Vascular Surgery

Case summary
A 68-year-old male was admitted to hospital for a renal transplant for IgA nephropathy. This had been treated with peritoneal dialysis for the past 14 months. In addition to end-stage renal failure, he had multiple comorbidities including ischaemic heart disease, hypertension, hypercholesterolaemia, peripheral artery disease, hepatitis B, gout, erectile dysfunction, pyloromyotomy as a child, and depression. Previous alcoholism and heavy smoking were noted. His surgical history included laparoscopic cholecystectomy, previous rectal polyp removal and bilateral inguinal hernia repair. 

Following admission, there was no apparent preoperative anaesthetic assessment and the surgery (cadaveric renal transplant in the left iliac fossa) began at midnight (described as uneventful and of three hours duration). The Tenckhoff catheter was removed at the end of the procedure and the patient admitted to the renal ward at 05:00. After 13 hours, the patient was transferred to the intensive care unit (ICU) because of hypotension, oliguria and heavily blood-stained urine. 

Mercaptoacetyltriglycine (MAG3) renal imaging reported changes consistent with acute tubular necrosis. Over the next 24 hours, his urine output and blood pressure both improved and a renal ultrasound reported patent vessels with similar arterial velocities to the first postoperative day (POD). The patient was discharged from ICU to the renal ward 24 hours after admission.

On POD3, a MAG3 scan reported probable renal parenchymal dysfunction and possible vascular compromise. Subsequent renal ultrasound reported likely transplant renal artery stenosis with a patent renal vein. However, urine output improved during the day. 

On POD4, there was a medical emergency (MET) team call for hypotension, and the patient was transfused and readmitted to ICU. Ongoing oliguria, increasing creatinine levels and abdominal pain were noted. A further ultrasound reported increased flow velocity in the renal vein and the possibilities mentioned included stenosis, thrombosis or external compression.

Multidisciplinary discussion prompted a return to theatre that night at 20:00. The transplanted kidney was noted to be functioning satisfactorily, and the artery and vein were patent with good perfusion, but the operative notes do not make clear how this assessment was reached. A transplant biopsy was performed, and the mesh from his previous left inguinal hernia repair was incised to create more space in his left pelvis. Postoperatively, there was a four-hour delay in readmission to the ICU. While in the recovery room, the patient had a MET call due to hypotension, oliguria and increasing lactate levels. On return to ICU, note was made that the patient had no arterial line or any central venous catheter (CVC) access.

A CVC was inserted via the left femoral vein but was removed soon after on the advice of Vascular Surgery. The patient continued to deteriorate overnight, and on POD5 active bleeding into the left psoas muscle and a renal vein thrombus were reported by computed tomography with contrast. A return to theatre was delayed by two hours because no operating theatre was available.

A transplant vein thrombectomy was performed. Bleeding from the left psoas muscle was noted but no site identified. Six units of packed red blood cells were given. Continuous renal replacement therapy was requested from ICU, but the machine was not able to be delivered to theatre and so did not start until the patient had returned to ICU. On his return to ICU, he was in extremis with severe hypotension (on maximal inotropic support), worsening hypoxaemia and increased difficulty of ventilation. Major pulmonary embolism was suspected, and systemic anticoagulation initiated but this was ceased not long after when abdominal distension and wound bleeding were noted. Death occurred not long afterwards.

Discussion 
A number of observations can be made regarding this case:
1.    For a number of reasons (multiple comorbidities, late finish and major surgery) this patient may have benefited from immediate admission postoperatively to ICU for 1:1 nursing by more highly trained staff.
2.    In the absence of formal radiologist reports, the notes made mention of possible renal vascular compromise on POD3, yet the patient did not return to theatre for another 30 hours, and when he did, it was late at night. 
3.    There were significant delays of four hours in readmission to ICU after the patient's second operation and of two hours in getting the patient back to theatre for the third operation. Either or both of these may have contributed to the unfortunate outcome.
4.    Instrumentation of the iliac vein ipsilateral to the transplanted kidney during CVC insertion was ill advised and may well have contributed to both the transplant vein thrombosis and/or the bleeding from the left psoas muscle.
5.    The terminal course of events on POD 5 (likely due to pulmonary embolism) was never going to be remediated in such an unwell comorbid patient who had had major surgery.

Clinical lessons
We are increasingly seeing highly comorbid, complex patients, and for them to survive major surgery all aspects of their hospital journey need to be in place and working efficiently.  
•    Prompt access to ICU beds is vital if patients with complex ailments/ disease are to survive increasingly complex surgery. This is especially relevant for patients undergoing major surgery after hours.
•    Patients whose perioperative course is not going to plan need senior multidisciplinary decision making and also need early decisions to prevent returns to theatre at times when theatre and staff availability may be compromised.
•    Central vascular access for monitoring should always be carefully considered and completed by properly trained personnel in appropriate environments—in this case in the theatre as part of the emergency surgery rather than ICU.