Simultaneous Pancreas–Kidney Transplant

Introduction

If you are living with type 1 diabetes and your kidneys have failed or are close to failing, you have probably already had long conversations with your doctors about dialysis, kidney transplant, and what comes next. A simultaneous pancreas–kidney transplant, often shortened to SPK, is one of the options that may have come up.

SPK is a single operation in which a donor pancreas and a donor kidney are placed into your body. For carefully selected patients, it can do something that no other treatment for type 1 diabetes does: it can end the need for insulin injections and dialysis at the same time, and in many cases for many years.

It is also major surgery. It carries real risks, demands lifelong medication, and requires a serious commitment to follow-up. This guide is written for people who have already been told that SPK may be an option, or who are being assessed for it. It walks through what the operation is, who is considered a candidate, how the surgery is performed, what recovery looks like, the risks, and what life tends to look like in the months and years afterward.

The aim is to help you walk into the conversations with your transplant team with a clearer sense of what to ask and what to expect. The final decisions about whether SPK is the right path for you, and how it is timed, remain a clinical conversation between you and your specialists.

What Is a Simultaneous Pancreas–Kidney Transplant?

A simultaneous pancreas–kidney transplant (SPK) is an operation in which a healthy pancreas and a healthy kidney, both taken from the same deceased donor, are transplanted into a single recipient during one surgery.

It is performed almost exclusively in people who have:

• Type 1 diabetes — an autoimmune condition in which the pancreas no longer makes insulin, the hormone that controls blood sugar.
• End-stage kidney disease — kidney failure severe enough to need dialysis or to be approaching that point.

In most cases the two conditions are linked: years of diabetes have damaged the small blood vessels in the kidneys (a complication called diabetic nephropathy), and the kidneys have gradually lost their ability to filter the blood.

The transplanted kidney takes over the job of filtering waste and balancing fluid in the body. The transplanted pancreas begins producing insulin again, so the body can regulate blood sugar on its own. Your own pancreas and kidneys are usually left in place — they are not removed unless there is a specific reason to do so.

SPK is one of three main forms of pancreas transplantation:

• Simultaneous pancreas–kidney (SPK) — both organs in one operation, from one donor.
• Pancreas after kidney (PAK) — a pancreas transplant performed later, after a successful kidney transplant.
• Pancreas transplant alone (PTA) — for people with severe diabetes complications but without kidney failure.

Internationally, SPK is by far the most common of the three. Major transplant societies, including the International Pancreas and Islet Transplant Association (IPITA), describe SPK as the preferred option for most people with type 1 diabetes and kidney failure who are medically suitable for the operation, because pancreas graft survival has historically been better than after PAK or PTA.

Why Is SPK Performed?

SPK is performed to treat two serious problems at once. The goals are practical and concrete.

Restoring kidney function

End-stage kidney disease means the kidneys can no longer clean the blood adequately. Without treatment, waste products build up, fluid balance breaks down, and the condition becomes life-threatening. The options are dialysis (filtering the blood by machine, usually several times a week) or a kidney transplant. A transplant generally offers better long-term quality of life and survival than long-term dialysis for people who are suitable candidates.

Ending insulin dependence

In type 1 diabetes, the immune system has destroyed the insulin-producing cells in the pancreas. People with type 1 diabetes need insulin injections or an insulin pump every day for the rest of their lives. Despite very careful management, blood sugar can still swing high and low, and the long-term damage to blood vessels, nerves, eyes, and kidneys is hard to fully prevent.

A successfully working transplanted pancreas produces insulin in response to the body’s own signals, just as a healthy pancreas does. Most people with a well-functioning pancreas graft no longer need insulin injections and no longer experience severe hypoglycaemia (dangerously low blood sugar).

Slowing or improving diabetes complications

Beyond stopping insulin injections, normal blood sugar control after a successful pancreas transplant appears to slow, stabilise, or in some cases improve other complications of diabetes — including nerve damage (neuropathy), some aspects of eye disease (retinopathy), and damage to the small blood vessels. The new kidney also avoids being damaged in the same way the original kidneys were.

Quality of life

For many people, the combination of no dialysis and no insulin injections is a profound day-to-day change. Energy levels, diet flexibility, work, travel, and sleep are often affected for the better. These benefits have to be weighed against the burden of surgery, lifelong medication, and follow-up.

Who Is a Candidate for SPK?

Not everyone with type 1 diabetes and kidney failure is a candidate for SPK. Transplant teams assess candidates carefully because the surgery is long and complex, and because the medications taken afterward have important effects on the rest of the body.

Doctors typically consider SPK for adults with:

• Type 1 diabetes, confirmed by clinical history and testing.
• Advanced chronic kidney disease, often defined as a glomerular filtration rate (a measure of kidney function) below a set threshold, or already on dialysis.
• Adequate heart and lung function to safely tolerate a long operation under general anaesthesia.
• No active infection or recent cancer.
• Ability and willingness to take immunosuppressive medications every day, for life, and to attend frequent follow-up.

SPK may also be considered in some adults with type 2 diabetes who have kidney failure, are on insulin, and meet specific criteria such as a relatively low body mass index and good cardiovascular fitness. The role of pancreas transplantation in type 2 diabetes is more limited and is decided case by case.

Factors that may make SPK less suitable, or that need to be addressed first, include:

• Significant untreated heart disease — people with long-standing diabetes often have coronary artery disease that needs to be evaluated and sometimes treated before transplant.
• Severe peripheral vascular disease, which can make the surgical connections to blood vessels more difficult.
• Active or recent cancer.
• Active substance use disorders, which can affect medication adherence.
• Severe untreated psychiatric illness.
• Frailty or other medical conditions that make a long operation unsafe.

Many of these factors are not absolute — some can be treated or improved before transplant. The transplant team’s evaluation is designed to identify what is fixable and what is not.

Alternatives to SPK

SPK is one option among several. The right path depends on your kidney function, your heart and overall health, donor availability, and your own preferences. The main alternatives that may be discussed include:

Kidney transplant alone

If a living donor kidney is available (for example, from a family member), a kidney-alone transplant can be performed relatively quickly, often without a long wait. The kidney is replaced, but diabetes management continues with insulin. Some people choose this path because the waiting time is shorter, or because a suitable living donor is available, or because they prefer not to undergo a longer, more complex operation. A pancreas transplant can sometimes be considered later (a PAK).

Kidney transplant from a deceased donor

If no living donor is available, a deceased-donor kidney transplant alone is another option. Waiting times depend on local allocation systems.

Long-term dialysis

For people who are not candidates for transplant, or who prefer not to undergo one, dialysis remains an option for treating kidney failure. Dialysis sustains life but does not address diabetes and is associated with a higher long-term burden than transplant for most candidates.

Intensive diabetes management

For diabetes itself, modern tools — continuous glucose monitors, insulin pumps, and hybrid closed-loop systems — have significantly improved day-to-day control for many people with type 1 diabetes. These do not reverse kidney damage that has already happened, and they do not remove the need to inject or infuse insulin, but they are an important part of care before transplant and may be enough on their own for people whose kidneys are still working well.

Islet cell transplantation

Islet transplantation involves transplanting only the insulin-producing cells of the pancreas, not the whole organ. It is less invasive than whole-pancreas transplant but is not as widely available, often requires more than one infusion, and results have historically been less durable than whole-organ SPK. Availability varies considerably between countries and centres.

SPK is performed as an open operation through an incision in the lower abdomen. The complexity of placing two organs and connecting them to blood vessels and to the digestive or urinary tract means that minimally invasive approaches (laparoscopic or robotic) are not standard for SPK.

Within the open approach, the surgical team makes several specific decisions:

Where the organs are placed

The donor kidney is typically placed in the lower abdomen on one side, often the left, and the donor pancreas on the other side, often the right. The exact positioning depends on the patient’s anatomy and the surgeon’s preference.

Enteric versus bladder drainage of the pancreas

The donor pancreas comes with a small segment of the donor’s small intestine attached (the duodenum), because the pancreas normally drains its digestive juices through this segment. The surgeon has to decide where to drain this fluid:

• Enteric drainage connects the donor duodenum to the recipient’s own small intestine. This is the more common approach today and is considered more physiological.
• Bladder drainage connects the donor duodenum to the bladder. This was historically more common and has the advantage of allowing pancreas function to be monitored through the urine, but it can cause urinary complications over time.

Systemic versus portal venous drainage

The venous outflow of the transplanted pancreas can be connected either to a major vein returning to the heart (systemic drainage) or to the portal venous system, which carries blood to the liver (portal drainage, considered more natural). Both are used; choice depends on the centre and the case.

These technical choices are made by the surgical team. They influence some details of recovery and long-term monitoring, but for most patients the overall experience and outcomes are broadly similar.

Preparing for SPK

Preparation for SPK has two phases: the formal evaluation to confirm you are a candidate, and the waiting period before a suitable donor organ becomes available.

Transplant evaluation

The evaluation is thorough and usually takes place over several visits. It typically includes:

• Detailed history and physical examination, including how long you have had diabetes, kidney function trends, medications, and other health conditions.
• Blood tests — kidney function, liver function, blood counts, blood sugar and HbA1c, C-peptide (a test of how much insulin your own pancreas is still making), and screening for hepatitis B and C, HIV, tuberculosis, and other infections.
• Cardiac assessment — ECG, echocardiogram, and often a stress test or coronary angiography, because heart disease is common in people with long-standing diabetes and kidney failure.
• Pulmonary assessment if there is any concern about lung function.
• Imaging of the abdomen and pelvis, and vascular imaging to confirm that the blood vessels where the new organs will be connected are healthy enough.
• Dental assessment, to identify any sources of infection before transplant.
• Cancer screening appropriate for age and sex.
• Immunological testing — blood group, HLA tissue typing, and a screen for antibodies that could attack a donor organ.
• Psychological and social assessment — to understand your support system, your ability to manage complex medication regimens, and any concerns that need to be addressed.

The transplant team meets together to review the results. If you are accepted as a candidate, you are placed on the waiting list.

While waiting

The waiting time for a donor pancreas and kidney pair from a deceased donor can vary considerably, from months to a few years, depending on blood group, antibody levels, donor availability, and local allocation rules. During this time, the focus is on:

• Maintaining diabetes control as well as possible.
• Continuing dialysis if needed, or planning for its start if kidney function is still declining.
• Staying as fit as possible — nutrition, exercise within your limits, vaccinations, and dental care.
• Updating tests as the team requests, so you are ready when an organ becomes available.

You will usually be asked to be reachable at short notice, because a donor offer can come at any time and the operation needs to start within hours.

What Happens During the Surgery

When suitable donor organs become available and you are called in, the team confirms a final round of tests, including a crossmatch with the donor’s blood to check compatibility. If everything is in order, the operation proceeds.

In broad terms, the steps include:

1. An incision in the lower abdomen.
2. Preparation of the recipient’s major blood vessels in the pelvis (the iliac vessels) where the new organs will be connected.
3. Implantation of the donor kidney — connecting its artery and vein to your iliac vessels, and connecting its ureter to your bladder. Once the clamps are released, the kidney often begins producing urine quickly.
4. Implantation of the donor pancreas — connecting its blood vessels to your iliac vessels (or portal system) and connecting the attached segment of donor duodenum either to your small intestine (enteric drainage) or to your bladder (bladder drainage).
5. Careful checks for bleeding, good blood flow to both organs, and watertight connections.
6. Placement of drains and closure of the incision.

Throughout the operation, the anaesthetic team monitors blood pressure, fluid balance, and blood sugar closely. Insulin is often still being given during surgery, with the dose reduced as the new pancreas starts to work.

Recovery and Healing

Immediately after surgery

You wake up in an intensive care unit (ICU) or a specialised transplant unit. Typical features of the first few days include:

• A breathing tube may be in place initially and is usually removed within the first day.
• Drips and lines deliver fluids, antibiotics, immunosuppressive medication, and pain relief.
• A urinary catheter measures urine output closely — an important sign of how the new kidney is working.
• Blood sugar is checked frequently. Many people no longer need insulin within hours or days of surgery, as the new pancreas takes over. Some need short-term insulin while the pancreas “wakes up”.
• Blood tests are done several times a day to monitor kidney function, pancreas enzymes, and immunosuppression levels.

ICU stays are commonly a few days. The total hospital stay is often around two to three weeks, but it varies based on individual recovery and any complications.

The first weeks at home

Once you are discharged, the focus shifts to monitoring for rejection and infection, adjusting immunosuppressive drugs, and rebuilding strength. Clinic visits are frequent at first — often several times a week — and gradually spaced out.

During this phase you can expect:

• Frequent blood tests.
• Adjustments to medication doses.
• A gradual return to normal eating, with guidance from a dietitian.
• Restrictions on heavy lifting and driving while the abdominal wound heals.
• Fatigue, which is normal after a long operation and a long illness leading up to it.

Three to twelve months

By around three months, many people feel substantially stronger. Blood sugar is typically controlled without insulin, kidney function is stable, and dialysis is no longer needed. Clinic visits become less frequent. Energy improves. Travel and work usually resume during this period, depending on the kind of work and any complications.

By six to twelve months, most of the early risk has passed, although follow-up continues for life.

Immunosuppression

The body’s immune system normally attacks anything it recognises as foreign — including transplanted organs. Immunosuppressive medication damps down this response so that the new pancreas and kidney are not rejected.

A typical regimen includes a combination of medications, given in higher doses at the start (induction) and then at lower maintenance doses long-term. Commonly used drugs include:

• A calcineurin inhibitor, usually tacrolimus.
• An antiproliferative agent, usually mycophenolate.
• Corticosteroids (such as prednisolone), sometimes used short-term and sometimes long-term, depending on the protocol.
• Induction agents given around the time of surgery, such as antibody preparations.

These medications are essential, but they have side effects. They can increase the risk of infection, raise blood pressure, affect kidney function, raise blood sugar (occasionally re-introducing some insulin need), thin the bones over time, and increase the long-term risk of certain cancers, particularly skin cancers and lymphomas. The transplant team monitors blood levels of the drugs and adjusts doses to balance these risks against the need to protect the grafts.

Risks and Complications

SPK is one of the larger operations in modern transplant surgery, and it carries a meaningful risk of complications. Knowing the main ones in advance makes it easier to recognise problems early.

Surgical complications

• Bleeding, sometimes requiring a return to the operating room.
• Pancreas graft thrombosis — clotting of the blood vessels feeding the new pancreas. This is the most common cause of early pancreas graft loss and is a recognised risk specific to pancreas transplantation.
• Leak from the connection between the donor duodenum and the recipient’s intestine or bladder.
• Infection of the surgical site or inside the abdomen.
• Pancreatitis of the graft (inflammation of the new pancreas), particularly in the early days.
• Wound healing problems, more common in people with diabetes.
• Urological complications with the new kidney, such as leaks or narrowing of the ureter.

Rejection

Both the new kidney and the new pancreas can be rejected by the immune system. Rejection can be acute (in the first weeks to months) or chronic (slowly, over years). Acute rejection is usually treatable if caught early, which is why frequent blood tests in the first months matter. Rejection of the kidney is often detected through a rise in creatinine; rejection of the pancreas is harder to detect early and is sometimes confirmed by biopsy.

Infection

Because the immune system is suppressed, transplant recipients are at higher risk of bacterial, viral, and fungal infections. Some, like cytomegalovirus (CMV), are specifically watched for and may be treated preventively.

Side effects of medications

As described above, immunosuppressive drugs can affect kidney function, blood pressure, blood sugar, bone density, and long-term cancer risk. Regular monitoring is part of routine follow-up to catch these effects early.

Cardiovascular events

People who come to SPK often have long-standing diabetes and a history of cardiovascular risk. Heart attacks and strokes remain important risks both around the time of surgery and in the years afterward, and cardiovascular care continues to be a central part of long-term follow-up.

Life After SPK

That said, “cured” is not the right word. SPK replaces one set of daily tasks (insulin, dialysis, blood sugar checks) with another (immunosuppression, regular blood tests, infection awareness, sun protection, and lifelong clinic visits). Long-term success depends largely on how consistently you take medication and engage with follow-up.

Diet and nutrition

In the early weeks after surgery, dietitians often advise:

• Enough protein to support healing.
• Controlled salt intake, particularly while blood pressure and kidney function are stabilising.
• Plenty of fluids unless restricted.
• Care with food hygiene — avoiding raw or undercooked meat, eggs, and seafood, and being cautious with unpasteurised dairy and certain soft cheeses, because of infection risk on immunosuppression.

Longer term, a balanced diet that supports healthy weight, normal blood pressure, and heart health is encouraged. Although insulin may no longer be needed, attention to overall metabolic health remains important.

Exercise and activity

Once the surgical wound has healed and the team gives clearance, regular physical activity is encouraged. It supports cardiovascular health, bone density, mood, and weight control. The pace of return is individual.

Work, travel, and relationships

Many recipients return to work within a few months. Travel is possible with planning — vaccinations, a supply of medication, and an understanding of where to seek care if needed. Pregnancy after transplant is possible for some women and is planned carefully with the transplant and obstetric teams, often after a stable period post-transplant.

Infection awareness and vaccinations

Transplant recipients are advised to keep vaccinations up to date (with attention to which vaccines are safe on immunosuppression — live vaccines are generally avoided), to be careful with sources of infection, and to seek care early when unwell. Skin protection and regular skin checks become important because of the long-term increased risk of skin cancer.

Long-term follow-up

Follow-up continues for life. Visits become less frequent over time but never stop. Routine monitoring includes:

• Kidney function tests.
• Blood sugar and HbA1c.
• Pancreas enzyme levels.
• Immunosuppressant drug levels.
• Screening for infections such as CMV and BK virus, especially in the first year.
• Blood pressure and cholesterol management.
• Cancer screening — skin in particular, and other age-appropriate screening.
• Bone health assessment.

Outcomes after SPK in experienced centres are generally good. Most recipients have functioning kidney and pancreas grafts at one year, and a substantial proportion have grafts still working at five and ten years. Outcomes have improved over time as surgical technique and immunosuppression have evolved. Specific long-term numbers should be discussed with your own transplant team, since they depend on individual factors — age, other health conditions, donor characteristics, and how the early post-transplant period goes.

Frequently Asked Questions

Will I really be able to stop insulin?

In most successful SPK cases, yes — insulin injections are no longer needed once the new pancreas is working. Some people need short-term insulin in the first days or weeks, and a small number need it again later if the pancreas graft function declines or if steroid medications raise blood sugar.

Why are both organs transplanted at the same time?

Doing both at once means a single major operation, one donor, one course of induction immunosuppression, and shared immunological compatibility between the two organs. Pancreas graft survival has historically been better in SPK than when the pancreas is transplanted later as a separate operation (PAK).

Are my own pancreas and kidneys removed?

Usually no. The donor organs are placed in addition to your own, in the lower abdomen. Your own organs are left in place unless there is a specific reason to remove them.

How long is the operation?

SPK typically takes somewhere between six and twelve hours, depending on the complexity of the case.

How long will I be in hospital?

A typical hospital stay is about two to three weeks, including time in the intensive care unit. Some patients go home earlier and some need to stay longer, depending on recovery and complications.

Will I need medication for life?

Yes. Immunosuppressive medications must be taken every day for as long as the transplanted organs are in place. Stopping them, even briefly, can trigger rejection and lead to loss of the grafts.

What happens if one of the organs is rejected?

Acute rejection of the kidney or pancreas is often treatable, especially when detected early through routine blood tests. Treatment usually involves stronger immunosuppressive medications for a short period. Chronic rejection is harder to reverse and is one of the main reasons grafts can fail years later.

Can SPK reverse the complications of diabetes?

It can stabilise or improve some complications, particularly nerve damage and some aspects of small-vessel disease, by restoring normal blood sugar control. Damage that has already happened to eyes, nerves, or large blood vessels does not always fully reverse. The new kidney avoids being damaged in the way the original kidneys were.

Where do the donor organs come from?

In SPK, the pancreas and kidney almost always come from a deceased donor. Living-donor pancreas transplantation is technically possible but very rarely performed because of the risk to the donor.

Is SPK performed in children?

SPK is overwhelmingly an adult operation. Children and adolescents with type 1 diabetes and kidney failure are usually managed with kidney transplantation and continued insulin therapy, because the benefits and risks of pancreas transplantation are weighed differently in younger patients. Decisions in this age group are made by specialist paediatric transplant teams.

How is SPK different from islet cell transplantation?

Whole-pancreas transplantation places the entire organ in the body and connects it surgically. Islet cell transplantation infuses only the insulin-producing cells, usually into the liver, through a less invasive procedure. Whole-organ SPK has generally produced more durable freedom from insulin but is a much larger operation. Availability of islet transplantation varies widely.

Conclusion

A simultaneous pancreas–kidney transplant is one of the most significant operations in modern transplant medicine. For people with type 1 diabetes and kidney failure who are suitable candidates, it offers something no other single treatment does: the possibility of life without dialysis and without insulin injections, often for many years.

It is also a serious undertaking. The operation is long, the risks are real, and the commitment to immunosuppression and follow-up is lifelong. Outcomes have improved substantially over the years, and experienced transplant teams are able to guide candidates through evaluation, surgery, and the months and years that follow.

If SPK has been raised as an option for you, the most useful next step is a detailed conversation with a transplant team about your specific situation — your kidney function, your heart health, your diabetes history, and your goals. The decisions that follow are individual, but they are easier to make with a clear picture of what the operation is, what it asks of you, and what it can offer.