Pitfalls in Veterinary Surgery

You can tell its a great read when the book is tabbed.

Professor Geraldine Hunt is a trailblazing veterinary surgeon who developed, among other things, novel surgical approaches to portosystemic shunts. In the course of her work, she’s also made errors.

Every surgeon does, but Professor Hunt has shared hers in the edited textbook Pitfalls in Veterinary Surgery, in an attempt to foster a culture of learning and improving patient outcomes.

As a former student of Professor Hunt, I sought out a copy and found this a compelling read. She discusses errors, mistakes, near-misses, but – importantly – reflects on these and considers how they can be avoided, and how outcomes can be improved, in the future. It was fascinating to read that someone so unflappable, courageous and clever was kept awake at nights by concerns that many veterinarians can relate to.

Professor Hunt took some time out to answer our questions about the book.

What is your current day job? 

I retired from full-time veterinary surgery in June 2015. My husband and I bought our 46-foot Leopard catamaran (Alchemy 1) and since then we have focussed on outfitting it for off-shore cruising. We have lots of family and friends visiting for up to 3 weeks at a time, and spend most of our time away from port so I take care of logistical things like menu planning, provisioning and making sure we we know where all our supplies are stored. I learned a lot about project management in my University positions and those skills have come in very handy. During my first year of retirement, I also spent a lot of time writing and editing the book. I also help my sister from time to time in her small animal practice.

When did you realise you would specialise in surgery? 

I originally wanted to pursue small animal medicine or cardiology (once I gave up ideas of becoming an equine vet), but my partner at the time also wanted to specialise in small animal medicine, so we felt we would be more employable as a couple of we were not both in the same discipline. During my PhD, I realised I liked the challenge and reward of surgery, so that's how things went from there.

Why did you decide to write a book about pitfalls and errors? 

I was approached about writing a conventional surgical textbook, but I felt there were a number of other texts out there that were very good, and even if they had slightly different approaches or ideas to mine, I did not feel strongly that I needed to "reinvent the wheel" so to speak. However, I had identified some other things that just did not come across in regular textbooks. I felt that a personal narrative could be useful, where the reader could get into the life and mind of a surgeon on a day-to-day basis, and hopefully gain a sense of what went on behind the scenes and the process by which I made decisions, whether they ended up being right or wrong. 

You have documented cases in great detail. Were you collecting this data as you went along, ie in the hope you might write a book like this one day? 

The thought of writing this particular book did not occur to me until about two years before I retired. Fortunately, the publisher was happy to take a risk with an unconventional style of book, and to wait until I had time to write it after I stopped working. I have always used case examples in my teaching, and have taken a lot of photographs through the years, so most of the chapters were based on a topic I had presented repeatedly in rounds or in lectures.

Do you think some degree of surgical prowess is innate, or can it be completely learned? 

Surgical prowess comes from a combination of knowledge, technical skill and temperament. You can learn the first two; the third will either help, or it will be something you need to overcome. A really good surgeon has a balance between being decisive and not too timid, and being considered and thoughtful. A good surgeon can act quickly when required, but take their time under other circumstances. This might require you to push forward when you are nervous, or hold back when you are feeling confident, and takes some people well out of their comfort zone.

What do you see as some of the common errors in veterinary surgery or practice? 

I think most errors stem from being in a rush, being tired, not having good back-up and not being able to see what you are doing. 

Some of the errors discussed in the book occurred in the process of learning. How can these be reduced? 

Checklists are a proven way of reducing errors. If you have to learn something without supervision, the checklist might be as simple as, "have I read the surgical text?", "have I discussed complications with the client?", "am I familiar with the anatomy of this area", "have I discussed this with my colleagues?". In short, have you done your due diligence in preparing yourself, the client and the patient before you start.

How can vets in general practice improve their surgery while minimising risks to patients? 

Be self-reflective and honest about their skills, have regular surgical rounds with colleagues or vets in other practices, debrief on mistakes they might have made, find ways to gain practical skills, like attending wet labs or doing cadaver dissections, and invest in the correct instrumentation (including lighting, suction and magnification) depending on how intricate the procedures are.

What is the difference between an error and a mistake? 

I suspect everyone would have a slightly different view of this, but in my vocabulary I think an error relates to judgement, and a mistake relates to technical performance. Both result in an adverse outcome that could have been avoided. Surgical sequelae are different; these may occur whether an error or mistake was made or not. 

You discussed the impact of errors on patients and clients, but also on the veterinary team. How do errors impact the vet team? 

This is complex. Students and techs can feel just as guilty as vets and they may feel more helpless, because they do not have primary responsibility for the case. Different members of the team might have different ethical positions, and in the case of students, they may be trying to work out what their ethical position should be. Students, techs and reception staff may have a closer bond with clients (or even the pet) than the veterinarian, as they have been involved in nursing and communications.

Some of the cases involve errors or misunderstandings in communication with clients or referring vets. How can errors of communication lead to bad outcomes? 

Errors in communication with clients will result in misalignment of expectations (costs, prognosis, time in hospital). Errors in communication with other members of the treatment team might result in incorrect dosing, delays in treatment, or even the wrong treatment. Communication is not just "telling", or "listening".; it can be difficult, and every vet should develop a technique to help them ensure that important concepts are not only communicated, but understood by the person with whom they are communicating. Likewise, we should reflect whether we are correctly interpreting things communicated by the people with whom we are working. 

Do you have any advice for future vets or veterinarians? 

You have great passion, talent and dedication. But you will face challenges and you will make mistakes. None of us are perfect. Develop your own safety net as you progress through your career. The whole group of people and patients to whom you are responsible, and with whom you work, will make a great support team if you allow them to.

Thank you Professor Hunt for your time. You can purchase Pitfalls in Veterinary Surgery through Wiley. 

Anaesthesia, anaesthetic awareness, risks and opportunities

Hero couldn't stay away from my copy of Anaesthesia: The Gift of Oblivion. 

Do animals experience anaesthetic awareness? I don’t know the answer, but the question is more complicated than you think. When a colleague asked me this question a few weeks ago, I went looking for literature and found very little. What I did discover was an incredible book, Anaesthesia: The Gift of Oblivion by journalistKate Cole-Adams.

She became intrigued by the question many years ago, when she met a woman at a dinner party who recounted being conscious during a caesarean when she had been given a general anaesthetic. The experience was traumatic, and had an ongoing impact on the patient. Hearing this story prompted Cole-Adams to undertake a decade-long exploration:

Each day specialist doctors known as anaesthetists (or, in America, anaesthesiologists) put hundreds of thousands of people like you and me into chemical comas to enable other doctors to enter and alter our insides. Then they bring us back again. It is mind-blowing. But quite how this daily extinction happens and un-happens remains uncertain. Researchers know that a general anaesthetic acts on the central nervous system – reacting with the slick membranes of the nerve cells in the brain to hijack responses such as sight, touch and awareness. They have nominated areas and processes they know are important: the microscopic channels through which neurons blast their chemical relays; the electrical circuits that pulse and groove between different regions of the brain. But they still can’t agree on just what it is that happens in those areas, or which of those things that happen matter the most, or why they sometimes happen differently with different anaesthetics, or even on the manner – a sunset? An eclipse? – in which the human brain segues from consciousness to not.

In interviews with anaesthetists, psychologists, hypnotists, scientists and people who have had experiences of anaesthetic awareness, Cole-Adams asks some of the philosophical questions about anaesthesia, like whether pain occurs when we are unconscious (and what the impact of that might be), and whether if it does occur, but is forgotten, it matters? What is the nature of this awareness, is it all one big hallucination, or something else?

Anaesthetic awareness isn’t something that simply happens when you underdose a patient who sits up halfway through surgery and eyeballs you. The subject may be completely “locked in”, unable to move, and oblivious to the medical team. It is said to be extremely rare, but surely is something we should be concerned about – after all, anaesthesia is meant to stop the patient from feeling, experiencing.

As Cole-Adams explains, anaesthetic awareness may not be bad per se, but it may have long term effects on the behaviour of the patient. This, she says, “carries risks and opportunities”. Suppose, for example, you could have a positive impact on clinical outcomes if you said positive things to the human patient while they are anaesthetised? Cole-Adams doesn’t explore what might happen to animals, but I found myself asking whether some of the strategies explored by scientists might improve outcomes in animal patients. For example, if our patients can hear, would it be beneficial to talk in reassuring tones? Human patients feel better if their name is spoken to them as they emerge from anaesthesia – what about dogs and cats? (How do we know or not know?).

Cole-Adams explores the concept of consciousness and what this means for humans. Do we have a continuous self? Are our loved ones simply a working hypothesis that we test through observation? Why might things we don’t know we know – things stored unconsciously – impact our behaviour. 

(One of my favourite passages is where she declares that “Consciousness is a small boat on an immense sea. We may learn to row, we may even rig up a sail, but we can’t know what’s beneath, let alone control it.” It reminds me of a painting by Helen Norton, called He Was In Control)

Post-operative cognitive dysfunction is a documented phenomenon in human patients – does it occur with animals? How could we detect it and, importantly, how could we prevent it?   

While my questions about animals weren’t answered in this book (Cole-Adams focuses on human patients), it is a fascinating combination of science and humanities, covering some amazing experiments and explaining why – although they could be done in the 1960s – today’s ethics committees would not approve, exploring the history of anaesthesia, and linking this with the subjective experience of patients. As a veterinarian, we don’t have access to the latter even by self-report, and there are some major differences between anaesthesia of humans and animals. We don’t, for example, use BIS (bispectral index) monitors to measure brain activity, and as far as I know there are no long-term studies looking at animal behaviour pre- and post- anaesthesia, or indeed looking at the impact of anaesthetic complications on post-operative behaviour in any systematic way.

I recommend this book to anyone interested in medical journalism and pathography, philosophy of science, anaesthesia or psychology. It is beautifully written, well-researched, and represents the fruit of a truly multidisciplinary “slow-burn” project.

Anaesthesia is available through Text Publishing.

Meeting the Syndaver Surgical Canine Model

A surgeon performs surgery on a synthetic dog.

Should veterinarians learn surgery on live animals? Do they even need to? This week I had the opportunity to perform surgery on a completely artificial dog. A high-fidelity model which simulates the feel of real tissue, has a pulse and will bleed if you cut blood vessel.

What is the point of this? Veterinarians perform surgery regularly. It’s not acceptable to learn on patients. For many years, veterinary schools around the world relied on the use of animals like dogs or pigs for terminal surgeries. If it’s not acceptable to learn surgery on a patient, how is it any more acceptable to learn on another animal?

This is greatly reduced, due largely to a combination of growing community concern about the welfare of animals used in teaching, an increased number of veterinary students and faculty conscientiously objecting to the use of live animals in teaching, and by into the “3Rs” of animal use – replacement of animal models where possible, reduction of numbers used and refinement of technique. There has also been better education and training of the educators – there is a growing recognition that surgery is a complex procedure which can be broken down into finite, trainable skills, many of which don’t need to be practiced on a patient at all.

I don’t tend to post on surgical topics so often here, because it’s an open site, but please note the photos below do NOT involve a real animal. The patient does, however, appear realistic and therefore the images may be distressing. Please use your discretion before scrolling down.

When I started veterinary school in 2000 at the University of Sydney I was very fortunate. The use of alternative models to live animals was actively being explored and I did not perform terminal surgery on live animals. We learned how to suture on sponges. We performed surgery on cadavers. It wasn’t the same as performing surgery on live animals, but allowed us to develop and hone our skills. Of course another key component of learning surgery is scrubbing in and assisting an experienced surgeon, and I had a lot of opportunity to do that.

Synthetic models have come a long way since I was in vet school. The Syndaver Surgical Canine, a synthetic canine model, is a remarkable example of such an alternative. It contains replaceable, very high-fidelity organs (a bladder which contains bladder stones, a small intestine which contains multiple areas of necrosis and some foreign bodies, a spleen, a uterus and ovaries, a liver and so on.

Dr Laurenci Brunel removes a "urolith" via a cystotomy on a simulated canine patient.

When I walked into the room it was kind of eerie. This was anatomically very similar to a real dog, and the circulation was impressive. A surgical specialist colleague scrubbed in and rapidly performed a cystotomy to remove bladder stones, and a splenectomy (we usually perform those to remove splenic masses). Other abdominal procedures which can be performed in this model include a gastrotomy with foreign body removal, gastropexy, liver lobe biopsy, partial liver lobectomy, enterotomy and foreign body removal, intestinal resection and anastomosis, intestinal biopsies, and of course ovariohysterectomy (surgical desexing). I had the privilege of undertaking a partial OHE in this model and it felt real. The manufacturers have managed to simulate the feel of the ovarian ligament, and even the broad ligament has built in fat.

The blood pressure can be turned up and down. I cut the ovarian artery on purpose (this was challenging as it went against my grain), and sure enough, it bled (I then clamped it).

Replacement organs.

The model also facilitates intubation, tracheostomy, mammary mass removal, skin and muscle suturing, intravenous catheterisation, chest tube placement, and surgical haemostasis.

Models like this don’t come cheap. They tend to be sold in a package with replacement organs, each of which retail for around $150USD each. High fidelity surgical models cost money. These can’t be mass produced. But the learning experience is impressive. If I could spend a weekend with a surgical tutor and one of these models, performing all of these surgeries, I would feel confident exploring new techniques. But as an undergraduate student, such a resource would have been invaluable.

This model can be customised to meet specific requirements. The costs may be prohibitive for small institutions, but as more institutions, organisations and individual use alternatives like this, the less costly they will be. And that is a good thing for both animals that might have been used in teaching, and future patients. You can find out more about the Syndaver Surgical Model here.

In other news, the Australian New Zealand College of Veterinary Scientists is conducting a survey of veterinary students about memberships here and one for veterinarians here.

Dogs in hospitals, brain surgery and biosecurity

Have you ever had to have a prolonged stay in hospital?

I recently spent some time with a human family member in a hospital. The staff were wonderful, but hospitals aren’t fun places to be. For a start, the patient is usually feeling anxious about their condition. And that condition is usually making them feel sick, and/or painful. For another thing, the patient has had to leave all their responsibilities at home – including companion animals who they may be missing terribly. And hospital can be a lonely place.

Should dogs be allowed in hospitals? The Royal College of Nursing in the UK has argued that there is scope to allow trained dogs on certain wards, and author Michele Hanson agrees. Read more here.

We’ve been reading neurosurgeon Henry Marsh’s books, Do No Harm and Admissions, a fascinating and scary-but-can’t-look-away insight into the challenges and grave responsibilities of brain surgery. If you don’t have time to read the books, you can listen to his interview with RichardFiedler here.

Are you a veterinarian who treats backyard livestock (this includes chickens)? The NSW Department of Primary Industries, Animal Health Australia and the AVA have teamed up to create an online course, which includes information on protecting staff and clients from zoonoses and other risks, and information about working with Government vets in disease surveillance. The course is free of charge and is open to veterinarians. For instructions on how to enrol, visit this site.

The acute abdomen, the philosophy of surgery, and why we need to look after our doctors

A gastrointestinal foreign body in situ - one of the most common causes of an acute abdomen in the dog. Not so much in human adults.

Have you ever wondered if your doctor has had a decent sleep, or a proper and nourishing meal? It was a question I was unexpectedly confronted with last week when a very close human family member was admitted to hospital with an acute abdomen. It became rapidly apparent that this was a surgical condition.

Due to a series of unfortunate events, the surgery was delayed. Patient X was meant to be transported to a larger hospital, but this didn’t occur due to the patient transport staff member calling in sick. As most surgeons know, at some critical point, time is bowel. So it was concerning that the surgery – scheduled for the morning – was not going to be addressed until late in the evening, when the on-call surgeon had been working constantly on critical cases and hadn’t had a break, and Patient X had been enduring discomfort for 48 hours. Free abdominal fluid had been detected on ultrasound.

To the team’s credit, everything went well. Patient X is recovering (I am so used to veterinary patients that I was shocked that I was able to converse with Patient X on the phone post anaesthesia. I wish our patients could call us and tell us things like “my throat is a bit sore from the ET tube” or “this pain relief is working really well”, or Whatsapp a cheery hospital selfie. It must at least be helpful to be hospitalised in a facility staffed by members of one’s own species). And no, it wasn't a foreign body but an obstruction which occurred secondary to an adhesion which occurred secondary to a previous surgery. (Disappointingly, at least for me, there was no surgical photo). 

The following day, when the surgical registrar called to update me, he was amused that I asked him if he’d had some sleep. But I was serious. We need to look after our health care professionals.

The French vascular surgeon Rene Leriche, in The Philosophy of Surgery, wrote that “The best surgeons are those who are able to maintain their fitness and comfort during the long-lasting jobs” back in 1951. (He also wrote that “Every surgeon carries about him a little cemetery, in which from time to time he goes to pray, a cemetery of bitterness and regret, of which he seeks the reason for certain of his failures” – an important acknowledgement, but somewhat concerning to recall when you know the patient, and you know there is a correlation between hypoglycaemia, hypohydration and errors).

I digress. It’s important that doctors are not overworked, are well-supported, take decent breaks, eat nourishing food and get recharging sleep. In an article last week in The Conversation, Professor Alex Broom put it succinctly: “Doctors who feel better will make fewer mistakes and solve problems faster.” (Read the full article here - he also makes the point that stressed doctors are less motivated to participate in continuing education, yet “participation in continuing education improves professional practice, and, crucially, patient outcomes”).

The Australian Medical Association lists some excellent resources on its website, many of which are just as relevant to veterinarians and nurses too. You can access those here.

We need to look after those people that look after others. In terms of vets, we’re working on The Vet Cook Book which should be published later this year. This is designed to promote collegiality and conversation but also provides some helpful resources – and recipes. You can follow the facebook page. 

Fortunately, and thanks to excellent care despite many challenges, patient X is doing well, having been discharged home for cage bed rest (without an Elizabethan collar).

In other news, an exhibition which opened on June 9 highlights the plight of victims of domestic violence and their companion animals. This looks like an amazing initiative and worth seeing.

If you’re in Sydney, SAT reader Kerry shared this info about doggy degustation events (obviously not for the canine on an elimination or prescription diet).

Confessions of a surgeon: Henry Marsh

Every surgeon carries within himself a small cemetery, where from time to time he goes to pray – a place of bitterness and regret, where he must look for an explanation for his failures. – Rene Leriche, La philosophie de la chirurgie, 1951

It’s not a quote you’d expect to open the autobiography of an accomplished, decorated neurosurgeon, yet Henry Marsh opens Do No Harm: Stories of Life, Death and BrainSurgery with these words.

They set the tone for a very honest account of his work – the risks (his perception versus the patient), his own anxieties and ego, the very grave consequences (a poor decision to take a few millimetres additional margin, or to retreat, can mean death, or possibly worse, for his patients), cutting though matter that holds personality, dreams, language, reason.

His patients aren’t animals, but anyone who does surgery or works in a surgical theatre, or perhaps those who have undergone neurosurgery, will be fascinated to read these cases.

And if you’re in Sydney you can meet him this weekend. Henry Marsh will be speaking at the Sydney Writer’s Festival. There are still tickets available here.

You can read an extended review of his book here.

Why are foreign bodies such bad news and why is intestinal surgery risky?

Unhappy intestines. The foreign body is distending this dog's intestine, compromising blood supply.

Radiographs can tell incredible stories, and often the best radiographic stories relate to foreign bodies: things that should not be inside animals that are inadvertently ingested.

Every year, Veterinary Practice News runs their ”They ate what?!” imaging competition, to highlight the more unusual items dogs, cats and other species swallow. You can review the impressive results here, and nope, you don't have to work as a vet, nurse or student to interpret most of these x-rays.

The foreign body once removed - a piece of rubber from a toy.

Such as 26 golf balls (all swallowed by one dog). Or a fishing pole. Gorilla glue, hair ties, a plastic dinosaur, steel wool pads, teddy bears and rocks also feature. The radiographs presented give an indication of just how problematic foreign bodies can be, without the full-colour gore we see on the operating table.

They make for great stories, but foreign bodies are life-threatening. As mentioned in the results of the competition, unfortunately not all of the patients made it. Why not?

Even in the best hands, intestinal repairs can break down (the overall rate of intestinal incision breakdown, or dehiscence, is 12-16 per cent). The risk of such complications is much higher in animals over time, i.e. the longer the foreign body is present, the higher the risk. The risk is also higher in animals that are systemically unwell, septic or those who have had a previous surgery.

There is a fabulous article by Sabrina Barry explaining all of this in the latest issue of Clinician’s Brief. Following surgery, intestine undergoes inflammation in the early stages of healing. Inflammation actually reduces the holding strength of the wound – so there is a real race between collagen breakdown and collagen synthesis.

Barry recommends supporting tissue oxygen delivery to the GIT, minimising contamination, being mindful of vascular anatomy, minimising inflammation and ensuring vascular wound edges, engaging the submucosa during suturing (even though its softer than the muscular layer, the submucosa is the layer that maintains its integrity when other tissues at the wound edge have lost their strength), approximating submucosal edges, minimising the number of enterotomies, preserving the omentum and offering early nutrition.

This is a lovely article and well worth a read for anyone who performs intestinal surgery.

However, you can do all of these things and an intestinal incision can still break down. As Barry points out, intestinal incisions aren’t like skin incisions – we can’t inspect them regularly, treat them topically or just throw in a few additional sutures if we think the wound needs reinforcing. And foreign bodies can wreak total devastation on the gut, especially those with sharp or abrasive edges.

Prevention is the best bet. Often, foreign body eaters are repeat offenders. I’ve surgically retrieved foreign objects from the same patient (almost invariably a dog) up to four times. They don’t associate eating the thing they ate with gut pain, nausea, hospitalisation or surgery.

If you notice your animal swallowing things they should not in your presence, it’s reasonable to expect they will do so in your absence. Toddler-proof your home, lock your laundry basket, put the garbage bins out of reach, block access to the compost – it’s worth the inconvenience.

And if you see your pet swallow something, seek immediate veterinary attention. Sometimes these objects can be retrieved by inducing vomiting or endoscopy, before they hit the intestines.

Reference

Barry, SL (2016) Intedyinal incision dehiscence. Clinician’s Brief April 2016: 71-76.

Lessons learned in soft tissue surgery: tips from top surgeons

Soft tissue surgery can be rewarding, but it can also present hard challenges.

What are the mantras that the profession’s best surgeons live by? I was recently able to pick the brains of three specialist veterinary surgeons about their top tips. The trio are converging in Melbourne from May15-18 to present a course on soft tissue and reconstructive surgery. Together they have over 100 years of surgical experience.

Bryden Stanley BVMS MACVSc MVetSc Dip ACVS is the section head of surgery at Michigan State University College of Veterinary Medicine.

Dr Stanley and colleagues perform a procedure.

Her tips are:

• Halsted’s Principles – learn them and love them.
• Know your anatomy – inside out.
• Pay attention to detail - never think, “that’ll do”.

Dr Stanley performing surgery.

Above is a short video showing just how many people are involved in specialist small animal surgery. The video was made by Dr Kyle Snowdon. The surgeons are Dr Bryden Stanley and Chief Resident Lindsey Kurach. The patient had chylothorax.

Good surgeons love their loupes. Professor Hunt uses them in a procedure.

Geraldine Hunt BVSc MVetClinStud PhD is Professor of Surgical and Radiological Sciences at UC Davis. Professor Hunt was one of my teachers of surgery and I watched her perform many incredible procedures including correction of portosystemic shunts and open heart surgery. She was unflappable.

Her tips are:

• Have a good decision making process
• Ensure you are clear on the goals of your surgery
• Don't be afraid to re-evaluate your plan in light of additional information

Professor Hunt with colleagues and students.

Arthur House BVSc PhD Cert SAS Dip ECVS is an Australian and European specialist small animal surgeon.

Dr House meets an elephant at the WSAVA conference.

Early on in my career when I thought that I would like to pursue specialist surgery a friend (and specialist in surgery) said to me that 'you can teach a monkey to do tricks but a good surgeon knows when to do tricks'. He is absolutely correct.  In addition, to be a good surgeon you have to

• have the ability to always question your diagnosis and be prepared to be wrong and reconsider i.e. keep searching. This can be only achieved if you have a comprehensive knowledge base;
• consider and fully understand all treatment options, be realistic with what you as an individual and collectively as a practice / hospital can achieve and do not be fixated with only surgical choices;  
• be able to manage all complications and not accept euthanasia as an acceptable outcome;
• accept only the optimal treatment - even at 11pm after a 16h day. 

Using a 3D printed porous titanium radius implant in a limb sparing surgery.

Behind every great surgeon...a candid image of Dr House's slightly plus-size moggy kipping
on the rug (and snoring!).

The three surgeons are getting together in Melbourne next week to teach a course on soft tissue surgery through the Centre for Veterinary Education. For more info about the course, click here.

Complication

Hero experienced complications following his surgery. You wouldn't know it now.

Feline urinary tract disease can be challenging and frustrating to treat. Recurrence of obstruction is common, although the reasons can vary. When I treated my cat Hero for urethraland bladder stones over Christmas he seemed to be recovering well. But he experienced a complication.

I want to discuss it here because a) complications are a normal part of medicine and surgery and I think we need to discuss them more; b) turns out this one is a lot more common than I thought and c) I’ll feel more like Hero didn’t suffer the experience in vain if others can learn from it. And suffer he did. Suffer everyone around him did. Many sleepless nights were had over the festive season and none of them were the celebratory sleepless kind!

It was day four post-op. Hero had been eating, drinking and becoming more active. He seemed bright and happy. His surgical wound looked beautiful. Then I watched him go to the litter tray. Not once to pass a nice stream, but twice. And he passed a few drops. And cried. My heart sank.

I palpated his bladder. It was large, despite the fact that he’d just “voided”. He reacted when I touched his tummy. There had to be a stone obstructing that little urethra of his. It sent my mind my mind into a vortex of retrospectoscopy…

At the time of surgery we counted the stones on radiographs and those we retrieved, and thought there may be a discrepancy. His first wee post-op had contained more blood than I’d hoped. The patches of urine in the litter tray were getting subtlely smaller.  I’m not going to lie. I did not like what this was telling me and did the whole “oh Anne, you’re just being a paranoid hyperchondriac by proxy”. It’s easy to do. But a little voice inside me said “or is this a complication?”.

Potential complications of cystotomy including uroabdomen (urine leaks into the abdominal cavity), urinary tract infection, surgical site infection, recurrence of stones (usually secondary to infection), lower urinary tract obstruction (mechanical or functional) and incomplete removal of uroliths (Appel et al 2012). I was concerned about the latter.

When it comes to uroliths that hang around post-cystotomy, MOST of these can be prevented by passing a urinary catheter and flushing stones back into the bladder intra-operatively, or - as US veterinary surgeon Howie Seim does in his fantastic video on urinary tract surgery – performing the “urogenital floss”.

In addition, post-operative radiographs of the entire urethra following surgery can identify stones that are left. A review of literature on veterinary cystotomies found that radiographically detectable uroliths remained in 14 to 20 per cent of dogs (Grant et al 2010).

BUT not all uroliths are radiographically detectable. Even if they show up on the rads, if they’re hiding behind the pelvis or beside a catheter in the lateral view, or below the spine on the ventrodorsal view, you won’t see them. How can they escape a catheter? Well, if they’re narrow enough a catheter can slip past them. You can urogenital floss all you like but there’s a chance they won’t be dislodged.

In a Canadian study of 106 veterinarians who performed cystotomies, 42 per cent reported that patients had recurrent uroliths, although it’s hard to know how many of these were true recurrences as opposed to those not removed at surgery. When I did the ring-around, lots of colleagues had experienced the pain (indirectly, of course – it’s the patient who feels it first-hand) of a retained stone.

But the data illustrates that even in the best hands (ie world-class veterinary teaching and referral hospitals) some uroliths inevitably escape the surgeon. Post-op rads confirmed my worst nightmare. A urolith the size of Tasmania (almost) in his distal urethra. I won’t lie: I felt sick. But I couldn’t leave that stone in there.

Evil, evil urolith.

Flushed retrograde into the bladder to allow it to be retrieved via cystotomy (bladder surgery) rather than by traumatising the urethra further. Why do that? Trauma to the uretha may cause scarring which can cause major problems in cats and may require removal of the end of the urethra (and the penis with it) - a procedure called a perineal urethrostomy. Worth doing if you have to but worth avoiding if you can.

So I flushed it back into his bladder and performed the second cystotomy in four days on little Hero. Are there alternatives? In humans, cystotomy is rare these days. In the US, open-surgical removal of uroliths was described in only 0.3-4 per cent of human patients (Defarges et al 2013). But non-invasive alternatives aren’t well established in companion animals. Voiding urohydropulsion is contraindicated in male cats because of the high risk of obstruction (sorry to say it Hero, but male cats have a tiny penis with a narrow urethra that is easily blocked), lithotripsy is still experimental, and laparoscopy remains uncommon in first-opinion practice.

My concern was that he was in pain. His urine was full of blood and that stone was tearing his urethral mucosa. The surgery was straightforward. Cystotomies are beautiful surgeries and I’ve said before that the bladder and urethra have extraordinary healing capacity. When I opened him up there was Hero’s bladder looking quite healthy despite being opened four days earlier.

I incised once again, locating and removing the stone within minutes. Its removal was confirmed (as much as it could be) on radiographs. Again I used multimodal analgesia (multiple drugs) to minimise his pain and of course checked on him through the night.

The following morning I helped him into his litter tray (he had kept the drip on overnight this time) and his post-operative wee was like Niagra Falls compared to the first post-op wee.

MUCH BETTER.

A few lessons learned here…

1. The first, which I didn’t realise, is that the incidence of uroliths leftover after surgery (even in the hands of a specialist) is higher than I thought.
2. The urogenital floss is good – but doesn’t prevent sneaky uroliths from hiding out in the pelvic urethra. And a catheter can pass adjacent to a particularly recalcitrant urolith embedded in the urethral wall.
3. Post-cystotomy radiographs are essential but don’t absolutely rule out uroliths. In retrospect I should have taken a post-op rad of Hero WITHOUT the urinary catheter in just to be sure there was nothing in the urethra hiding beside the catheter.
4. Know your cat’s wee. I was celebrating about a post-op wee that wasn’t as voluminous as it should have been.
5. Phone a friend. I called a specialist friend for a debrief after cystotomy number two. He was the one who suggested I look at the literature about incompletely removed uroliths, and I have to say that was both educational and therapeutic.

Of course, all of this fiddling with Hero’s urethra – all done as gently as possible – wasn’t unnoticed by his urethral mucosa. Predictably, he developed a functional urethral obstruction (essentially his urethra just threw a hissy and clamped shut). 

So he was readmitted, I placed an indwelling urinary catheter, and kept Hero in hospital. Then plan was 48 hours of catherisation. Despite the world’s biggest Elizabethan collar, Feliway, a private cat grass/mint/nip garden in his cage and drugs galore, he protested. He removed collars. He removed catheters (urinary and intravenous), he threw a rockstar rampage in his cage and misbehaved for colleagues. But he put in 36 hours before I caved and took him home.

The urolith analysis returned a result of 100 per cent calcium oxalate. These types of stones tend to be sharp and prickly, whereas struvite (the other very common stone in cats) produces very smooth stones. So I had an inkling.

The bummer about calcium oxalate uroliths is that they can return after months or years even with IDEAL management. So whilst modifying Hero’s diet will hopefully slow the rate of recurrence, we’ll need to be vigilant. Fortunately I’ve taught him to tolerate a daily bladder palpation session by convincing him it’s a weird new patting style.

Interestingly, a very close family member of the human variety has experienced the woe that is a kidney stone. The medical team didn’t bother with x-rays and instead performed a CT scan to detect the 3mm-diameter offender (but amazingly, didn't show him a picture of it). In twenty years we might all be doing pre-and post- or even intra-op CTs or cystoscopies (with tiny, tiny, tiny cat-penis sized scopes) and we will be laughing about “ye olde days” when people had to worry about sneaky uroliths evading detection.

References

Appel S, Otto SJ & Weese JS (2012) Cystotomy practices and complications among general small animal practitioners in Ontario, Canada. Canadian Veterinary Journal 53 (March):303-310.

Defarges A, Dunn M & Berent A (2013) New alternatives for minimally invasive management of uroliths: lower urinary tract uroliths. Compendium: Continuing Education for Veterinarians January 2013:E1-E7.

Grant DC, Harper TAM & Were SR (2010) Frequency of incomplete uroliths removal, complications, and diagnostic imaging following cystotomy for removal of uroliths from the lower urinary tract in dogs: 128 cases (1994-2006).