressive coronary artery disease.
137
What are the presenting features of renal artery thrombosis?
Renal artery thrombosis presents as a sudden complete loss of urine output.
138
What are the presenting features of renal artery stenosis?
Renal artery stenosis presents as uncontrolled hypertension, allograft dysfunction, and edema.
139
What is the recommended treatment for renal artery thrombosis?
Immediate surgery is the recommended treatment for renal artery thrombosis. Delays beyond 30 minutes are associated with a high rate of graft loss.
140
What is the treatment of choice for renal artery stenosis?
Angioplasty is the treatment of choice for renal artery stenosis.
141
What are the presenting features of urine leaks in renal transplantation?
Urine leaks in renal transplantation present with diminished urine output, rising creatinine, fever, and abdominal pain.
141
What are the presenting features of renal vein thrombosis?
Renal vein thrombosis presents with pain and swelling over the graft site, haematuria, and oliguria.
141
What is the typical outcome for renal vein thrombosis?
In most cases, the graft is usually lost in the presence of renal vein thrombosis.
142
What imaging technique is used to diagnose urine leaks in renal transplantation?
Ultrasound (USS) shows perigraft collection in cases of urine leaks. The commonest cause is necrosis of the ureter tip, and the anastomosis may need revision.
142
What is a lymphocele, and how is it managed?
A lymphocele is a common complication, occurring in 15% of cases. It may present as a mass and, if large, may compress the ureter. Lymphoceles can be drained using percutaneous techniques and sclerotherapy, or through intraperitoneal drainage.
143
What are the commonly used drugs to mitigate acute rejection in organ transplantation?
Cyclosporin and tacrolimus are commonly used drugs to mitigate acute rejection in organ transplantation.
143
What is the initial immunosuppressant regime for organ transplantation?
The initial regime typically includes ciclosporin/tacrolimus with a monoclonal antibody.
144
What is the maintenance immunosuppressant regime for organ transplantation?
The maintenance regime usually involves ciclosporin/tacrolimus with MMF or sirolimus.
145
When are steroids added to the immunosuppressant regime?
Steroids are added if there is more than one steroid-responsive acute rejection episode.
146
What is the mechanism of action of ciclosporin?
Ciclosporin inhibits calcineurin, a phosphatase involved in T cell activation.
147
What are the side effects of azathioprine?
The side effects of azathioprine include myelosuppression, alopecia, and nausea.
148
How does tacrolimus differ from ciclosporin in terms of side effects and efficacy?
Tacrolimus has a lower incidence of acute rejection compared to ciclosporin. It also has less hypertension and hyperlipidemia. However, it has a higher incidence of impaired glucose tolerance and diabetes.
149
What is the mechanism of action of mycophenolate mofetil (MMF)?
Mycophenolate mofetil (MMF) blocks purine synthesis by inhibiting IMPDH, thereby inhibiting the proliferation of B and T cells.
150
What is the mechanism of action of sirolimus (rapamycin)?
Sirolimus (rapamycin) blocks T cell proliferation by blocking the IL-2 receptor.
151
What are monoclonal antibodies used for in organ transplantation?
Monoclonal antibodies are selective inhibitors of the IL-2 receptor and are used to prevent acute rejection. Examples include daclizumab and basiliximab.
152
What is the human leukocyte antigen (HLA) system?
The HLA system refers to the major histocompatibility complex (MHC) in humans, which is coded for on chromosome 6.
153
Which antigens are included in Class 1 and Class 2 of the HLA system?
Class 1 antigens include A, B, and C, while Class 2 antigens include DP, DQ, and DR.
154
What is the relative importance of HLA antigens in renal transplant matching?
When HLA matching for a renal transplant, the relative importance of the HLA antigens is as follows: DR > B > A.
155
What are the graft survival rates for cadaveric and living-donor renal transplants?
For cadaveric transplants, the graft survival rates are 90% at 1 year and 60% at 10 years. For living-donor transplants, the rates are 95% at 1 year and 70% at 10 years.
156
What are some post-operative problems that can occur after renal transplantation?
Post-operative problems that can occur after renal transplantation include acute tubular necrosis (ATN) of the graft, vascular thrombosis, urine leakage, and urinary tract infections (UTIs).
157
What are the causes of acute graft failure within 6 months of renal transplantation?
Acute graft failure within 6 months is usually due to mismatched HLA. Other causes can include cytomegalovirus infection. Steroids are given as management, and if resistant, monoclonal antibodies may be used.
158
What is hyperacute rejection and what causes it?
Hyperacute rejection is caused by antibodies against donor HLA type 1 antigens. It is rarely seen due to HLA matching in renal transplantation.
159
What are the causes of chronic graft failure after 6 months of renal transplantation?
Causes of chronic graft failure after 6 months include chronic allograft nephropathy, ureteric obstruction, and recurrence of the original renal disease (with membranous glomerulonephritis [MCGN], IgA nephropathy, and focal segmental glomerulosclerosis [FSGS] being common).
